Analog Devices ADM805, ADM802, ADM690A, ADM692A Datasheet

Microprocessor

a

ADM690A/ADM692A/ADM802L/M/ADM805L/M

FEATURES
Precision Supply Voltage Monitor

4.65 V ADM690A/ADM802L/ADM805L

4.40 V ADM692A/ADM802M/ADM805M
Reset Assertion Down to 1 V V
Reset Timeout—200 ms
Watchdog Timer—1.6 s
100 mA Quiescent Supply Current
Automatic Battery Backup Power Switching
Voltage Monitor for Power Fail
62% Power Fail Accuracy on ADM802L/M
Space-Saving MicroSOIC Package (ADM690A)

APPLICATIONS
Microprocessor Systems
Computers
Controllers
Intelligent Instruments

CC

V

BATT

V

WATCHDOG
INPUT (WDI)

POWER FAIL

INPUT (PFI)

Supervisory Circuits

FUNCTIONAL BLOCK DIAGRAM

BATTERY

SWITCHOVER

CC

4.65V*

WATCHDOG

TRANSITION DETECTOR

(1.6s)

1.25V

*4.4V FOR ADM692A/ADM802M/ADM805M

( ) = ADM805L/M ONLY

RESET

GENERATOR

ADM690A
ADM692A
ADM802L
ADM802M
ADM805L
ADM805M

V

OUT

RESET

(RESET)

POWER FAIL
OUTPUT (PFO)

GENERAL DESCRIPTION

The ADM690A/ADM692A/ADM802L/M/ADM805L/M
family of supervisory circuits offers complete single chip
solutions for power supply monitoring and battery control
functions in microprocessor systems. These functions include
µP reset, backup battery switchover, watchdog timer, and power
failure warning.

The ADM690A/ADM692A/ADM802L/M/ADM805L/M are
available in 8-pin packages and provide:

1. Power-on reset output during power-up, power-down and
brownout conditions. The

RESET output remains opera-

tional with VCC as low as 1 V.

2. Battery backup switching for CMOS RAM, CMOS
microprocessor or other low power devices.

3. A reset pulse if the optional watchdog timer has not been
toggled within 1.6 seconds.

4. A 1.25 V threshold detector for power fail warning, low battery
detection, or to monitor a power supply other than +5 V.

On the ADM690A/ADM802L/ADM805L the reset voltage
threshold is 4.65 V. On the ADM692A/ADM802M/
ADM805M, the reset voltage threshold is 4.40 V.

The ADM802L/ADM802M guarantee power fail accuracies to
±2%.

The ADM805L/M provides an active high reset output, RESET
instead of

RESET.

The family of products is fabricated using an advanced epitaxial
CMOS process combining low power consumption and high
reliability.

RESET assertion is guaranteed with VCC as low as 1 V.

They provide a pin-compatible upgrade for the MAX690A/
MAX692A/MAX802L/MAX802M/MAX805L

All parts are available in 8-pin DIP and SOIC packages. The
ADM690A is also available in a new space-saving microSOIC
package.

REV. 0

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 1996

ADM690A/ADM692A/ADM802L/M/ADM805L/M–SPECIFICATIONS

(VCC = 4.75 V to 5.5 V (ADM690A/ADM802L/ADM805L), VCC = 4.5 V to 5.5 V, (ADM692A/ADM802M/ADM805M), V
unless otherwise noted)

Parameter Min Typ Max Units Test Conditions/Comments

V

CC/VBATT

OPERATION

1

VCC Operating Voltage Range 1.0 5.5 V
Supply Current (Excludes I
Supply Current in Battery Backup Mode 0.05 1.0 µAV

) 70 100 µA

OUT

CC

Battery Standby Current 5.5 V > V

(+ = Discharge, – = Charge) –0.1 +0.02 µA
V

Output Voltage VCC – 0.02 VCC – 0.01 V I

OUT

V

in Battery Backup Mode V

OUT

V

– 0.5 VCC – 0.05 V I

CC

BATT

– 0.05 V

V

– 0.02 V I

CC

– 0.002 V I

BATT

OUT
OUT
OUT
OUT

Battery Switchover Threshold 20 mV Power Up

–20 mV Power Down

Battery Switchover Hysteresis 40 mV

RESET THRESHOLD

Reset Voltage Threshold

ADM690A, ADM802L, ADM805L 4.5 4.65 4.75 V
ADM692A, ADM802M, ADM805M 4.25 4.4 4.5 V
ADM802L 4.55 4.7 V T
ADM802M 4.30 4.45 V T

A
A

Reset Threshold Hysteresis 40 mV
Reset Timeout Delay 140 200 280 ms
RESET Output Voltage VCC – 1.5 V I

0.4 V I

0.3 V I

RESET Output Voltage 0.8 V I

V

– 1.5 V ADM805L/M, I

CC

SOURCE
SINK
SINK
SOURCE

0.4 V ADM805L/M, I

WATCHDOG TIMER

Watchdog Timeout Period 1.0 1.6 2.25 s
WDI Input Pulse Width 50 ns V

IL

WDI Input Threshold

Logic Low 0.8 V
Logic High 3.5 V

WDI Input Current 10 µA WDI = V

–10 µA WDI = 0 V

= +2.8 V, TA = T

BATT

= 0 V, V

CC

BATT

> V

= 2.8 V

+ 0.2 V

BATT

= 5 mA
= 50 mA
= 250 mA
= 250 µA, V

= 25°C, V
= 25°C, V

CC

Falling

CC

Falling

CC

< V

= 800 µA

= 3.2 mA
= 100 µA, V

= 4 µA, V

= 1 V

CC

= 1.1 V

CC

SOURCE

= 3.2 mA

SINK

= 800 µA

= 0.4, VIH = 0.8 (VCC)

