1. General description
The PCA9531 is an 8-bit I2C-bus and SMBus I/O expander optimized for dimming LEDs in
256 discrete steps for Red/Green/Blue (RGB) color mixing and back light applications.
The PCA9531 contains an internal oscillator with two user programmable blink rates and
duty cycles coupled to the output PWM. The LED brightness is controlled by setting the
blink rate high enough (> 100 Hz) that the blinking cannot be seen and then using the duty
cycle to vary the amount of time the LED is on and thus the average current through the
LED.
The initial setup sequence programs the two blink rates/duty cycles for each individual
PWM. From then on, only one command from the bus master is required to turn individual
LEDs ON, OFF, BLINK RATE 1 or BLINK RATE 2. Based on the programmed frequency
and duty cycle, BLINK RATE 1 and BLINK RATE 2 will cause the LEDs to appear at a
different brightness or blink at periods up to 1.69 second. The open-drain outputs directly
drive the LEDs with maximum output sink current of 25 mA per bit and 100 mA per
package.
To blink LEDs at periods greater than 1.69 second the bus master (MCU, MPU, DSP,
chip set, etc.) must send repeated commands to turn the LED on and off as is currently
done when using normal I/O expanders like the NXP Semiconductors PCF8574 or
PCA9554. Any bits not used for controlling the LEDs can be used for General Purpose
parallel Input/Output (GPIO) expansion, which provides a simple solution when additional
I/O is needed for ACPI power switches, sensors, push-buttons, alarm monitoring, fans,
etc.
The active LOW hardware reset pin (RESET) and Power-On Reset (POR) initializes the
registers to their default state causing the bits to be set HIGH (LED off).
Three hardware address pins on the PCA9531 allow eight devices to operate on the same
bus.
2. Features
nEight LED drivers (on, off, flashing at a programmable rate)
nTwo selectable, fully programmable blink rates (frequency and duty cycle) between
0.59 Hz and 152 Hz (1.69 second and 6.58 milliseconds)
n256 brightness steps
nInput/outputs not used as LED drivers can be used as regular GPIOs
nInternal oscillator requires no external components
nI2C-bus interface logic compatible with SMBus
nInternal power-on reset
PCA9531
8-bit I2C-bus LED dimmer
Rev. 06 — 19 February 2009 Product data sheet
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 2 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
nNoise filter on SCL/SDA inputs
nActive LOW reset input
nEight open-drain outputs directly drive LEDs to 25 mA
nEdge rate control on outputs
nNo glitch on power-up
nSupports hot insertion
nLow standby current
nOperating power supply voltage range of 2.3 V to 5.5 V
n0 Hz to 400 kHz clock frequency
nESD protection exceeds 2000 V HBM per JESD22-A114, 150 V MM per
JESD22-A115 and 1000 V CDM per JESD22-C101
nLatch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
nPackages offered: SO16, TSSOP16, HVQFN16
3. Ordering information
Table 1. Ordering information
T
amb
=
40
°
C to +85
°
C.
Type number Topside
mark Package
Name Description Version
PCA9531D PCA9531D SO16 plastic small outline package; 16 leads; body width 3.9 mm SOT109-1
PCA9531PW PCA9531 TSSOP16 plastic thin shrink small outline package; 16 leads;
body width 4.4 mm SOT403-1
PCA9531BS 9531 HVQFN16 plastic thermal enhanced very thin quad flat package; no leads;
16 terminals; body 4 ×4×0.85 mm SOT629-1
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 3 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
4. Block diagram
Only one I/O shown for clarity.
Fig 1. Block diagram of PCA9531
A0 A1 A2
002aac522
I2C-BUS
CONTROL
INPUT
FILTERS
PCA9531
POWER-ON
RESET
SCL
SDA
VDD
VSS
LEDn
RESET
OSCILLATOR PRESCALER 1
REGISTER
PRESCALER 0
REGISTER
PWM1
REGISTER
PWM0
REGISTER
INPUT
REGISTER
LED SELECT (LSn)
REGISTER
BLINK0
BLINK1
0
1
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Product data sheet Rev. 06 — 19 February 2009 4 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
5. Pinning information
5.1 Pinning
5.2 Pin description
Fig 2. Pin configuration for SO16 Fig 3. Pin configuration for TSSOP16
Fig 4. Pin configuration for HVQFN16
PCA9531D
A0 VDD
A1 SDA
A2 SCL
LED0 RESET
LED1 LED7
LED2 LED6
LED3 LED5
VSS LED4
002aac518
1
2
3
4
5
6
7
8
10
9
12
11
14
13
16
15
PCA9531PW
A0 VDD
A1 SDA
A2 SCL
LED0 RESET
LED1 LED7
LED2 LED6
LED3 LED5
VSS LED4
002aac519
1
2
3
4
5
6
7
8
10
9
12
11
14
13
16
15
002aac520
PCA9531BS
Transparent top view
LED2 LED6
LED1 LED7
LED0 RESET
A2 SCL
LED3
VSS
LED4
LED5
A1
A0
VDD
SDA
4 9
3 10
2 11
1 12
5
6
7
8
16
15
14
13
terminal 1
index area
Table 2. Pin description
Symbol Pin Description
SO16,
TSSOP16 HVQFN16
A0 1 15 address input 0
A1 2 16 address input 1
A2 3 1 address input 2
LED0 4 2 LED driver 0
LED1 5 3 LED driver 1
LED2 6 4 LED driver 2
LED3 7 5 LED driver 3
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 5 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
[1] HVQFN16 package die supply ground is connected to both VSS pin and exposed center pad. VSS pin must
be connected to supply ground for proper device operation. For enhanced thermal, electrical, and board
level performance, the exposed pad needs to be soldered to the board using a corresponding thermal pad
on the board and for proper heat conduction through the board, thermal vias need to be incorporated in the
PCB in the thermal pad region.
