Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
Features
Single 1.7V to 5.5V supply
Measures temperature from -55C to +125C
Highly accurate temperature measurements requiring no external components
±0.5°C accuracy (typical) over the 0C to +85C range
±1.0°C accuracy (typical) over the -25C to +105C range
±2.0°C accuracy (typical) over the -40C to +125C range
User-configurable resolution
9 to 12 bits (0.5C to 0.0625C)
User-configurable high and low temperature limits
Nonvolatile registers to retain user-configured or pre-defined power-up defaults
Register locking to prevent erroneous misconfiguration
Register lockdown for permanent, non-changeable device configuration
ALERT output pin for indicating temperature alarms
2-wire I2C and SMBus™ compatible serial interface
Supports SMBus Timeout
Supports SMBus Alert and Alert Response Address (ARA)
Selectable addressing allows up to eight devices on the same bus
Built-in noise suppression filtering for clock and data input signals
Low power dissipation
75μA active current (typical) during temperature measurements
Shutdown mode to minimize power consumption
1μA shutdown current (typical)
One-Shot mode for single temperature measurement while in Shutdown mode
Pin and software compatible to industry-standard LM75-type devices
Industry standard green (Pb/Halide-free/RoHS compliant) package options
8-lead SOIC (150-mil)
8-lead MSOP (3.0 x 3.0mm)
8-pad Ultra Thin DFN (UDFN — 2.0 x 3.0 x 0.6mm)
AT30TS750A
9- to 12-bit Selectable, ±0.5°C Accurate
Digital Temperature Sensor with Nonvolatile Registers
DATASHEET
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
2
Table of Contents
1. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Pin Descriptions and Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Device Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1 Start Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2 Stop Condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.3 Acknowledge (ACK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.4 No-Acknowledge (NACK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Device Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 Temperature Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2 Temperature Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2.1 Fault Tolerance Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2.2 Comparator Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2.3 Interrupt Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.3 Shutdown Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.3.1 One-Shot Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6. Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1 Pointer Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.2 Temperature Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.3 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.3.1 OS Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.3.2 R1:R0 Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.3.3 FT1:FT0 Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.3.4 POL Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.3.5 CMP/INT Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.3.6 SD Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.3.7 NVRBSY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.4 Nonvolatile Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.4.1 NVR1: NVR0 Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.4.2 NVFT1:NVFT0 Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.4.3 NVPOL Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.4.4 NVCMP/INT Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.4.5 NVSD Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.4.6 RLCKDWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.4.7 RLCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6.5 TLOW and THIGH Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.6 Nonvolatile TLOW and THIGH Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7. Register Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
8. Operations Allowed During Nonvolatile Busy Status . . . . . . . . . . . . . . . 31
9. Other Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
9.1 Copy Nonvolatile Registers to Volatile Registers . . . . . . . . . . . . . . . . . . . . . . 32
9.2 Copy Volatile Registers to Nonvolatile Registers . . . . . . . . . . . . . . . . . . . . . . 33
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AT30TS750A [DATASHEET]
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10. SMBus Features and I2C General Call . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
10.1 SMBus Alert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
10.2 SMBus Timeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
10.3 General Call . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
11. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
11.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
11.2 DC and AC Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
11.3 DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
11.4 Temperature Sensor Accuracy and Conversion Characteristics . . . . . . . . . . 38
11.5 AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
11.6 Nonvolatile Register Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.7 Power-Up Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.8 Pin Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
11.9 Input Test Waveforms and Measurement Levels . . . . . . . . . . . . . . . . . . . . . . 40
11.10 Output Test Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
12. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
12.1 Atmel Ordering Code Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
12.2 Green Package Options (Pb/Halide-free/RoHS Compliant) . . . . . . . . . . . . . . 41
13. Part Marking Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
14. Packaging Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
14.1 8S1 — 8-lead JEDEC SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
14.2 8XM — 8-lead MSOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
14.3 8MA2 — 8-pad UDFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
15. Errata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
15.1 No Errata. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
16. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
AT30TS750A [DATASHEET]
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1. Description
The Atmel® AT30TS750A is a complete, precise temperature monitoring device designed for use in a variety of
applications that require the measuring of local temperatures as an integral part of the system's function and/or reliability.
The AT30TS750A device combines a high-precision digital temperature sensor, programmable high and low
temperature alarms, and a 2-wire I2C and SMBus (System Management Bus) compatible serial interface into a single,
compact package.
The temperature sensor can measure temperatures over the full -55°C to +125°C temperature range and has a typical
accuracy as precise as ±0.5°C from 0°C to +85°C. The result of the digitized temperature measurements are stored in
one of the AT30TS750A's internal registers, which is readable at any time through the device's serial interface.
The AT30TS750A utilizes flexible, user-programmable internal registers to configure the temperature sensor's
performance and response to high and low temperature conditions. The device also contains a set of Nonvolatile
Registers to retain the configuration and temperature limit settings even after the device has been power cycled, thereby
eliminating the need for the device to be reconfigured after each Power-up operation. This additional flexibility permits
the device to run self-contained and not rely upon a Host controller for device configuration.
A dedicated alarm output activates if the temperature measurement exceeds the user-defined temperature and fault
count limits. To reduce current consumption and save power, the AT30TS750A features a Shutdown mode that turns off
all internal circuitry except for the internal Power-On Reset (POR) and serial interface circuits. The device can also be
configured to power-up in the Shutdown mode to ensure that the device remains in a low-power state until the user
wishes to perform temperature measurements.
The AT30TS750A is factory-calibrated and requires no external components to measure temperature. With it’s flexibility
and high-degree of accuracy, the AT30TS750A is ideal for extended temperature measurements in a wide variety of
communication, computer, consumer, environmental, industrial, and instrumentation applications.
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AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
2. Pin Descriptions and Pinouts
Table 1. Pin Description
Symbol Name and Function
Asserted
State Type
SCL Serial Clock: This pin is used to provide a clock to the device and is used to control
the flow of data to and from the device. Command and input data present on the SDA
pin is always latched in on the rising edge of SCL, while output data on the SDA pin is
always clocked out on the falling edge of SCL.
The SCL pin must either be forced high when the serial bus is idle or pulled-high using
an external pull-up resistor.
— Input
SDA Serial Data: The SDA pin is an open-drain bidirectional input/output pin used to
serially transfer data to and from the device.
The SDA pin must be pulled-high using an external pull-up resistor and may be
wire-ANDed with any number of other open-drain or open-collector pins from other
devices on the same bus.
— Input/Output
ALERT Alert: The ALERT pin is an open-drain output pin used to indicate when the
temperature goes beyond the user-programmed temperature limits. The ALERT pin
can be operated in one of two different modes (Interrupt or Comparator mode) as
defined by the CMP/INT bit in the Configuration Register. The ALERT pin defaults to
an active-low output upon device power-up or reset but can be reconfigured as an
active-high output by setting the POL bit in the Configuration Register.
This pin can be wire-ANDed together with ALERT pins from other devices on the same
bus. When wire-ANDing pins together, the ALERT pin should be configured as an
active-low output so that when a single ALERT pin on the common alert bus goes
active, the entire common alert bus will go low and the host controller will be properly
notified since other ALERT pins that may be in the inactive-high state will not mask the
true alert signal. In an SMBus environment, the SMBus Host can respond by sending
an SMBus ARA (Alert Response Address) command to determine which device on the
SMBus generated the alert signal.
The ALERT pin must be pulled-high using an external pull-up resistor even when it is
not used. Care must also be taken to prevent this pin from being shorted directly to
ground without a resistor at any time whether during testing or normal operation.
— Output
A2-0 Address Inputs: The A2-0 pins are used to select the device address and correspond
to the three least-significant bits (LSBs) of the I2C/SMBus 7-bit slave address. These
pins can be directly connected in any combination to VCC or GND, and by utilizing the
A2-0 pins, up to eight devices may be addressed on a single bus.
