3 V, Voltage Monitoring Microprocessor Supervisory Circuits Data Sheet ADM706P/ADM706R/ADM706S/ADM706T, ADM708R/ADM708S/ADM708T FEATURES FUNCTIONAL BLOCK DIAGRAMS Precision supply voltage monitor WATCHDOG WATCHDOG WATCHDOG 2.63 V (ADM706P, ADM706R, ADM708R) TRANSITION WATCHDOG INPUT (WDI) TIMER DETECTOR OUTPUT (WDO) 2.93 V (ADM706S, ADM708S) 3.08 V (ADM706T, ADM708T) V CC RESET AND WATCHDOG 100 A quiescent current TIMEBASE 70A 200 ms reset pulse width MR MR Debounced manual reset input ( ) RESET, RESET GENERATOR (P = RESET) Independent watchdog timer V CC 1.6 sec timeout (ADM706P, ADM706R, ADM706S, V * REF ADM706P/ADM706R/ ADM706T) POWER-FAIL ADM706S/ADM706T INPUT (PFI) POWER-FAIL Reset output OUTPUT (PFO) 1.25V Active high (ADM706P) * VOLTAGE REFERENCE = 2.63V (P/R), 2.93V (S), 3.08V (T) Active low (ADM706R, ADM706S, ADM706T) Figure 1. ADM706P/ADM706R/ADM706S/ADM706T Both active high and active low (ADM708R, ADM708S, ADM708T) V CC Voltage monitor for power fail or low battery warning 70A RESET RESET Guaranteed valid with VCC = 1 V MR RESET RESET Superior upgrade for MAX706P/R/S/T, MAX708R/S/T GENERATOR V CC APPLICATIONS V * REF ADM708R/ADM708S/ POWER-FAIL ADM708T Microprocessor systems INPUT (PFI) POWER-FAIL Computers 1.25V OUTPUT (PFO) Controllers * VOLTAGE REFERENCE = 2.63V (R), 2.93V (S), 3.08V (T) Intelligent instruments Figure 2. ADM708R/ADM708S/ADM708T Critical microprocessor monitoring Battery operated systems Portable instruments GENERAL DESCRIPTION The ADM706P/ADM706R/ADM706S/ADM706T and the The ADM706R, ADM706S, and ADM706T are identical except ADM708R/ADM708S/ADM708T microprocessor supervisory for the reset threshold monitor levels, which are 2.63 V, 2.93 V, and circuits are suitable for monitoring either 3 V or 3.3 V power 3.08 V, respectively. The ADM706P is identical to the ADM706R supplies. in that the reset threshold is 2.63 V. It differs only in that it has an active high reset output. The ADM706P/ADM706R/ADM706S/ADM706T provide power supply monitoring circuitry that generate a reset output The ADM708R/ADM708S/ADM708T provide similar functio- during power-up, power-down, and brownout conditions. The nality as the ADM706R/ADM706S/ADM706T and only differ reset output remains operational with VCC as low as 1 V. in that a watchdog timer function is not available. Instead, an Independent watchdog monitoring circuitry is also provided. This active high reset output (RESET) is provided in addition to the activates if the watchdog input does not toggle within 1.6 sec. RESET active low ( ) output. In addition, there is a 1.25 V threshold detector for a power fail All devices are available in narrow 8-lead PDIP and 8-lead warning, low battery detection, or to monitor an additional SOIC packages. power supply. An active low debounced MR input is also included. Rev. E Document Feedback 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20072016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 06435-002 06435-001ADM706P/ADM706R/ADM706S/ADM706T, ADM708R/ADM708S/ADM708T Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Manual Reset ............................................................................... 10 Applications ....................................................................................... 1 Watchdog Timer (ADM706P/ADM706R/ ADM706S/ADM706T) .............................................................. 10 Functional Block Diagrams ............................................................. 1 Power Fail Comparator .............................................................. 11 General Description ......................................................................... 1 Adding Hysteresis to the Power Fail Comparator ................. 11 Revision History ............................................................................... 2 RESET Valid Below 1 V VCC ..................................................... 11 Specif icat ions ..................................................................................... 3 Applications Information .............................................................. 12 Absolute Maximum Ratings ............................................................ 5 Monitoring Additional Supply Levels ...................................... 12 ESD Caution .................................................................................. 5 Microprocessors with Bidirectional RESET ........................... 12 Pin Configurations and Function Descriptions ........................... 6 Outline Dimensions ....................................................................... 13 Typical Performance Characteristics ............................................. 8 Ordering Guide .......................................................................... 14 Circuit Information ........................................................................ 10 Power Fail Reset .......................................................................... 10 REVISION HISTORY 1/16Rev. D to Rev. E 5/08Rev. B to Rev. C Changes to Table 3 ............................................................................ 6 Changes to Applications Section ..................................................... 1 Changes to Table 4 ............................................................................ 7 Changes to Table 2 ............................................................................. 5 Changes to Power Fail Comparator Section, Figure 17, Changes to Table 3 ............................................................................. 6 and Figure 18 ................................................................................... 10 Changes to Figure 8 ........................................................................... 7 Changes to Figure 20 and Figure 22 ............................................. 12 Changes to Figure 16 ......................................................................... 9 Changes to Ordering Guide .......................................................... 14 2/07Rev. A to Rev. B 10/14Rev. C to Rev. D Updated Format .................................................................. Universal Changes to Pin 4 Description Table 3 ........................................... 6 Changes to Table 1 ............................................................................. 3 Changes to Pin 4 Description Table 4 ........................................... 7 Updated Outline Dimensions ....................................................... 12 Changes to Ordering Guide .......................................................... 14 Changes to Ordering Guide .......................................................... 13 Rev. E Page 2 of 16