6. Functional description
Refer to Figure 1 “Block diagram of PCA9531”.
6.1 Device address
Following a START condition, the bus master must output the address of the slave it is
accessing. The address of the PCA9531 is shown in Figure 5. To conserve power, no
internal pull-up resistors are incorporated on the hardware selectable address pins and
they must be pulled HIGH or LOW.
The last bit of the address byte defines the operation to be performed. When set to logic 1
a read is selected, while a logic 0 selects a write operation.
VSS 86
[1] supply ground
LED4 9 7 LED driver 4
LED5 10 8 LED driver 5
LED6 11 9 LED driver 6
LED7 12 10 LED driver 7
RESET 13 11 reset input (active LOW)
SCL 14 12 serial clock line
SDA 15 13 serial data line
VDD 16 14 supply voltage
Table 2. Pin description
…continued
Symbol Pin Description
SO16,
TSSOP16 HVQFN16
Fig 5. PCA9531 slave address
002aac505
1 1 0 0 A2 A1 A0 R/W
fixed
slave address
hardware
selectable
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 6 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
6.2 Control register
Following the successful acknowledgement of the slave address, the bus master will send
a byte to the PCA9531, which will be stored in the Control register.
The lowest 3 bits are used as a pointer to determine which register will be accessed.
If the Auto-Increment flag is set, the three low order bits of the Control register are
automatically incremented after a read or write. This allows the user to program the
registers sequentially. The contents of these bits will rollover to ‘000’ after the last register
is accessed.
When Auto-Increment flag is set (AI = 1) and a read sequence is initiated, the sequence
must start by reading a register different from the Input register (B2 B1 B0 0 0 0).
Only the 3 least significant bits are affected by the AI flag. Unused bits must be
programmed with zeroes.
6.2.1 Control register definition
6.3 Register descriptions
6.3.1 INPUT - Input register
The INPUT register reflects the state of the device pins. Writes to this register will be
acknowledged but will have no effect.
Remark: The default value ‘X’ is determined by the externally applied logic level (normally
logic 1) when used for directly driving LED with pull-up to VDD.
Reset state: 00h
Fig 6. Control register
002aac506
0 0 0 AI 0 B2 B1 B0
register address
Auto-Increment flag
Table 3. Register summary
B2 B1 B0 Symbol Access Description
0 0 0 INPUT read only input register
0 0 1 PSC0 read/write frequency prescaler 0
0 1 0 PWM0 read/write PWM register 0
0 1 1 PSC1 read/write frequency prescaler 1
1 0 0 PWM1 read/write PWM register 1
1 0 1 LS0 read/write LED0 to LED3 selector
1 1 0 LS1 read/write LED4 to LED7 selector
Table 4. INPUT - Input register description
Bit 76543210
Symbol LED7 LED6 LED5 LED4 LED3 LED2 LED1 LED0
Default XXXXXXXX
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 7 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
6.3.2 PCS0 - Frequency Prescaler 0
PSC0 is used to program the period of the PWM output.
The period of BLINK0 = (PSC0 + 1) / 152.
6.3.3 PWM0 - Pulse Width Modulation 0
The PWM0 register determines the duty cycle of BLINK0. The outputs are LOW (LED on)
when the count is less than the value in PWM0 and HIGH (LED off) when it is greater. If
PWM0 is programmed with 00h, then the PWM0 output is always HIGH (LED off).
The duty cycle of BLINK0 = PWM0 / 256.
6.3.4 PCS1 - Frequency Prescaler 1
PSC1 is used to program the period of the PWM output.
The period of BLINK1 = (PSC1 + 1) / 152.
6.3.5 PWM1 - Pulse Width Modulation 1
The PWM1 register determines the duty cycle of BLINK1. The outputs are LOW (LED on)
when the count is less than the value in PWM1 and HIGH (LED off) when it is greater. If
PWM1 is programmed with 00h, then the PWM1 output is always HIGH (LED off).