The A2-0 pins are internally pulled to GND and may be left floating; however, it is highly
recommended that the A2-0 pins always be directly connected to VCC or GND to ensure
a known address state.
— Input
VCC Device Power Supply: The VCC pin is used to supply the source voltage to the device.
Operations at invalid VCC voltages may produce spurious results and should not be
attempted.
— Power
GND Ground: The ground reference for the power supply. GND should be connected to the
system ground. — Power
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Figure 1. Pin Configurations
3. Block Diagram
Figure 3-1. Block Diagram
8-SOIC
(Top View)
8-MSOP
(Top View)
8-UDFN
(Top View)
SDA
SCL
A
LERT
GND
VCC
A0
A1
A2
SDA
SCL
ALERT
GND
SDA
SCL
ALERT
GND
VCC
A0
A1
A2
VCC
A0
A1
A2
1
2
3
4
8
7
6
5
1
2
3
4
8
7
6
5
1
2
3
4
8
7
6
5
SCL
SDA
A2-0
A
LERT
3
Digital
Comparator
A/D
Converter
Temperature
Sensor
Temperature
Register
TLOW Limit
Register
THIGH Limit
Register
Configuration
Register
Pointer
Register
I2C/SMBus
Interface
Control
and
Logic
Nonvolatile
Configuration
Register
Nonvolatile
THIGH Limit
Register
Nonvolatile
TLOW Limit
Register
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AT30TS750A [DATASHEET]
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4. Device Communication
The AT30TS750A operates as a slave device and utilizes a simple 2-wire I2C and SMBus compatible digital serial
interface to communicate with a Host controller, commonly referred to as the bus Master. The Master initiates and
controls all Read and Write operations to the slave devices on the serial bus, and both the Master and the slave devices
can transmit and receive data on the bus.
The serial interface is comprised of just two signal lines: Serial Clock (SCL) and Serial Data (SDA). The SCL pin is used
to receive the clock signal from the Master, while the bidirectional SDA pin is used to receive command and data
information from the Master as well as to send data back to the Master. Data is always latched into the AT30TS750A on
the rising edge of SCL and always output from the device on the falling edge of SCL. Both the SCL and SDA pin
incorporate integrated spike suppression filters and Schmitt triggers to minimize the effects of input spikes and bus noise.
All command and data information is transferred with the Most-Significant Bit (MSB) first. During bus communication, one
data bit is transmitted every clock cycle, and after eight bits (one byte) of data has been transferred, the receiving device
must respond with either an acknowledge (ACK) or a no-acknowledge (NACK) response bit during a ninth clock cycle
(ACK/NACK clock cycle) generated by the Master; therefore, nine clock cycles are required for every one byte of data
transferred. There are no unused clock cycles during any Read or Write operation, so there must not be any interruptions
or breaks in the data stream during each data byte transfer and ACK or NACK clock cycle.
During data transfers, data on the SDA pin must only change while SCL is low, and the data must remain stable while
SCL is high. If data on the SDA pin changes while SCL is high, then either a Start or a Stop condition will occur. Start and
Stop conditions are used to initiate and end all serial bus communication between the Master and the slave devices. The
number of data bytes transferred between a Start and a Stop condition is not limited and is determined by the Master.
In order for the serial bus to be idle, both the SCL and SDA pins must be in the logic-high state at the same time.
4.1 Start Condition
A Start condition occurs when there is a high-to-low transition on the SDA pin while the SCL pin is stable in the logic-high
state. The Master uses a Start condition to initiate any data transfer sequence, and the Start condition must precede any
command. The AT30TS750A will continuously monitor the SDA and SCL pins for a Start condition, and the device will
not respond unless one is given.
4.2 Stop Condition
A Stop condition occurs when there is a low-to-high transition on the SDA pin while the SCL pin is stable in the logic-high
state. The Master uses the Stop condition to end a data transfer sequence to the AT30TS750A which will subsequently
return to the idle state. The Master can also utilize a repeated Start condition instead of a Stop condition to end the
current data transfer if the Master will perform another operation.
4.3 Acknowledge (ACK)
After every byte of data received, the AT30TS750A must acknowledge to the Master that it has successfully received the
data byte by responding with an ACK. This is accomplished by the Master first releasing the SDA line and providing the
ACK/NACK clock cycle (a ninth clock cycle for every byte). During the ACK/NACK clock cycle, the AT30TS750A must
output a Logic 0 (ACK) for the entire clock cycle such that the SDA line must be stable in the logic-low state during the
entire high period of the clock cycle.
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4.4 No-Acknowledge (NACK)
When the AT30TS750A is transmitting data to the Master, the Master can indicate that it is done receiving data and
wants to end the operation by sending a NACK response to the AT30TS750A instead of an ACK response. This is
accomplished by the Master outputting a Logic 1 during the ACK/NACK clock cycle, at which point the AT30TS750A will
release the SDA line so that the Master can then generate a Stop condition.
In addition, the AT30TS750A can use a NACK to respond to the Master instead of an ACK for certain invalid operation
cases such as an attempt to write to a Read-only Register (e.g. an attempt to write to the Temperature Register).
Figure 4-1. Start, Stop, and ACK
SCL
SDA
Start
Condition Data
Change
Allowed
Data
Change
Allowed
Data
Change
Allowed
Data
Change
Allowed
ACK
Stop
Condition
Data
Must be
Stable
Data
Must be
Stable
Data
Must be
Stable
128
9
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5. Device Operation
Commands used to configure and control the operation of the AT30TS750A are sent to the device from the Master via
the serial interface. Likewise, the Master can read the temperature data from the AT30TS750A via the serial interface;
however, since multiple slave devices can reside on the serial bus, each slave device must have its own unique 7-bit
address so that the Master can access each device independently.
For the AT30TS750A, the first four MSBs of its 7-bit address are the device type identifier and are fixed at 1001. The
remaining three LSBs correspond to the states of the hard-wired A2-0 address pins.
Example: If the A2-0 pins are connected to GND, then the 7-bit device address would be 1001000.
In order for the Master to select and access the AT30TS750A, the Master must first initiate a Start condition. Following
the Start condition, the Master must output the device address byte. The device address byte consists of the 7-bit device
address plus a Read/Write (R/W) control bit, which indicates whether the Master will be performing a Read or a Write to
the AT30TS750A. If the R/W control bit is a Logic 1, then the Master will be reading data from the AT30TS750A.
Alternatively, if the R/W control bit is a Logic 0, then the Master will be writing data to the AT30TS750A.
Table 5-1. AT30TS750A Address Byte
If the 7-bit address sent by the Master matches that of the AT30TS750A, then the device will respond with an ACK after
it has received the full address byte. If there is an address mismatch, then the AT30TS750A will respond with a NACK
and return to the idle state.
5.1 Temperature Measurements
The AT30TS750A utilizes a band-gap type temperature sensor with an internal sigma-delta Analog-to-Digital Converter
(ADC) to measure and convert the temperature reading into a digital value with a selectable resolution as high as
0.0625C. The measured temperature is calibrated in degrees Celsius; therefore, a lookup table or conversion routine is
necessary for applications that wish to deal in degrees Fahrenheit.
The result of the digitized temperature measurements are stored in the internal Temperature Register of the
AT30TS750A, which is readable at any time through the device's serial interface. When in the normal operating mode,
the device performs continuous temperature measurements and updates the contents of the Temperature Register (see
Section 6.2, “Temperature Register” on page 16) after each analog-to-digital conversion.
The resolution of the temperature measurement data can be configured to 9, 10, 11, or 12 bits which corresponds to
temperature increments of 0.5C, 0.25C, 0.125C, and 0.0625C, respectively. Selecting the temperature resolution is
done by setting the R1 and R0 bits in the Configuration Register (see Section 6.3, “Configuration Register” on page 18).
