DS1813-10+T&R - Maxim Integrated

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GENERAL DESCRIPTION

The DS1813 EconoReset uses a precision

temperature reference and comparator circuit to

monitor the status of the power supply (VCC).

When an out-of-tolerance condition is detected,

an internal power-fail signal is generated which

forces reset to the active state. When VCC returns

to an in-tolerance condition, the reset signal is

kept in the active state for approximately 150ms

to allow the power supply and processor to

stabilize.

The DS1813 also monitors a pushbutton on the

reset output. If the reset line is pulled low, a reset

is generated upon release and will be held in reset

output low for typically 150ms.

FEATURES

 Automatically Restarts a Microprocessor

After Power Failure

 Monitors Pushbutton for External Override

 Maintains Reset for Typically 150ms After

VCC Returns to an In-Tolerance Condition

 Reduces Need for Discrete Components

 Precision Temperature-Compensated Voltage

Reference and Voltage Sensor

 Low-Cost TO-92 or Space-Saving Surface-

Mount SOT-23 Packages Available

 Efficient Open-Drain Output with Internal

5.5kΩ Pullup Resistor

 -40°C to +85°C Operating Temperature

PIN CONFIGURATIONS

PIN DESCRIPTION

TO-92 SOT-23

NAME FUNCTION

1 1

RST Active-Low

Reset Output

2 2 VCC Power Supply

3 3 GND Ground

DS1813

5V EconoReset with Pushbutton

www.maxim-ic.com

TOP VIEW

SOT-23 PACKAGE

See Mech.

Drawings Section

On Website

1 2 3

BOTTOM VIE

TO-92 PACKAGE

See Mech.

Drawings Section

On Website

DALLAS

DS1813

Econo

Reset

DS1813

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OPERATION—POWER MONITOR

The DS1813 provides the functions of detecting out-of-tolerance power-supply conditions and warning a

processor-based system of impending power failure. When VCC is detected as out-of-tolerance, the RST

signal is asserted. On power-up, RST is kept active for approximately 150ms after the power supply has

reached the selected tolerance. This allows the power supply and microprocessor to stabilize before RST

is released.

OPERATION—PUSHBUTTON RESET

The DS1813 provides for a pushbutton switch for manual reset control. When the DS1813 is not in a reset

cycle, a pushbutton reset can be generated by pulling the RST pin low for at least 1µs. When the

pushbutton is held low, the RST is forced active low and will remain active low for about 150ms after the

pushbutton is released. See Figure 2 for an application example and Figure 3 for the timing diagram.

Figure 1. Block Diagram (Open-Drain Output)

Figure 2. Application Example

DS1813

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Figure 3. Timing Diagram: Pushbutton Reset

Figure 4. Timing Diagram: Power-Up

Figure 5. Timing Diagram: Power-Down

DS1813

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ABSOLUTE MAXIMUM RATINGS

Voltage Range on VCC Pin Relative to Ground……………………………………………...-0.5V to +7.0V

Voltage Range on RST Relative to Ground………………………………….….……-0.5V to (VCC +0.5V)

Operating Temperature Range………………………………………………………………-40°C to +85°C

Storage Temperature Range……………………………………………………………….-55°C to +125°C

Soldering Temperature………………………………………….See IPC/JEDEC J-STD-020 Specification

This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation

sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect

reliability.

RECOMMENDED DC OPERATING CONDITIONS

(TA = -40°C to +85°C)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Supply Voltage VCC 0 5.5 V 1

DC ELECTRICAL CHARACTERISTICS

(VCC = 1.2V to 5.5V, TA = -40°C to +85°C.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Output Current at 0.4V IOL 10 mA 2, 3

Voltage Input Low VIL 0.4 V 1

Voltage Input High VIH 0.7 x

VCC V 1

Operating Current VCC < 5.5 ICC 30 40

µA 4

DS1813-5 4.50 4.62 4.75

DS1813-10 4.25 4.35 4.49

VCC Trip Point

DS1813-15

VCCTP

4.00 4.13 4.24

V 1

Internal Pullup Resistor RP 3.50 5.5 7.5

kΩ 6

Output Capacitance COUT 10 pF

AC ELECTRICAL CHARACTERISTICS

(VCC = 1.2V to 5.5V, TA = -40°C to +85°C.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Reset Active Time tRST 100 150 300 ms

VCC Detect to RST tRPD 2 5

µs

VCC Slew Rate

(VCCTP(MAX) - VCCTP(MIN)) tF 300 µs 7

VCC Slew Rate

(VCCTP(MIN) - VCCTP(MAX)) tR 0 ns

VCC Detect to RST t

RPU 100 150 300 ms 5

Pushbutton Detect to RST tPB 1

µs

Pushbutton Reset tPBRST 100 150 300 ms

DS1813

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Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor product.

No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

The Maxim logo is a registered trademark of Maxim Integrated Products, Inc. The Dallas logo is a registered trademark of Dallas Semiconductor Corporation.

NOTES:

1) All voltages are referenced to ground.

2) Measured with VCC ≥ 2.7V.

3) A 1kΩ external resistor may be required in some applications for proper operation of the

microprocessor reset control circuit.

4) Measured with RST output open.

5) tR = 5µs.

6) VOH and IOH are a function of the value of RP and the associated output load conditions.

7) This value is for reference in defining values for tRPD and should not be considered a requirement for

proper operation or use of the device.

PART MARKING CODES

“A,” “B,” and “C” represent the device type.

810 . . . . DS1810

811 . . . . DS1811

812 . . . . DS1812

813 . . . . DS1813

815 . . . . DS1815

816 . . . . DS1816

817 . . . . DS1817

818 . . . . DS1818

“D” represents the device tolerance.

A . . . . . . 5%

B . . . . . . 10%

C . . . . . . 15%

D . . . . . . 20%

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