The duty cycle of BLINK1 = PWM1 / 256.
Table 5. PSC0 - Frequency Prescaler 0 register description
Bit 76543210
Symbol PSC0[7] PSC0[6] PSC0[5] PSC0[4] PSC0[3] PSC0[2] PSC0[1] PSC0[0]
Default 11111111
Table 6. PWM0 - Pulse Width Modulation 0 register description
Bit 76543210
Symbol PWM0
[7] PWM0
[6] PWM0
[5] PWM0
[4] PWM0
[3] PWM0
[2] PWM0
[1] PWM0
[0]
Default 10000000
Table 7. PSC1 - Frequency Prescaler 1 register description
Bit 76543210
Symbol PSC1[7] PSC1[6] PSC1[5] PSC1[4] PSC1[3] PSC1[2] PSC1[1] PSC1[0]
Default 00000000
Table 8. PWM1 - Pulse Width Modulation 1 register description
Bit 76543210
Symbol PWM1
[7] PWM1
[6] PWM1
[5] PWM1
[4] PWM1
[3] PWM1
[2] PWM1
[1] PWM1
[0]
Default 10000000
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Product data sheet Rev. 06 — 19 February 2009 8 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
6.3.6 LS0 to LS1 - LED selector registers
The LSn LED select registers determine the source of the LED data.
00 = output is set high-impedance (LED off; default)
01 = output is set LOW (LED on)
10 = output blinks at PWM0 rate
11 = output blinks at PWM1 rate
6.4 Pins used as GPIOs
LED pins not used to control LEDs can be used as General Purpose I/Os (GPIOs).
For use as input, set LEDn to high-impedance (00) and then read the pin state via the
Input register.
For use as output, connect external pull-up resistor to the pin and size it according to the
DC recommended operating characteristics. LEDn output pin is HIGH when the output is
programmed as high-impedance, and LOW when the output is programmed LOW through
the ‘LED selector’ register. The output can be pulse-width controlled when PWM0 or
PWM1 are used.
6.5 Power-on reset
When power is applied to VDD, an internal Power-On Reset (POR) holds the PCA9531 in
a reset condition until VDD has reached VPOR. At that point, the reset condition is released
and the PCA9531 registers are initialized to their default states, all the outputs in the
OFF state. Thereafter, VDD must be lowered below 0.2 V to reset the device.
6.6 External RESET
A reset can be accomplished by holding the RESET pin LOW for a minimum of tw(rst). The
PCA9531 registers and I2C-bus state machine will be held in their default states until the
RESET input is once again HIGH.
This input requires a pull-up resistor to VDD if no active connection is used.
Table 9. LS0 to LS1 - LED selector registers bit description
Legend: * default value.
Register Bit Value Description
LS0 - LED0 to LED3 selector
LS0 7:6 00* LED3 selected
5:4 00* LED2 selected
3:2 00* LED1 selected
1:0 00* LED0 selected
LS1 - LED4 to LED7 selector
LS1 7:6 00* LED7 selected
5:4 00* LED6 selected
3:2 00* LED5 selected
1:0 00* LED4 selected
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 9 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
7. Characteristics of the I2C-bus
The I2C-bus is for 2-way, 2-line communication between different ICs or modules. The two
lines are a serial data line (SDA) and a serial clock line (SCL). Both lines must be
connected to a positive supply via a pull-up resistor when connected to the output stages
of a device. Data transfer may be initiated only when the bus is not busy.
7.1 Bit transfer
One data bit is transferred during each clock pulse. The data on the SDA line must remain
stable during the HIGH period of the clock pulse as changes in the data line at this time
will be interpreted as control signals (see Figure 7).
7.1.1 START and STOP conditions
Both data and clock lines remain HIGH when the bus is not busy. A HIGH-to-LOW
transition of the data line while the clock is HIGH is defined as the START condition (S). A
LOW-to-HIGH transition of the data line while the clock is HIGH is defined as the STOP
condition (P) (see Figure 8).
7.2 System configuration
A device generating a message is a ‘transmitter’; a device receiving is the ‘receiver’. The
device that controls the message is the ‘master’ and the devices which are controlled by
the master are the ‘slaves’ (see Figure 9).
Fig 7. Bit transfer
mba607
data line
stable;
data valid
change
of data
allowed
SDA
SCL
Fig 8. Definition of START and STOP conditions
mba608
SDA
SCL P
STOP condition
S
START condition
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 10 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
7.3 Acknowledge
The number of data bytes transferred between the START and the STOP conditions from
transmitter to receiver is not limited. Each byte of eight bits is followed by one
acknowledge bit. The acknowledge bit is a HIGH level put on the bus by the transmitter,
whereas the master generates an extra acknowledge related clock pulse.