The ADC conversion time does increase with each bit of higher resolution, so careful consideration should be given to
the resolution versus conversion time relationship. The resolution after device power-up or reset will revert to what was
previously selected using the NVR1 and NVR0 bits of the Nonvolatile Configuration Register bits prior to when the device
was powered-down or reset.
With 12 bits of resolution, the AT30TS750A can theoretically measure a temperature range of 255C (-128C to +127C);
however, the device is only designed to measure temperatures over a range of -55C to +125C.
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Device Type Identifier Device Address Read/Write
1 0 0 1 A2 A1 A0 R/W
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5.2 Temperature Alarm
After the measured temperature value has been stored into the Temperature Register, the data will be compared with
both the high and low temperature limits defined by the values stored in the THIGH Limit Register and TLOW Limit Register.
If the comparison results in a valid fault condition (see Section 5.2.1, “Fault Tolerance Limits” on page 10), then the
device will activate the ALERT output pin.
The polarity and function of the ALERT pin can be configured by using specific bits in the Configuration Register. The
polarity of the ALERT pin is controlled by the POL bit in the Configuration Register while the function of the ALERT pin
changes based on the Alarm Thermostat mode, which can be configured to either Comparator mode (see Section 5.2.2,
“Comparator Mode” on page 11) or Interrupt mode (see Section 5.2.3, “Interrupt Mode” on page 12) by using the
CMP/INT bit in the Configuration Register. After the device powers up or resets, the NVPOL and NVCMP/INT bits of the
Nonvolatile Configuration Register are automatically copied into the POL and CMP/INT bits of the Configuration
Register; therefore, the ALERT pin polarity and function will revert back to the settings defined by the NVPOL and
NVCMP/INT bits prior to when the device was powered-down or reset.
The value of the high temperature limit stored in the THIGH Limit Register must be greater than the value of the low
temperature limit stored in the TLOW Limit Register in order for the ALERT function to work properly; otherwise, the
ALERT pin will output erroneous results and will falsely signal temperature alarms.
5.2.1 Fault Tolerance Limits
A temperature fault occurs if the measured temperature meets or exceeds either the high temperature limit set by the
THIGH Limit Register or the low temperature limit set by the TLOW Limit Register. To prevent false alarms due to
environmental or temperature noise, the device incorporates a fault tolerance queue that requires consecutive
temperature faults to occur before resulting in a valid fault condition. The fault tolerance queue value is controlled by the
FT1 and FT0 bits in the Configuration Register and can be set to a single fault count of one or a count of two, four, or six
consecutive faults.
An internal counter that automatically increments after a temperature fault is used to determine if the fault tolerance
queue setting has been met. After incrementing the fault counter, the device will compare the count to the fault tolerance
queue setting to see if a valid fault condition should be triggered. Once a valid fault condition occurs, the device will
activate the ALERT output pin. If the most recent measured temperature does not meet or exceed the high or low
temperature limit, then the internal fault counter will be reset back to zero.
Figure 5-1 shows a sample temperature profile and how each temperature fault would impact the internal fault counter.
Figure 5-1. Fault Count Example
After the device powers up or resets, the NVFT1 and NVFT0 bits of the Nonvolatile Configuration Register are
automatically copied into the FT1 and FT0 bits of the Configuration Register; therefore, the Fault Tolerance Queue
setting will revert back to the settings defined by the NVFT1and NVFT0 bits prior to when the device was powered down
or reset.
Temperature Measurements/Conversions
THIGH Limit
Temperature
TLOW Limit
11
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
5.2.2 Comparator Mode
When the device operates in the Comparator mode, then the ALERT pin goes active if the measured temperature meets
or exceeds the high temperature limit set by the THIGH Limit Register and a valid fault condition exists (the consecutive
number of temperature faults has been reached). The ALERT pin will return to the inactive state after the measured
temperature drops below the TLOW Limit Register value the appropriate number of times to create a subsequent valid
fault condition. The ALERT pin only changes state based on the high and low temperature limits and fault conditions;
reading from or writing to any register or putting the device into Shutdown mode will not affect the state of the ALERT pin.
The high temperature limit set by the THIGH Limit Register must be greater than the low temperature limit set by the TLOW
Limit Register in order for the ALERT pin to activate correctly.
If switching from Interrupt mode to Comparator mode while the ALERT pin is already active, then the ALERT pin will
remain active until the measured temperature is below the TLOW Limit Register value the appropriate number of times to
create a valid fault condition.
The ALERT pin will return to the inactive state if the device receives the General Call Reset command. When reset, the
contents of the Nonvolatile Configuration Register will be copied into the Configuration Register; therefore, the device
may or may not return to the Comparator mode depending on the setting of the NVCMP/INT bit in the Nonvolatile
Configuration Register.
Figure 5-2 illustrates both the active high and active low ALERT pin response for a sample temperature profile with the
device configured for the Comparator mode and a fault tolerance queue setting of two.
Figure 5-2. Comparator Mode (Fault Tolerance Queue = 2)
Temperature Measurements/Conversions
THIGH Limit
Temperature
TLOW Limit
ALERT
(Active High, POL = 1)
ALERT
(Active Low, POL = 0)
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
12
5.2.3 Interrupt Mode
Similar to the Comparator mode, when the device operates in the Interrupt mode, the ALERT pin will go active if the
measured temperature meets or exceeds the high temperature limit set by the THIGH Limit Register and a valid fault
condition exists (the consecutive number of temperature faults has been reached). Unlike the Comparator mode,
however, the ALERT pin will remain active until one of three normal operation events takes place: any one of the device's
registers is read, the device responds to an SMBus Alert Response Address (ARA), or the device is put into Shutdown
mode.
Once the ALERT pin returns to the inactive state, it will not go active again until the measured temperature drops below
the low temperature limit set by the TLOW Limit Register for the appropriate number of consecutive faults. Again, the
ALERT pin will remain active until one of the device's registers is read, the device responds to an SMBus ARA, or the
device is placed into the Shutdown mode.
After the ALERT pin becomes inactive again, the cycle will repeat itself with the ALERT pin going active after the
measured temperature meets or exceeds the THIGH Limit Register value for the proper number of consecutive faults. This
process is cyclical between THIGH and TLOW temperature alarms (e.g. THIGH event, ALERT clear, TLOW event, ALERT
clear, THIGH event, ALERT clear, TLOW event, etc.).
In order for the ALERT pin to normally become active for the first time in the Interrupt Mode, the first event must be a
THIGH temperature alarm event; therefore, even if the measured temperature initially starts off between the THIGH and
TLOW limits and then drops below the TLOW temperature limit and has met valid fault conditions, the ALERT pin will still not
go active. The high temperature limit set by the THIGH Limit Register must be greater than the low temperature limit set by
the TLOW Limit Register in order for the ALERT pin to activate correctly.
If switching from Comparator mode to Interrupt Mode while the ALERT pin is already active, then the ALERT pin will
remain active until it is cleared by one of the events already detailed: any one of the device's registers is read, the device
responds to an SMBus Alert Response Address (ARA), or the device is put into Shutdown Mode. The ALERT pin will
also return to the inactive state if the device receives the General Call Reset command. When reset, the contents of the
Nonvolatile Configuration Register will be copied into the Configuration Register; therefore, the device may or may not
return to the Interrupt mode depending on the setting of the NVCMP/INT bit in the Nonvolatile Configuration Register.
Figures 5-3 and Figure 5-4 show both the active high and active low ALERT pin response for a sample temperature
profile with the device configured for the Interrupt mode and a fault tolerance queue setting of two. Figure 5-4 illustrates
how the ALERT pin output would look if there was a longer delay between the ALERT trigger and the reading of a
register.