CC

MIN

BATT

to T

– 0.2 V

MAX

POWER FAIL DETECTOR

PFI Input Threshold 1.20 1.25 1.30 V ADM690A, ADM692A, ADM805L/M

1.225 1.25 1.275 V ADM802L/M
PFI Input Current –25 0.01 +25 nA
PFO Output Voltage VCC – 1.5 V I

0.4 V I

NOTES

1

Either VCC or V

Specifications subject to change without notice.

can be 0 V if the other > +2.0 V.

BATT

SOURCE

= 3.2 mA

SINK

= 800 µA

–2–

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ADM690A/ADM692A/ADM802L/M/ADM805L/M

1
2
3
4

8
7
6
5

TOP VIEW

(Not to Scale)

ADM690A
ADM692A
ADM802L
ADM802M
ADM805L
ADM805M

PFO

WDI

RESET (RESET)

V

BATT

V

OUT

V

CC

GND

PFI

ABSOLUTE MAXIMUM RATINGS*

(TA = +25°C unless otherwise noted)

VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V

V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V

BATT

All Other Inputs . . . . . . . . . . . . . . . . . .–0.3 V to VCC + 0.3 V

Input Current

VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200 mA

V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 mA

BATT

GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA

Digital Output Current . . . . . . . . . . . . . . . . . . . . . . . . 20 mA

Power Dissipation, N-8 DIP . . . . . . . . . . . . . . . . . . . 400 mW

θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . 120°C/W

Power Dissipation, SO-8 SOIC . . . . . . . . . . . . . . . . . 500 mW

θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . 110°C/W

Operating Temperature Range

Industrial (A Version) . . . . . . . . . . . . . . . . –40°C to +85°C

Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . .+300°C

Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . .+215°C

Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . .+220°C

Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C

ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >4 kV

*Stresses above those listed under “Absolute Maximum Ratings” may cause

permanent damage to the device. This is a stress rating only and functional
operation of the device at these or any other conditions above those listed in the
operational sections of this specification is not implied. Exposure to absolute
maximum ratings for extended periods of time may affect device reliability.

ORDERING GUIDE

Temperature Package

Model Range Option

ADM690AAN –40°C to +85°C N-8
ADM690AARN –40°C to +85°C SO-8
ADM690AARM –40°C to +85°C RM-8

ADM692AAN –40°C to +85°C N-8
ADM692AARN –40°C to +85°C SO-8

ADM802LAN –40°C to +85°C N-8
ADM802LARN –40°C to +85°C SO-8

ADM802MAN –40°C to +85°C N-8
ADM802MARN –40°C to +85°C SO-8

ADM805LAN –40°C to +85°C N-8
ADM805LARN –40°C to +85°C SO-8

ADM805MAN –40°C to +85°C N-8
ADM805MARN –40°C to +85°C SO-8

PIN CONFIGURATIONS

PIN FUNCTION DESCRIPTION

Mnemonic Function

V
V

V

CC

BATT

OUT

Power Supply Input: +5 V Nominal.
Backup Battery Input. As VCC falls below the reset threshold and below V

to V
Output Voltage. When VCC is above the reset threshold, V

When V

. On power-up as VCC rises to 20 mV above V

OUT

is below the reset threshold, the higher of VCC or V

CC

BATT

, V

will be switched back to VCC.

OUT

is connected to VCC through an on chip switch.

OUT

BATT

BATT

is connected to V

by 20 mV, V

.

OUT

will be switched

BATT

GND 0 V. Ground reference for all signals.
PFI Power Fail Comparator Input. If PFI is less than 1.25 V, the power fail output

should be connected to V

or GND.

CC

PFO goes low. If unused, PFI

PFO Power Fail Comparator Output. If PFI is less than 1.25 V, the power fail output PFO goes low.
RESET Logic Output. RESET goes low if

1. V

falls below the Reset Threshold

CC

2. The watchdog timer is not serviced within its timeout period (1.6 seconds)
The reset threshold is typically 4.65 V for the ADM690A/ADM802L/ADM805L and 4.4 V for the ADM692A/

ADM802M/ADM805M.

RESET remains low for 200 ms after VCC returns above the threshold. RESET also

goes low for 200 ms if the watchdog timer is enabled but not serviced within its timeout period.

RESET Active high RESET output (ADM805L/M only). This is the inverse of

or V

whichever is higher.

BATT

RESET. The asserted (high) level is V

CC

WDI Watchdog Input. WDI is a three level input. If WDI remains either high or low for longer than 1.6 s, (RESET)

(RESET) is activated. The timer resets with each transition on the WDI line. The watchdog timer may be
disabled if WDI is left floating or is connected to a high impedance three stated logic output.

REV. 0

–3–