A slave receiver which is addressed must generate an acknowledge after the reception of
each byte. Also a master must generate an acknowledge after the reception of each byte
that has been clocked out of the slave transmitter. The device that acknowledges has to
pull down the SDA line during the acknowledge clock pulse, so that the SDA line is stable
LOW during the HIGH period of the acknowledge related clock pulse; set-up and hold
times must be taken into account.
A master receiver must signal an end of data to the transmitter by not generating an
acknowledge on the last byte that has been clocked out of the slave. In this event, the
transmitter must leave the data line HIGH to enable the master to generate a STOP
condition.
Fig 9. System configuration
002aaa966
MASTER
TRANSMITTER/
RECEIVER
SLAVE
RECEIVER SLAVE
TRANSMITTER/
RECEIVER
MASTER
TRANSMITTER MASTER
TRANSMITTER/
RECEIVER
SDA
SCL
I2C-BUS
MULTIPLEXER
SLAVE
Fig 10. Acknowledgement on the I2C-bus
002aaa987
S
START
condition
9821
clock pulse for
acknowledgement
not acknowledge
acknowledge
data output
by transmitter
data output
by receiver
SCL from master
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 11 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
7.4 Bus transactions
Fig 11. Write to register
0 AS
slave address
START condition R/W acknowledge
from slave
002aac507
0 0 AI 0 B2B1B00
command byte
A
acknowledge
from slave
12345678SCL 9
SDA DATA 1 A
write to register
data out from port
tv(Q)
acknowledge
from slave
DATA 1 VALID
data to register
1 0 0 A2 A1 A01
Fig 12. Read from register
1 0 0 A2 A1 A0 0 AS1
START condition R/W
acknowledge
from slave
002aac508
A
acknowledge
from slave
SDA
A P
acknowledge
from master
data from register
DATA (first byte)
slave address
STOP
condition
S
(repeated)
START condition
(cont.)
(cont.) 1 A
R/W
acknowledge
from slave
slave address
at this moment master-transmitter becomes master-receiver
and slave-receiver becomes slave-transmitter
NA
no acknowledge
from master
data from register
DATA (last byte)
command byte
0 0 AI 0 B2 B10B0
Auto-Increment
register address
if AI = 1
1 0 0 A2 A1 A01
Remark: This figure assumes the command byte has previously been programmed with 00h.
Fig 13. Read Input port register
1 0 0 A2 A1 A0 1 AS1
START condition R/W acknowledge
from slave
002aac509
A
acknowledge
from master
SDA NA
read from
port
data into
port
P
th(D)
data from port
no acknowledge
from master
data from port
DATA 4
slave address
DATA 1
STOP
condition
DATA 2 DATA 3 DATA 4
tsu(D)
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 12 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
8. Application design-in information
8.1 Minimizing IDD when the I/Os are used to control LEDs
When the I/Os are used to control LEDs, they are normally connected to VDD through a
resistor as shown in Figure 14. Since the LED acts as a diode, when the LED is off the
I/O VI is about 1.2 V less than VDD. The supply current, IDD, increases as VI becomes
lower than VDD and is specified as IDD in Table 12 “Static characteristics”.
Designs needing to minimize current consumption, such as battery power applications,
should consider maintaining the I/O pins greater than or equal to VDD when the LED is off.
Figure 15 shows a high value resistor in parallel with the LED. Figure 16 shows VDD less
than the LED supply voltage by at least 1.2 V. Both of these methods maintain the I/O VI
at or above VDD and prevents additional supply current consumption when the LED is off.
LED0 to LED5 are used as LED drivers.
LED6 and LED7 are used as regular GPIOs.
Fig 14. Typical application
PCA9531
LED0
LED1
SDA
SCL
RESET
3.3 V
I2C-BUS/SMBus
MASTER
002aac523
SDA
SCL
VDD
A2
A1
A0
VSS
5 V
10 k
LED2
LED3
LED4
LED5
LED6
LED7 GPIOs
10 k10 k
Fig 15. High value resistor in parallel with
the LED Fig 16. Device supplied by a lower voltage
002aac189
LED
VDD
LEDn
100 k
VDD
002aac190
LED
VDD
LEDn
3.3 V 5 V
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 13 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
8.2 Programming example
The following example will show how to set LED0 to LED3 on. It will then set LED4 and
LED5 to blink at 1 Hz at a 50 % duty cycle. LED6 and LED7 will be set to be dimmed at
25 % of their maximum brightness (duty cycle = 25 %).