Figure 5-3. Interrupt Mode (Fault Tolerance Queue = 2)
Temperature Measurements/Conversions
THIGH Limit
Temperature
TLOW Limit
ALERT
(Active High, POL = 1)
ALERT
(Active Low, POL = 0)
Read Register Read Register Read Register
13
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
Figure 5-4. Interrupt Mode (Fault Tolerance Queue = 2) Delay Before Reading Register
5.3 Shutdown Mode
To reduce current consumption and save power, the device features a Shutdown mode that disables all internal device
circuitry except for the serial interface and POR circuits. While in the Shutdown mode, the internal temperature sensor is
not active, so no temperature measurements will be made. Entering and exiting the Shutdown mode is controlled by the
SD bit in the Configuration Register.
Entering the Shutdown mode can affect the ALERT pin depending on the Alarm Thermostat mode. If the device is
configured to operate in the Interrupt mode, then the ALERT pin will go inactive when the device enters the Shutdown
mode; however, the ALERT pin will not change states if the device is operating in the Comparator mode.
The fault count information will not change when the device enters or exits the Shutdown mode; therefore, the number of
previous temperature faults recorded by the internal fault counter will be retained unless the device is power-cycled or
reset. When exiting the Shutdown mode, the ALERT pin will go active if operating in Interrupt mode, a valid fault
condition exists, and the THIGH and TLOW event cycles are maintained (i.e. THIGH event before entering Shutdown mode
followed by a TLOW event when exiting Shutdown mode).
The device can be powered-down while in the Shutdown mode so that it will remain in the Shutdown mode after the
subsequent Power-up operation. This is accomplished by setting the NVSD bit in the Nonvolatile Configuration Register
to the Logic 1 state prior to power-down. Upon power-up or reset, the device will first copy the contents of the Nonvolatile
Data Registers into the Volatile Data Registers, after which the device will perform a single temperature measurement
and store the result in the Temperature Register. After this process is complete, the device will re-enter the Shutdown
mode.
5.3.1 One-Shot Mode
The AT30TS750A features a One-Shot Temperature mode that allows the device to perform a single temperature
measurement while in the Shutdown mode. By keeping the device in the Shutdown mode and utilizing the One-Shot
mode, the AT30TS750A can remain in a lower power state and only go active to take temperature measurements on an
as-needed basis. The internal fault counter will be updated when taking a temperature measurement using the
One-Shot mode; therefore, a valid fault condition can be generated by the One-Shot temperature measurements. If
operating in Comparator mode, then the fault condition will cause the ALERT pin to go either active or inactive depending
on if the fault condition is a result of a THIGH or TLOW event. If operating in Interrupt mode, the fault condition will cause the
ALERT pin to pulse active for a short duration of time to indicate a THIGH or TLOW event has occurred. The ALERT pin will
then return to the inactive state.
The One-Shot mode is controlled using the OS bit in the Configuration Register (see Section 6.3.1, “OS Bit” on page 19).
Temperature Measurements/Conversions
THIGH Limit
Temperature
TLOW Limit
ALERT
(Active High, POL = 1)
ALERT
(Active Low, POL = 0)
Read Register Read Register
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
14
6. Registers
The AT30TS750A contains eight registers (a Pointer Register and seven data registers) that are used to control the
operational mode and performance of the temperature sensor, store the user-defined high and low temperature limits,
and store the digitized temperature measurements. All accesses to the device are performed using these eight registers.
In order to read from and write to one of the device's seven data registers, the user must first select a desired data
register by utilizing the Pointer Register.
The device incorporates both volatile and nonvolatile versions of the Configuration Register, the TLOW Limit Register, and
the THIGH Limit Register. Upon device power-up or reset, the AT30TS750A will copy the contents of the Nonvolatile Data
Registers into the Volatile Data Registers. Both the volatile and Nonvolatile Data Registers can be modified separately
provided that the registers are not locked or locked down; however, all temperature sensor related operations, such as
responses to high and low temperature conditions, are based on the settings stored in the volatile versions of the
registers only. Therefore, if the Nonvolatile Data Registers are updated with new values, then the contents of the
Nonvolatile Data Registers should be copied to the Volatile Data Registers (see Section 9.1, “Copy Nonvolatile Registers
to Volatile Registers” on page 32)
Table 6-1. Registers
The Configuration Register, despite being 16-bits wide, is compatible to industry standard LM75-type temperature
sensors that use an 8-bit wide register in that only the first 8-bits of the Configuration Register need to be written to or
read from.
6.1 Pointer Register
The 8-bit Write-Only Pointer Register is used to address and select which one of the device's seven data registers
(Temperature Register, Configuration Register, TLOW Limit Register, THIGH Limit Register, Nonvolatile Configuration
Register, Nonvolatile TLOW Limit Register, or Nonvolatile THIGH Limit Register) will be read from or written to.
For Read operations from the AT30TS750A, once the Pointer Register is set to point to a particular data register, it
remains pointed to that same data register until the Pointer Register value is changed.
Example: If the user sets the Pointer Register to point to the Temperature Register, then all subsequent reads from
the device will output data from the Temperature Register until the Pointer Register value is changed.
Register Address Read/Write Size Power-on Default
Factory
Default
Pointer Register n/a W 8-bit 00h n/a
Temperature Register 00h R 16-bit 0000h n/a
Configuration Register 01h R/W 16-bit Copy of Nonvolatile Configuration
Register n/a
TLOW Limit Register 02h R/W 16-bit Copy of Nonvolatile TLOW Limit Register n/a
THIGH Limit Register 03h R/W 16-bit Copy of Nonvolatile THIGH Limit Register n/a
Nonvolatile Configuration Register 11h R/W 16-bit Last Programmed State 0000h
Nonvolatile TLOW Limit Register 12h R/W 16-bit Last Programmed State 4B00h (75C)
Nonvolatile THIGH Limit Register 13h R/W 16-bit Last Programmed State 5000h (80C)
15
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
For Write operations to the AT30TS750A, the Pointer Register value must be refreshed each time a write to the device is
to be performed, even if the same data register is going to be written to a second time in a row.
Example: If the Pointer Register is set to point to the Configuration Register, once the subsequent Write operation to
the Configuration Register has completed, the user cannot write again into the Configuration Register
without first setting the Pointer Register value again. As long as a Write operation is to be performed, the
device will assume that the Pointer Register value is the first data byte received after the address byte.
Since only seven data registers are available for access, only the five LSBs (P4-P0) of the Pointer Register are used; the
remaining three bits (P7-P5) of the Pointer Register should always be set to zero to allow for future migration paths to
other temperature sensor devices that have more than seven data registers. In addition, the device incorporates
additional commands that are decoded in lieu of the Pointer Register byte; therefore, if bits P7-P5 are not set as zero
when setting the value of the Pointer Register byte, the device may interpret the data as one of the additional commands.
Table 6-2 shows the bit assignments of the Pointer Register and the associated pointer addresses of the data registers
available. Attempts to write any values other than those listed in Table 6-2 into the Pointer Register will be ignored by the
device, and the contents of the Pointer Register will not be changed. The device will respond back to the Master with a
NACK to indicate that the device received an invalid Pointer Register byte.
Table 6-2. Pointer Register and Address Assignments
To set the value of the Pointer Register, the Master must first initiate a Start condition followed by the AT30TS750A
device address byte (1001AAA0 where “AAA” corresponds to the hard-wired A2-0 address pins). After the AT30TS750A
has received the proper address byte, the device will send an ACK to the Master. The Master must then send the
appropriate data byte to the AT30TS750A to set the value of the Pointer Register.
After device power-up or reset, the Pointer Register defaults to 00h which is the Temperature Register location;
therefore, the Temperature Register can be read from immediately after device power-up or reset without having to set
the Pointer Register. If the device is configured to power-up in the Shutdown mode, then the device will make a single
temperature measurement immediately after power-up so that valid temperature data can be output from the
Temperature Register.