9. Limiting values
Table 10. Programming PCA9531
Program sequence I2C-bus
START S
PCA9531 address with A0 to A2 = LOW C0h
PSC0 subaddress + Auto-Increment 11h
Set prescaler PSC0 to achieve a period of 1 second:
PSC0 = 151
97h
Set PWM0 duty cycle to 50 %:
PWM0 = 128
80h
Set prescaler PCS1 to dim at maximum frequency:
PSC1 = 0
00h
Set PWM1 output duty cycle to 25 %:
PWM1 = 64
40h
Set LED0 to LED3 on 55h
Set LED4 and LED5 to PWM0, and LED6 or LED7 to PWM1 FAh
STOP P
Blink period 1 PSC0 1+
152
------------------------
==
PWM0
256
----------------- 0.5=
Blink period max=
PWM1
256
----------------- 0.25=
Table 11. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter Conditions Min Max Unit
VDD supply voltage 0.5 +6.0 V
VI/O voltage on an input/output pin VSS 0.5 5.5 V
IO(LEDn) output current on pin LEDn - ±25 mA
ISS ground supply current - 200 mA
Ptot total power dissipation - 400 mW
Tstg storage temperature 65 +150 °C
Tamb ambient temperature operating 40 +85 °C
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 14 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
10. Static characteristics
[1] Typical limits at VDD = 3.3 V, Tamb =25°C.
[2] Additional current for one LED I/O at a time where VI= 4.3 V.
[3] VDD must be lowered to 0.2 V in order to reset part.
[4] Each I/O must be externally limited to a maximum of 25 mA and the device must be limited to a maximum current of 100 mA.
Table 12. Static characteristics
V
DD
= 2.3 V to 5.5 V; V
SS
=0V; T
amb
=
40
°
C to +85
°
C; unless otherwise specified.
Symbol Parameter Conditions Min Typ[1] Max Unit
Supplies
VDD supply voltage 2.3 - 5.5 V
IDD supply current operating mode; VDD = 5.5 V;
VI=V
DD or VSS; fSCL = 100 kHz - 350 500 µA
Istb standby current Standby mode; VDD = 5.5 V;
VI=V
DD or VSS; fSCL = 0 kHz - 1.9 5.0 µA
IDD additional quiescent supply
current Standby mode; VDD = 5.5 V;
LED I/O at VI= 4.3 V; fSCL = 0 kHz [2] - - 200 µA
VPOR power-on reset voltage no load; VI=V
DD or VSS [3] - 1.7 2.2 V
Input SCL; input/output SDA
VIL LOW-level input voltage 0.5 - +0.3VDD V
VIH HIGH-level input voltage 0.7VDD - 5.5 V
IOL LOW-level output current VOL = 0.4 V 3 6.5 - mA
ILleakage current VI=V
DD =V
SS 1- +1 µA
Ciinput capacitance VI=V
SS - 3.7 5 pF
I/Os
VIL LOW-level input voltage 0.5 - +0.8 V
VIH HIGH-level input voltage 2.0 - 5.5 V
IOL LOW-level output current VOL = 0.4 V
VDD = 2.3 V [4] 9-- mA
VDD = 3.0 V [4] 12 - - mA
VDD = 5.0 V [4] 15 - - mA
VOL = 0.7 V
VDD = 2.3 V [4] 15 - - mA
VDD = 3.0 V [4] 20 - - mA
VDD = 5.0 V [4] 25 - - mA
ILI input leakage current VDD = 3.6 V; VI= 0 V or VDD 1- +1 µA
Cio input/output capacitance - 2.5 5 pF
Select inputs A0, A1, A2; RESET
VIL LOW-level input voltage 0.5 - +0.8 V
VIH HIGH-level input voltage A0; RESET 2.0 - 5.5 V
A1; A2 2.0 - VDD + 0.5 V
ILI input leakage current 1- +1 µA
Ciinput capacitance VI=V
SS - 2.3 5 pF
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 15 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
(1) maximum
(2) average
(3) minimum
(1) maximum
(2) average
(3) minimum
Fig 17. Typical frequency variation over process at
VDD = 2.3 V to 3.0 V Fig 18. Typical frequency variation over process at
VDD = 3.0 V to 5.5 V
20 %
0 %
20 %
percent
variation
40 %
Tamb (°C)
40 10020
002aac524
0 20406080
(2)
(1)
(3) 20 %
0 %
20 %
percent
variation
40 %
Tamb (°C)
40 10020
002aac525
0 20406080
(1)
(2)
(3)
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 16 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
11. Dynamic characteristics
[1] tVD;ACK = time for Acknowledgement signal from SCL LOW to SDA (out) LOW.
[2] tVD;DAT = minimum time for SDA data output to be valid following SCL LOW.
[3] Cb= total capacitance of one bus line in pF.
[4] Resetting the device while actively communicating on the bus may cause glitches or errant STOP conditions.
[5] Upon reset, the full delay will be the sum of trst and the RC time constant of the SDA bus.
Table 13. Dynamic characteristics
Symbol Parameter Conditions Standard-mode
I2C-bus Fast-mode I2C-bus Unit
Min Max Min Max
fSCL SCL clock frequency 0 100 0 400 kHz
tBUF bus free time between a STOP and
START condition 4.7 - 1.3 - µs
tHD;STA hold time (repeated) START condition 4.0 - 0.6 - µs
tSU;STA set-up time for a repeated START
condition 4.7 - 0.6 - µs
tSU;STO set-up time for STOP condition 4.0 - 0.6 - µs
tHD;DAT data hold time 0 - 0 - ns
tVD;ACK data valid acknowledge time [1] - 600 - 600 ns
tVD;DAT data valid time LOW-level [2] - 600 - 600 ns
HIGH-level [2] - 1500 - 600 ns
tSU;DAT data set-up time 250 - 100 - ns
tLOW LOW period of the SCL clock 4.7 - 1.3 - µs
tHIGH HIGH period of the SCL clock 4.0 - 0.6 - µs
trrise time of both SDA and SCL signals - 1000 20 + 0.1Cb[3] 300 ns
tffall time of both SDA and SCL signals - 300 20 + 0.1Cb[3] 300 ns
tSP pulse width of spikes that must be
suppressed by the input filter - 50 - 50 ns
Port timing
tv(Q) data output valid time - 200 - 200 ns
tsu(D) data input set-up time 100 - 100 - ns
th(D) data input hold time 1 - 1 - µs
Reset
tw(rst) reset pulse width 6 - 6 - ns
trec(rst) reset recovery time 0 - 0 - ns
trst reset time [4][5] 400 - 400 - ns
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 17 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
Fig 19. Definition of RESET timing
SDA
SCL
002aac193
trst
50 %
30 %
50 % 50 %
50 %
trec(rst) tw(rst)
RESET
LEDn LED off
START
trst
ACK or read cycle
Fig 20. Definition of timing
tSP
tBUF
tHD;STA PP S
tLOW
tr
tHD;DAT
tf
tHIGH tSU;DAT tSU;STA
Sr
tHD;STA
tSU;STO
SDA
SCL
002aaa986
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 18 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
12. Test information
Rise and fall times refer to VIL and VIH.
Fig 21. I2C-bus timing diagram
SCL
SDA
tHD;STA tSU;DAT tHD;DAT
tf
tBUF
tSU;STA tLOW tHIGH
tVD;ACK
002aab175
tSU;STO
protocol START
condition
(S)
bit 7
MSB
(A7)
bit 6
(A6) bit 0
(R/W) acknowledge
(A)
STOP
condition
(P)
1/fSCL
tr
tVD;DAT
RL = load resistor for LEDn. RL for SDA and SCL > 1 k (3 mA or less current).
CL = load capacitance includes jig and probe capacitance.
RT = termination resistance should be equal to the output impedance Zo of the pulse generators.
Fig 22. Test circuitry for switching times
PULSE
GENERATOR
VO
CL
50 pF
RL
500
002aab880
RT
VI
VDD
DUT
VDD
open
VSS
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 19 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
13. Package outline
Fig 23. Package outline SOT109-1 (SO16)
X
wM
θ
A
A1
A2
bp
D
HE
Lp
Q
detail X
E
Z
e
c
L
vMA
(A )
3
A
8
9
1
16
y
pin 1 index
UNIT A
max. A1A2A3bpcD
(1) E(1) (1)
eH
ELL
pQZywv θ
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm
inches
1.75 0.25
0.10 1.45
1.25 0.25 0.49
0.36 0.25
0.19 10.0
9.8 4.0
3.8 1.27 6.2
5.8 0.7
0.6 0.7
0.3 8
0
o
o
0.25 0.1
DIMENSIONS (inch dimensions are derived from the original mm dimensions)
Note
1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included.
1.0
0.4
SOT109-1 99-12-27
03-02-19
076E07 MS-012
0.069 0.010
0.004 0.057
0.049 0.01 0.019
0.014 0.0100
0.0075 0.39
0.38 0.16
0.15 0.05
1.05
0.041
0.244
0.228 0.028
0.020 0.028
0.012
0.01
0.25
0.01 0.004
0.039
0.016
0 2.5 5 mm
scale
SO16: plastic small outline package; 16 leads; body width 3.9 mm SOT109-1
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 20 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
Fig 24. Package outline SOT403-1 (TSSOP16)
UNIT A1A2A3bpcD
(1) E(2) (1)
eH
ELL
pQZywv θ
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm 0.15
0.05 0.95
0.80 0.30
0.19 0.2
0.1 5.1
4.9 4.5
4.3 0.65 6.6
6.2 0.4
0.3 0.40
0.06 8
0
o
o
0.13 0.10.21
DIMENSIONS (mm are the original dimensions)
Notes
1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.