Figure 6-1. Write Pointer Register
Pointer Register Value Associated
Address Register SelectedP7 P6 P5 P4 P3 P2 P1 P0
0 0 0 0 0 0 0 0 00h Temperature Register
0 0 0 0 0 0 0 1 01h Configuration Register
00000010 02h TLOW Limit Register
00000011 03h THIGH Limit Register
00010001 11h Nonvolatile Configuration Register
00010010 12h Nonvolatile TLOW Limit Register
00010011 13h Nonvolatile THIGH Limit Register
SCK
SDA
Address Byte Pointer Register Byte
Start
by
Master
ACK
from
Slave
MSB MSB
ACK
from
Slave
Stop
by
Master
1 0 0 1 A A A 0 0 P7 P6 P5 P4 P3 P2 P1 P0 0
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
16
6.2 Temperature Register
The Temperature Register is a 16-bit Read-only Register that stores the digitized value of the most recent temperature
measurement. The temperature data value is represented in the twos complement format, and, depending on the
resolution selected, up to 12 bits of data will be available for output with the remaining LSBs being fixed in the Logic 0
state. The Temperature Register can be read at any time, and since temperature measurements are performed in the
background, reading the Temperature Register does not affect any other operation that may be in progress.
The MSB (bit 15) of the Temperature Register contains the sign bit of the measured temperature value with a zero
indicating a positive number and a one indicating a negative number. The remaining MSBs of the Temperature Register
contain the temperature value in the twos complement format. Table 6-3 details the Temperature Register format for the
different selectable resolutions, and Table 6-4 shows some examples for 12-bit resolution Temperature Register data
values and the associated temperature readings.
Table 6-3. Temperature Register Format
Note: TD = Temperature Data
Table 6-4. 12-bit Resolution Temperature Data/Values Examples
Resolution
Upper Byte Lower Byte
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
12 bits Sign TD TD TD TD TD TD TD TD TD TD TD 0 0 0 0
11 bits Sign TD TD TD TD TD TD TD TD TD TD 0 0 0 0 0
10 bits Sign TD TD TD TD TD TD TD TD TD 0 0 0 0 0 0
9 bits Sign TD TD TD TD TD TD TD TD 0 0 0 0 0 0 0
Temperature
Temperature Register Data
Binary Value Hex Value
+125°C 0111 1101 0000 0000 7D00h
+100°C 0110 0100 0000 0000 6400h
+75°C 0100 1011 0000 0000 4B00h
+50.5°C 0011 0010 1000 0000 3280h
+25.25°C 0001 1001 0100 0000 1940h
+10.125°C 0000 1010 0010 0000 0A20h
+0.0625°C 0000 0000 0001 0000 0010h
0°C 0000 0000 0000 0000 0000h
-0.0625°C 1111 1111 1111 0000 FFF0h
-10.125°C 1111 0101 1110 0000 F5E0h
-25.25°C 1110 0110 1100 0000 E6C0h
-50.5°C 1100 1101 1000 0000 CD80h
-55°C 1100 1001 0000 0000 C900h
17
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
After each temperature measurement and digital conversion is complete, the new temperature data is loaded into the
Temperature Register if the register is not currently being read. If a Read is in progress, then the previous temperature
data will be output.
In order to read the most recent temperature measurement data, the Pointer Register must be set or have been
previously set to 00h. If the Pointer Register has already been set to 00h, the Temperature Register can be read by
having the Master first initiate a Start condition followed by the AT30TS750A device address byte (1001AAA1 where
“AAA” corresponds to the hard-wired A2-0 address pins). After the AT30TS750A has received the proper address byte,
the device will send an ACK to the Master. The Master can then read the upper byte of the Temperature Register. After
the upper byte of the Temperature Register has been clocked out of the AT30TS750A, the Master must send an ACK to
indicate that it is ready for the lower byte of the temperature data. The AT30TS750A will then clock out the lower byte of
the Temperature Register, after which the Master must send a NACK to end the operation. When the AT30TS750A
receives the NACK, it will release the SDA line so that the Master can send a Stop or repeated Start condition. If the
Master does not send a NACK but instead sends an ACK after the lower byte of the Temperature Register has been
clocked out, then the device will repeat the sequence by outputting new temperature data starting with the upper byte of
the Temperature Register.
If 8-bit temperature resolution is satisfactory, then the lower byte of the Temperature Register does not need to be read.
In this case, the Master would send a NACK instead of an ACK after the upper byte of the Temperature Register has
been clocked out of the AT30TS750A. When the AT30TS750A receives the NACK, the device will know that it should not
send out the lower byte of the Temperature Register and will instead release the SDA line so the Master can send a Stop
or repeated Start condition.
The Temperature Register defaults to 0000h after device power-up or reset; therefore, the system should wait the
maximum conversion time (tCONV) for the selected resolution before attempting to read valid temperature data. If the
device is configured to power-up in the Shutdown mode, then the device will make a single temperature measurement
immediately after power-up so that valid temperature data can be output from the Temperature Register after the
maximum tCONV time. Since the Temperature Register is a Read-only register, any attempts to write to the register will be
ignored, and the device will subsequently respond by sending a NACK back to the Master for any data bytes that are
sent.
Figure 6-2. Read Temperature Register — 16 Bits
Note: Assumes the Pointer Register was previously set to point to the Temperature Register.
Figure 6-3. Read Temperature Register — 8 Bits
Note: Assumes the Pointer Register was previously set to point to the Temperature Register.
SCK
SDA
Address Byte Temperature Register Upper Byte Temperature Register Lower Byte
Start
by
Master
ACK
from
Slave
ACK
from
Master
MSB MSB
NACK
from
Master
Stop
by
Master
MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 0 1 A A A 1 0 D15 D14 D13 D12 D11 D10 D9 D8 0 D7 D6 D5 D4 D3 D2 D1 D0 1
SCK
SDA
Address Byte Temperature Register Upper Byte
Start
by
Master
ACK
from
Slave
MSB MSB
NACK
from
Master
Stop
by
Master
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 0 1 A A A 1 0 D15 D14 D13 D12 D11 D10 D9 D8 1
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
18
6.3 Configuration Register
The Configuration Register is used to control key operational modes and settings of the device such as the One-Shot
mode, the temperature conversion resolution, the fault tolerance queue, the ALERT pin polarity, the Alarm Thermostat
mode, and the Shutdown mode. The Configuration Register is a 16-bit wide Read/Write Register; however, only the first
8-bits of the register are actually used while the least-significant 8-bits are reserved for future use to provide an upward
migration path to other temperature sensor devices that have enhanced features. Since only the most-significant 8-bits of
the Configuration Register are used, the device is backwards compatible to industry standard LM75-type temperature
sensors that use 8-bit wide registers.
After device power-up or reset, the contents of the most-significant byte (bits 15 through 8) of the Nonvolatile
Configuration Register will always be automatically copied into the Configuration Register; therefore, the Configuration
Register settings will match the settings of the Nonvolatile Configuration Register prior to when the device was powered-
down or reset. Since the Configuration Register value will always be copied from the Nonvolatile Configuration Register,
the Configuration Register can be temporarily changed without affecting subsequent power-up/reset settings. If it is
desired for the new Configuration Register settings to become the new power-up/reset settings, then the contents of the
Configuration Register can be copied into the most-significant byte of the Nonvolatile Configuration Register by using the
copy Volatile Registers to Nonvolatile Registers command (see Section 9.2, “Copy Volatile Registers to Nonvolatile
Registers” on page 33).
Note: When using the copy Volatile Registers to Nonvolatile Registers command, the contents of the THIGH and
TLOW Limit Registers will also be copied into the nonvolatile THIGH and TLOW Limit Registers.
Table 6-5. Configuration Register
Bit Name Type Description
15 OS One-Shot Mode R/W
0 Normal Operation (Default)
1Perform One-Shot Measurement (Valid in Shutdown Mode Only)
14:13 R1:R0 Conversion Resolution R/W
00 9-bits (Default)
01 10-bits
10 11-bits
11 12-bits
12:11 FT1:FT0 Fault Tolerance Queue R/W
00 Alarm after 1 Fault (Default)
01 Alarm after 2 Consecutive Faults
10 Alarm after 4 Consecutive Faults
11 Alarm after 6 Consecutive Faults
10 POL ALERT Pin Polarity R/W
0ALERT Pin is Active Low (Default)
1ALERT Pin is Active High
9 CMP/INT Alarm Thermostat Mode R/W
0 Comparator Mode (Default)
1 Interrupt Mode
8 SD Shutdown Mode R/W
0Temperature Sensor Performing Active Measurements (Default)
1 Temperature Sensor Disabled and Device In Shutdown Mode
7:1 RFU Reserved for Future
Use R0Reserved for Future Use
0 NVRBSY Nonvolatile Registers
Busy R
0 Nonvolatile Registers are ready for access.
1 Nonvolatile Registers are busy and cannot be read from or
written to.
19
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
To set the value of the Configuration Register, the Master must first initiate a Start condition followed by the
AT30TS750A's device address byte (1001AAA0 where “AAA” corresponds to the hard-wired A2-0 address pins). After the
AT30TS750A has received the proper address byte, the device will send an ACK to the Master. The Master must then
send the appropriate Pointer Register byte of 01h to select the Configuration Register. After the Pointer Register byte of
01h has been sent, the AT30TS750A will send another ACK to the Master. After receiving the ACK from the
AT30TS750A, the Master must then send the appropriate data byte to the AT30TS750A to set the value of the
Configuration Register. Only the first data byte sent to the AT30TS750A will be recognized as valid data; any subsequent
bytes received by the device will simply be ignored. If the Master does not send a complete byte of Configuration
Register data prior to issuing a Stop or repeated Start condition, then the AT30TS750A will ignore the data and the
contents of the Configuration Register will be unchanged.
In addition to the Master not sending a complete byte of Configuration Register data, writing to the Configuration Register
will be ignored and no operation will be performed if the Volatile and Nonvolatile Registers are currently locked (the
RLCK bit of the Nonvolatile Configuration Register is in the Logic 1 state) or the Volatile and Nonvolatile Registers are
permanently locked down (the RLCKDWN bit of the Nonvolatile Configuration Register is in the Logic 1 state). However,
the device will still respond with an ACK to indicate that it received the proper data byte even though the contents of the
Configuration Register will not be changed.
6.3.1 OS Bit
The OS bit is used to enable the One-Shot Temperature Measurement mode. When a Logic 1 is written to the OS bit
while the AT30TS750A is in the Shutdown mode, the device will become active and perform a single temperature
measurement and conversion. After the Temperature Register has been updated with the measured temperature data,
the device will return to the low-power Shutdown mode and clear the OS bit.
Writing a one to the OS bit when the device is not in the Shutdown mode will have no affect. When reading the
Configuration Register, the OS bit will always be read as a Logic 0.
6.3.2 R1:R0 Bits
The R1 and R0 bits are used to select the conversion resolution of the internal sigma-delta ADC. Four possible
resolutions can be set to maximize for either higher resolution or faster conversion times. The R1 and R0 bits will be
copied from the NVR1 and NVR0 in the Nonvolatile Configuration Register after device power-up or reset, allowing the
device to retain the conversion resolution that was previously set by the Nonvolatile Configuration Register prior to
power-down or reset.
Table 6-6. Conversion Resolution
R1 R0 Conversion Resolution Conversion Time
0 0 9 bits 0.5°C 25ms
0 1 10 bits 0.25°C 50ms
1 0 11 bits 0.125°C 100ms
1 1 12 bits 0.0625°C 200ms
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
20
6.3.3 FT1:FT0 Bits
The FT1 and FT0 bits are used to set the fault tolerance queue value which defines how many consecutive faults must
occur before the ALERT pin will be activated (see Section 5.2.1, “Fault Tolerance Limits” on page 10). The FT1 and FT0
bit settings provide four different fault values as detailed in Table 6-7. After the device powers up or resets, the FT1 and
FT0 bits will be copied from the NVFT1 and NVFT0 in the Nonvolatile Configuration Register; therefore, the fault
tolerance queue value will default to whatever value was previously stored in the Nonvolatile Configuration Register prior
to Configuration Register power-down or reset.
Table 6-7. Fault Tolerance Queue
6.3.4 POL Bit
The ALERT pin polarity is controlled by the POL bit. When the POL bit is in the Logic 0 state, the ALERT pin will be an
active low output. To configure the ALERT pin as an active high output, the POL bit must be set to the Logic 1 state.
After the device powers up or resets, the POL bit will be copied from the NVPOL bit in the Nonvolatile Configuration
Register; therefore, the polarity of the ALERT pin will default to the state defined by the Nonvolatile Configuration
Register prior to power-down or reset.
6.3.5 CMP/INT Bit
The CMP/INT bit controls whether the device will operate in the Comparator mode or the Interrupt mode. Setting the
CMP/INT bit to the Logic 0 state will put the device into the Comparator mode. Alternatively, when the CMP/INT bit is set
to the Logic 1 state, then the device will operate in the Interrupt mode. The function of the ALERT pin changes based on
the CMP/INT bit setting.
The CMP/INT bit will be copied from the NVCMP/INT bit in the Nonvolatile Configuration Register after the device powers
up or resets. Since the CMP/INT bit is copied from the NVCMP/INT bit, the device will default to whatever mode was
selected by the Nonvolatile Configuration Register prior to power-down or reset.
6.3.6 SD Bit
The SD bit is used to enable or disable the device's Shutdown mode. When the SD bit is in the Logic 0 state, the device
will be in the normal operational mode and perform continuous temperature measurements and conversions. When the
SD bit is set to the Logic 1 state, the device will finish the current temperature measurement and conversion and will
store the result in the Temperature Register, after which the device will then enter the Shutdown mode.
Resetting the SD bit back to a Logic 0 will return the device to the normal operating mode.
After the device powers up or resets, the SD bit will be copied from the NVSD bit in the Nonvolatile Configuration
Register; therefore, it is possible for the device to automatically enter the Shutdown mode after power-up or reset by
setting the NVSD bit to the Logic 1 state prior to power-down or reset. See Section 5.3, “Shutdown Mode” on page 13 for
more details.
FT1 FT0 Consecutive Faults Required
0 0 1
0 1 2
1 0 4
1 1 6
21
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
6.3.7 NVRBSY
The Ready/Busy status of the Nonvolatile Configuration Register, Nonvolatile TLOW Limit Register, and Nonvolatile THIGH
Limit Register can be determined by reading the NVRBSY bit. When the NVRBSY bit is in the Logic 0 state, then the
Nonvolatile Configuration and Limit Registers are available to be read from or written to. When the NVRBSY bit is in the
Logic 1 state, the Nonvolatile Registers are busy and cannot be accessed for reading, writing, or copying. Attempting to
read the Nonvolatile Registers while the registers are busy will result in erroneous data being output. Similarly, any
attempts to write to one of the Nonvolatile Registers while the NVRBSY bit is in the Logic 1 state will result in the data
being ignored. Both the copy Nonvolatile Registers to Volatile Registers and the copy Volatile Registers to Nonvolatile
Registers commands will also be ignored when the NVRBSY bit is in the Logic 1 state. For more details and a complete
list of commands that are and are not allowed while NVRBSY is in the Logic 1 state, see Section 8., “Operations Allowed
During Nonvolatile Busy Status” on page 31.
Figure 6-4. Write to Configuration Register
Figure 6-5. Read from Configuration Register
Note: Assumes the Pointer Register was previously set to point to the Configuration Register.