2. Plastic interlead protrusions of 0.25 mm maximum per side are not included.
0.75
0.50
SOT403-1 MO-153 99-12-27
03-02-18
wM
bp
D
Z
e
0.25
18
16 9
θ
A
A1
A2
Lp
Q
detail X
L
(A )
3
HE
E
c
vMA
X
A
y
0 2.5 5 mm
scale
TSSOP16: plastic thin shrink small outline package; 16 leads; body width 4.4 mm SOT403-1
A
max.
1.1
pin 1 index
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 21 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
Fig 25. Package outline SOT629-1 (HVQFN16)
terminal 1
index area
0.651
A1Eh
b
UNIT ye
0.2
c
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm 4.1
3.9
Dh
2.25
1.95
y1
4.1
3.9 2.25
1.95
e1
1.95
e2
1.95
0.38
0.23
0.05
0.00 0.05 0.1
DIMENSIONS (mm are the original dimensions)
SOT629-1 MO-220 - - -- - -
0.75
0.50
L
0.1
v
0.05
w
0 2.5 5 mm
scale
SOT629-1
HVQFN16: plastic thermal enhanced very thin quad flat package; no leads;
16 terminals; body 4 x 4 x 0.85 mm
A(1)
max.
AA1c
detail X
y
y1C
e
L
Eh
Dh
e
e1
b
58
16 13
12
9
4
1
X
D
E
C
BA
e2
01-08-08
02-10-22
terminal 1
index area
1/2 e
1/2 e
AC
CB
vM
wM
E(1)
Note
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.
D(1)
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 22 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
14. Handling information
All input and output pins are protected against ElectroStatic Discharge (ESD) under
normal handling. When handling ensure that the appropriate precautions are taken as
described in
JESD625-A
or equivalent standards.
15. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note
AN10365 “Surface mount reflow
soldering description”
.
15.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
15.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
Through-hole components
Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
15.3 Wave soldering
Key characteristics in wave soldering are:
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 23 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
Solder bath specifications, including temperature and impurities
15.4 Reflow soldering
Key characteristics in reflow soldering are:
Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 26) than a SnPb process, thus
reducing the process window
Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 14 and 15
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 26.
Table 14. SnPb eutectic process (from J-STD-020C)
Package thickness (mm) Package reflow temperature (°C)
Volume (mm3)
< 350 350
< 2.5 235 220
2.5 220 220
Table 15. Lead-free process (from J-STD-020C)
Package thickness (mm) Package reflow temperature (°C)
Volume (mm3)
< 350 350 to 2000 > 2000
< 1.6 260 260 260
1.6 to 2.5 260 250 245
> 2.5 250 245 245
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 24 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
For further information on temperature profiles, refer to Application Note
AN10365
“Surface mount reflow soldering description”
.
16. Abbreviations
MSL: Moisture Sensitivity Level
Fig 26. Temperature profiles for large and small components
001aac844
temperature
time
minimum peak temperature
= minimum soldering temperature
maximum peak temperature
= MSL limit, damage level
peak
temperature
Table 16. Abbreviations
Acronym Description
CDM Charged Device Model
DSP Digital Signal Processor
DUT Device Under Test
ESD ElectroStatic Discharge
GPIO General Purpose Input/Output
HBM Human Body Model
I2C-bus Inter-Integrated Circuit bus
LED Light Emitting Diode
MCU Microcontroller
MM Machine Model
MPU Microprocessor
POR Power-On Reset
RC Resistor-Capacitor network
SMBus System Management Bus
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 25 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
17. Revision history
Table 17. Revision history
Document ID Release date Data sheet status Change notice Supersedes
PCA9531_6 20090219 Product data sheet - PCA9531_5
Modifications: Type number PCA9531BS3 is withdrawn, and is deleted from this data sheet
Section 2 “Features”, last bullet item: deleted “(SOT629-1 and SOT758-1 versions)”
Section 3 “Ordering information”: type number PCA9531BS3 removed from table
Section 5.1 “Pinning”: deleted HVQFN16 (SOT758-1) pin configuration
Section 13 “Package outline”: deleted package outline SOT758-1
Table 12 “Static characteristics”:
Max value for Istb changed from “3.0 µA” to “5.0 µA”
Max value for IDD changed from “800 µA” to “200 µA”
Added (new) Table note [2] and its reference at IDD
Conditions for IDD changed from “every LED I/O at VI= 4.3 V” to “LED I/O at VI= 4.3 V”
under sub-section “I/Os”, changed symbol from “IL” (input leakage current) to “ILI
Updated soldering information
PCA9531_5 20070912 Product data sheet - PCA9531_4
PCA9531_4 20070226 Product data sheet - PCA9531_3
PCA9531_3 20061102 Product data sheet - PCA9531_2
PCA9531_2
(9397 750 13689) 20041001 Product data sheet - PCA9531_1
PCA9531_1
(9397 750 12292) 20031110 Product data 853-2407 30411
(20030906) -
PCA9531_6 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 06 — 19 February 2009 26 of 27
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
18. Legal information
18.1 Data sheet status
[1] Please consult the most recently issued document before initiating or completing a design.