SCK
SDA
Address Byte Pointer Register Byte Configuration Register Upper Byte
Start
by
Master
ACK
from
Slave
ACK
from
Slave
MSB MSB
ACK
from
Slave
Stop
by
Master
MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 0 1 A A A 0 0 0 0 0 0 0 0 0 1 0 D15 D14 D13 D12 D11 D10 D9 D8 0
SCK
SDA
Start
by
Master
ACK
from
Slave
NACK
from
Master
Address Byte Configuration Register Upper Byte
Stop
by
Master
MSB MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 0 1 A A A 1 0 D15 D14 D13 D12 D11 D10 D9 D8 1
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
22
6.4 Nonvolatile Configuration Register
The Nonvolatile Configuration Register is a 16-bit wide Read/Write register used to manage key power-up/reset device
settings and operational modes including the locking of the AT30TS750A's various registers. The Nonvolatile
Configuration Register is used in conjunction with the Configuration Register to control how the device operates. All bits
in the Nonvolatile Configuration Register will retain their state even after the device has been powered down or reset. On
every power-up or reset sequence, the contents of the most-significant byte (bits 15 through 8) of the Nonvolatile
Configuration Register will be copied into the Configuration Register, after which all device operations and settings will
then be controlled by the Configuration Register. By utilizing the Nonvolatile Configuration Register, the device can
power-up or reset in a pre-defined, user-selected operating mode (e.g. Comparator mode, Shutdown mode, etc.) with
pre-defined settings (e.g. 12-bit resolution, ALERT pin active high, etc.); therefore, unlike standard LM75-type
temperature sensors, there is no need to update the Configuration Register settings after every power-up or reset.
Since the Nonvolatile Configuration Register utilizes nonvolatile storage cells, care must be taken when updating the
register to accommodate the aspects of an associated program time and finite program endurance limit. Power must not
be removed from the device during the internally self-timed programming cycle of the register. If power is removed prior
to the completion of the programming cycle, then the contents of the register cannot be guaranteed. In addition, the
contents of the register may become corrupt if it is programmed more than the maximum allowed number of writes.
Table 6-8. Nonvolatile Configuration Register
Bit Name Type Description
15 NU Not Used R 0Not Used.
14:13 NVR1:NVR0 Conversion Resolution R/W
00 9-bits (Factory Default)
01 10-bits
10 11-bits
11 12-bits
12:11 NVFT1:NVFT0 Fault Tolerance Queue R/W
00 Alarm after 1 Fault (Factory Default).
01 Alarm after 2 Consecutive Faults.
10 Alarm after 4 Consecutive Faults.
11 Alarm after 6 Consecutive Faults.
10 NVPOL ALERT Pin Polarity R/W 0ALERT Pin is Active Low (Factory Default).
1ALERT Pin is Active High.
9 NVCMP/INT Alarm Thermostat Mode R/W 0 Comparator Mode (Factory Default).
1 Interrupt Mode.
8 NVSD Shutdown Mode R/W
0Temperature Sensor Performing Active Measurements
(Factory Default).
1Temperature Sensor Disabled and Device in Shutdown
Mode.
7:3 RFU Reserved for Future Use 0Reserved for Future Use.
2 RLCKDWN Register Lockdown R/W
0All Configuration and Limit Registers are Not Locked Down
(Factory Default).
1All Configuration and Limit Registers are permanently
locked down (ROM) and can never be modified again.
1 RLCK Register Lock R/W
0All Configuration and Limit Registers are unlocked and can
be modified (Factory Default).
1all configuration and Limit Registers are locked and cannot
be modified.
0 RFU Reserved for Future Use R0Reserved for Future Use.
23
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
To set the value of the Nonvolatile Configuration Register, the Master must first initiate a Start condition followed by the
AT30TS750A device address byte (1001AAA0 where “AAA” corresponds to the hard-wired A2-0 address pins). After the
AT30TS750A has received the proper address byte, the device will send an ACK to the Master. The Master must then
send the appropriate Pointer Register byte of 11h to select the Nonvolatile Configuration Register. After the Pointer
Register byte of 11h has been sent, the AT30TS750A will send another ACK to the Master. After receiving the ACK from
the AT30TS750A, the Master must then send two data bytes to the AT30TS750A to set the value of the Nonvolatile
Configuration Register. Any subsequent bytes sent to the AT30TS750A will simply be ignored by the device. If the
Master does not send two complete bytes of Nonvolatile Configuration Register data prior to issuing a Stop or repeated
Start condition, then the AT30TS750A will ignore the data and the contents of the Nonvolatile Configuration Register will
not be changed.
After the Master has issued a Stop or repeated Start condition, the AT30TS750A will begin the internally self-timed
program operation, and the contents of the Nonvolatile Configuration Register will be updated within a time of tPROG.
During this time, the NVRBSY bit in the Configuration Register will indicate that the device is busy. If the Master issues a
repeated Start condition instead of a Stop condition, the AT30TS750A will abort the operation and the contents of the
Nonvolatile Configuration Register will not be changed.
In addition to the Master not sending two complete bytes of data, writing to the Nonvolatile Configuration Register will be
ignored and no operation will be performed under the following conditions: the Nonvolatile Registers are already busy
(the NVRBSY bit of the Configuration Register is in the Logic 1 state), the Volatile and Nonvolatile Registers are currently
locked (the RLCK bit of the Nonvolatile Configuration Register is in the Logic 1 state), or the Volatile and Nonvolatile
Registers are permanently locked down (the RLCKDWN bit of the Nonvolatile Configuration Register is in the Logic 1
state). However, the device will still respond with an ACK, except in the case of the Nonvolatile Registers being busy, to
indicate that it received the proper data bytes even though the program operation will not be performed. In the case of the
Nonvolatile Registers being busy, the device will respond with an ACK to the address and pointer bytes but will then
NACK when the data bytes are sent from the Master.
6.4.1 NVR1: NVR0 Bits
The nonvolatile NVR1 and NVR0 bits are used to select the power-up/reset default conversion resolution of the internal
sigma-delta ADC. Four possible resolutions can be set to maximize for either higher resolution or faster conversion
times. The NVR1 and NVR0 bits are set from the factory to default to the Logic 0 state to retain backwards compatibility
to industry-standard LM75-type devices.
Table 6-9. Conversion Resolution
NVR1 NVR0 Conversion Resolution Conversion Time
0 0 9 bits 0.5°C 25ms
0 1 10 bits 0.25°C 50ms
1 0 11 bits 0.125°C 100ms
1 1 12 bits 0.0625°C 200ms
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
24
6.4.2 NVFT1:NVFT0 Bits
The nonvolatile NVFT1 and NVFT0 bits are used to set the power-up/reset default Fault Tolerance Queue value which
defines how many consecutive faults must occur before the ALERT pin will be activated (see Section 5.2.1, “Fault
Tolerance Limits” on page 10). The NVFT1 and NVFT0 bit settings provide four different fault values as detailed in Table
6-10. Both the NVFT1 and NVFT0 bits are factory-set to default to the Logic 0 state.
Table 6-10. Fault Tolerance Queue
6.4.3 NVPOL Bit
The nonvolatile NVPOL bit controls the power-up/reset default ALERT pin polarity. When the NVPOL bit is set to the
Logic 0 state, the ALERT pin will be an active low output after the device powers up or resets. Conversely, when the
NVPOL bit is set to the Logic 1 state, the ALERT pin will be an active high output. The NVPOL bit is set from the factory
to default to the Logic 0 state.
6.4.4 NVCMP/INT Bit
The nonvolatile NVCMP/INT bit controls whether the device will operate in the Comparator mode or the Interrupt mode
after a power-up or reset sequence. Setting the NVCMP/INT bit to the Logic 0 state (the factory default setting) will allow
the device to power-up/reset in the Comparator mode. Alternatively, when the NVCMP/INT bit is set to the Logic 1 state,
the device will power-up/reset in the Interrupt mode.