[2] The term ‘short data sheet’ is explained in section “Definitions”.
[3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
18.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
18.3 Disclaimers
General — Information in this document is believed to be accurate and
reliable. However, NXP Semiconductors does not give any representations or
warranties, expressed or implied, as to the accuracy or completeness of such
information and shall have no liability for the consequences of use of such
information.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in medical, military, aircraft,
space or life support equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) may cause permanent
damage to the device. Limiting values are stress ratings only and operation of
the device at these or any other conditions above those given in the
Characteristics sections of this document is not implied. Exposure to limiting
values for extended periods may affect device reliability.
Terms and conditions of sale — NXP Semiconductors products are sold
subject to the general terms and conditions of commercial sale, as published
at http://www.nxp.com/profile/terms, including those pertaining to warranty,
intellectual property rights infringement and limitation of liability, unless
explicitly otherwise agreed to in writing by NXP Semiconductors. In case of
any inconsistency or conflict between information in this document and such
terms and conditions, the latter will prevail.
No offer to sell or license — Nothing in this document may be interpreted
or construed as an offer to sell products that is open for acceptance or the
grant, conveyance or implication of any license under any copyrights, patents
or other industrial or intellectual property rights.
18.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
I2C-bus — logo is a trademark of NXP B.V.
19. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Document status[1][2] Product status[3] Definition
Objective [short] data sheet Development This document contains data from the objective specification for product development.
Preliminary [short] data sheet Qualification This document contains data from the preliminary specification.
Product [short] data sheet Production This document contains the product specification.
NXP Semiconductors PCA9531
8-bit I2C-bus LED dimmer
© NXP B.V. 2009. All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 19 February 2009
Document identifier: PCA9531_6
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
20. Contents
1 General description. . . . . . . . . . . . . . . . . . . . . . 1
2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3 Ordering information. . . . . . . . . . . . . . . . . . . . . 2
4 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5 Pinning information. . . . . . . . . . . . . . . . . . . . . . 4
5.1 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4
6 Functional description . . . . . . . . . . . . . . . . . . . 5
6.1 Device address. . . . . . . . . . . . . . . . . . . . . . . . . 5
6.2 Control register. . . . . . . . . . . . . . . . . . . . . . . . . 6
6.2.1 Control register definition . . . . . . . . . . . . . . . . . 6
6.3 Register descriptions . . . . . . . . . . . . . . . . . . . . 6
6.3.1 INPUT - Input register. . . . . . . . . . . . . . . . . . . . 6
6.3.2 PCS0 - Frequency Prescaler 0. . . . . . . . . . . . . 7
6.3.3 PWM0 - Pulse Width Modulation 0. . . . . . . . . . 7
6.3.4 PCS1 - Frequency Prescaler 1. . . . . . . . . . . . . 7
6.3.5 PWM1 - Pulse Width Modulation 1. . . . . . . . . . 7
6.3.6 LS0 to LS1 - LED selector registers . . . . . . . . . 8
6.4 Pins used as GPIOs . . . . . . . . . . . . . . . . . . . . . 8
6.5 Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.6 External RESET . . . . . . . . . . . . . . . . . . . . . . . . 8
7 Characteristics of the I2C-bus. . . . . . . . . . . . . . 9
7.1 Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7.1.1 START and STOP conditions . . . . . . . . . . . . . . 9
7.2 System configuration . . . . . . . . . . . . . . . . . . . . 9
7.3 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.4 Bus transactions. . . . . . . . . . . . . . . . . . . . . . . 11
8 Application design-in information . . . . . . . . . 12
8.1 Minimizing IDD when the I/Os are used to
control LEDs. . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.2 Programming example . . . . . . . . . . . . . . . . . . 13
9 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 13
10 Static characteristics. . . . . . . . . . . . . . . . . . . . 14
11 Dynamic characteristics . . . . . . . . . . . . . . . . . 16
12 Test information. . . . . . . . . . . . . . . . . . . . . . . . 18
13 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 19
14 Handling information. . . . . . . . . . . . . . . . . . . . 22
15 Soldering of SMD packages . . . . . . . . . . . . . . 22
15.1 Introduction to soldering . . . . . . . . . . . . . . . . . 22
15.2 Wave and reflow soldering . . . . . . . . . . . . . . . 22
15.3 Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 22
15.4 Reflow soldering. . . . . . . . . . . . . . . . . . . . . . . 23
16 Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . 24
17 Revision history. . . . . . . . . . . . . . . . . . . . . . . . 25
18 Legal information . . . . . . . . . . . . . . . . . . . . . . 26
18.1 Data sheet status. . . . . . . . . . . . . . . . . . . . . . 26
18.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
18.3 Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 26
18.4 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 26
19 Contact information . . . . . . . . . . . . . . . . . . . . 26
20 Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27