6.4.5 NVSD Bit
The nonvolatile NVSD bit is used to enable the device to power-up/reset in the Shutdown mode. When the NVSD bit is in
the Logic 0 state, the device will power-up/reset in the normal operational mode and perform continuous temperature
measurements and conversions. When the NVSD bit is set to the Logic 1 state, the device will automatically enter the
Shutdown mode after a power-up or reset sequence (see Section 5.3, “Shutdown Mode” on page 13 for more details).
The NVSD bit is factory-set to the Logic 0 state.
6.4.6 RLCKDWN
The one-time programmable RLCKDWN bit controls whether or not both the volatile and nonvolatile versions of the
configuration and limit registers will be permanently locked down. Once the RLCKDWN bit is set to the Logic 1 state, the
Configuration Register, TLOW Limit Register, THIGH Limit Register, Nonvolatile Configuration Register, Nonvolatile TLOW
Limit Register, and Nonvolatile THIGH Limit Register will be locked down and can never be modified again. Since the
RLCKDWN bit is one-time programmable, once the bit is set to the Logic 1 state, it cannot be reset again. The
RLCKDWN bit takes priority over the RLCK bit (see Section 7., “Register Locking” on page 30 for more details) and is
factory-set to the Logic 0 state.
NVFT1 NVFT0 Consecutive Faults Required
0 0 1
0 1 2
1 0 4
1 1 6
25
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
6.4.7 RLCK
The nonvolatile RLCK bit controls the reversible locking of both the Volatile and Nonvolatile Configuration and Limit
Registers. When the RLCK bit is set to the Logic 0 state, the Configuration Register, TLOW Limit Register, THIGH Limit
Register, Nonvolatile Configuration Register, Nonvolatile TLOW Limit Register, and Nonvolatile THIGH Limit Register will be
unlocked and can be modified. Alternatively, when the RLCK bit is set to the Logic 1 state, the Volatile and Nonvolatile
Configuration and Limit Registers will be locked and cannot be modified. When the registers are locked, only the RLCK
bit of the Nonvolatile Configuration Register can be altered and reset back to a Logic 0. Any attempts at changing other
bits in the Nonvolatile Configuration Register will be ignored. The RLCK bit is set from the factory to default to the
Logic 0 state. See Section 7., “Register Locking” on page 30 for more details.
Figure 6-6. Write to Nonvolatile Configuration Register
Figure 6-7. Read from Nonvolatile Configuration Register
Note: Assumes the Pointer Register was previously set to point to the Nonvolatile Configuration Register.
SCL
SDA
Start
by
Master
ACK
from
Slave
ACK
from
Slave
Address Byte
Nonvolatile Configuration Register
Upper Byte
Nonvolatile Configuration Register
Lower Byte
Pointer Register Byte
MSB MSB
ACK
from
Slave
ACK
from
Slave
Stop
by
Master
MSB MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 0 1 A A A 0 0 0 0 0 1 0 0 0 1 0
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
D15 D14 D13 D12 D11 D10 D9 D8 0 D7 D6 D5 D4 D3 D2 D1 D0 0
SCL
SDA
Start
by
Master
ACK
from
Slave
NACK
from
Master
Stop
by
Master
ACK
from
Master
Address Byte
Nonvolatile Configuration Register
Upper Byte
Nonvolatile Configuration Register
Lower Byte
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 0 1 A A A 1 0 D15 D14 D13 D12 D11 D10 D9 D8 0 D7 D6 D5 D4 D3 D2 D1 D0 1
MSB MSB MSB
AT30TS750A [DATASHEET]
Atmel-8855F-DTS-AT30TS750A-Datasheet_102014
26
6.5 TLOW and THIGH Limit Registers
The 16-bit TLOW and THIGH Limit Registers store the user-programmable lower and upper temperature limits for the
temperature alarm. Like the Temperature Register, the temperature data values of the TLOW and THIGH Limit Registers
are stored in the twos complement format with the MSB (bit 15) of the registers containing the sign bit (zero indicates a
positive number and a one indicates a negative number).
As with the Temperature Register, the resolution selected by the R1 and R0 bits of the Configuration Register will
determine how many bits of the TLOW and THIGH Limit Registers will be used; therefore, when writing to the TLOW and
THIGH Limit Registers, up to 12 bits of data will be recognized by the device with the remaining LSBs being internally fixed
to the Logic 0 state. Similarly, when reading from the registers, up to 12 bits of data will be output from the device with the
remaining LSBs fixed in the Logic 0 state.
Table 6-11. TLOW Limit Register and THIGH Limit Register Format
Note: TD = Temperature Data
To set the value of either the TLOW or THIGH Limit Register, the Master must first initiate a Start condition followed by the
AT30TS750A device address byte (1001AAA0 where “AAA” corresponds to the hard-wired A2-0 address pins). After the
AT30TS750A has received the proper address byte, the device will send an ACK to the Master. The Master must then
send the appropriate Pointer Register byte of 02h to select the TLOW Limit Register or 03h to select the THIGH Limit
Register. After the Pointer Register byte has been sent, the AT30TS750A will send another ACK to the Master. After
receiving the ACK from the AT30TS750A, the Master must then send two data bytes to the AT30TS750A to set the value
of the TLOW or THIGH Limit Register. Any subsequent bytes sent to the AT30TS750A will simply be ignored by the device.
If the Master does not send two complete bytes of data prior to issuing a Stop or repeated Start condition, then the
AT30TS750A will ignore the data and the contents of the register will not be changed.
In addition to the Master not sending two complete bytes of data, writing to the TLOW or THIGH Limit Register will be
ignored and no operation will be performed under the following conditions: the Nonvolatile Registers are busy because of
a copy operation (the NVRBSY bit of the Configuration Register is in the Logic 1 state), the Volatile and Nonvolatile
Registers are currently locked (the RLCK bit of the Nonvolatile Configuration Register is in the Logic 1 state), or the
Volatile and Nonvolatile Registers are permanently locked down (the RLCKDWN bit of the Nonvolatile Configuration
Register is in the Logic 1 state). However, the device will still respond with an ACK, except in the case of the Nonvolatile
Registers being busy, to indicate that it received the proper data bytes even though the contents of the TLOW or THIGH
Limit Register will not be changed. In the case of the Nonvolatile Registers being busy, the device will respond with an
ACK to the address and pointer bytes but will then NACK when the data bytes are sent from the Master.
In order to read the TLOW or THIGH Limit Register, the Pointer Register must be set or have been previously set to 02h to
select the TLOW Limit Register or 03h to select the THIGH Limit Register (if the previous operation was a Write to one of the
registers, then the Pointer Register will already be set for that particular limit register). If the Pointer Register has already
been set appropriately, the TLOW or THIGH Limit Register can be read by having the Master first initiate a Start condition
followed by the AT30TS750A device address byte (1001AAA1 where “AAA” corresponds to the hard-wired A2-0 address
pins). After the AT30TS750A has received the proper address byte, the device will send an ACK to the Master. The
Master can then read the upper byte of the TLOW or THIGH Limit Register. After the upper byte of the register has been
clocked out of the AT30TS750A, the Master must send an ACK to indicate that it is ready for the lower byte of data. The
AT30TS750A will then clock out the lower byte of the register, after which the Master must send a NACK to end the
Resolution
Upper Byte Lower Byte
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
12 bits Sign TD TD TD TD TD TD TD TD TD TD TD 0 0 0 0
11 bits Sign TD TD TD TD TD TD TD TD TD TD 0 0 0 0 0
10 bits Sign TD TD TD TD TD TD TD TD TD 0 0 0 0 0 0
9 bits Sign TD TD TD TD TD TD TD TD 0 0 0 0 0 0 0