Low Cost Microprocessor Supervisory Circuits Data Sheet ADM705/ADM706/ADM707/ADM708 FEATURES FUNCTIONAL BLOCK DIAGRAMS Guaranteed RESET valid with V = 1 V CC WATCHDOG WATCHDOG WATCHDOG TRANSITION WATCHDOG 190 A quiescent current INPUT (WDI) TIMER DETECTOR OUTPUT (WDO) Precision supply voltage monitor V RESET AND 4.65 V (ADM705/ADM707) CC WATCHDOG TIMEBASE 4.40 V (ADM706/ADM708) 250A 200 ms reset pulse width MR RESET Debounced TTL/CMOS manual reset input (MR) RESET GENERATOR V CC Independent watchdog timer (ADM705/ADM706) 4.65V* 1.60 sec timeout (ADM705/ADM706) ADM705/ POWER-FAIL Active high reset output (ADM707/ADM708) ADM706 INPUT (PFI) POWER-FAIL OUTPUT (PFO) Voltage monitor for power fail or low battery warning 1.25V Superior upgrade for MAX705 to MAX708 * VOLTAGE REFERENCE = 4.65V (ADM705), 4.40V (ADM706) Figure 1. ADM705/ADM706 APPLICATIONS Microprocessor systems V CC Computers 250A RESET Controllers MR Intelligent instruments RESET RESET GENERATOR Critical microprocessor supply monitoring V CC 4.65V* ADM707/ ADM708 POWER-FAIL INPUT (PFI) POWER-FAIL 1.25V OUTPUT (PFO) * VOLTAGE REFERENCE = 4.65V (ADM707), 4.40V (ADM708) Figure 2. ADM707/ADM708 GENERAL DESCRIPTION The ADM705/ADM706/ADM707/ADM708 microprocessor The ADM705 and ADM706 are identical except for the reset supervisory circuits are suitable for monitoring 5 V power threshold monitor levels, which are 4.65 V and 4.40 V, respectively. supplies/batteries and microprocessor activity. The ADM707 and ADM708 provide a similar functionality to The ADM705/ADM706 provide power-supply monitoring the ADM705 and ADM706 and only differ in that a watchdog circuitry that generate a reset output during power-up, power- timer function is not available. Instead, an active high reset down, and brownout conditions. The reset output remains output (RESET) is available as well as the active low reset output operational with V as low as 1 V. Independent watchdog RESET CC ( ). The ADM707 and ADM708 are identical except for monitoring circuitry is also provided. This is activated if the the reset threshold monitor levels, which are 4.65 V and 4.40 V, watchdog input has not been toggled within 1.60 sec. respectively. In addition, there is a 1.25 V threshold detector to warn of All devices are available in narrow 8-lead PDIP and 8-lead SOIC power failures, to detect low battery conditions, or to monitor an packages. additional power supply. An active low, debounced manual reset MR input ( ) is also included. Rev. H 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 20022016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 00088-002 00088-001ADM705/ADM706/ADM707/ADM708 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Power Fail RESET Output ............................................................8 Applications ....................................................................................... 1 Manual Reset ..................................................................................8 Functional Block Diagrams ............................................................. 1 Watchdog Timer (ADM705/ADM706) .....................................8 General Description ......................................................................... 1 Power Fail Comparator .................................................................8 Revision History ............................................................................... 2 RESET Valid Below 1 V VCC ........................................................9 Specifications ..................................................................................... 3 Applications Information .............................................................. 10 Absolute Maximum Ratings ............................................................ 4 Monitoring Additional Supply Levels ...................................... 10 ESD Caution .................................................................................. 4 Microprocessor with Bidirectional RESET ............................. 10 Pin Configurations and Function Descriptions ........................... 5 Outline Dimensions ....................................................................... 11 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 12 Circuit Information .......................................................................... 8 REVISION HISTORY 1/16Rev. G to Rev. H 7/06Rev. D to Rev. E Changes to Table 3 ............................................................................ 5 Added RM-8 (MSOP) Package ......................................... Universal Changes to Power Fail Comparator Section and Figure 15 ........ 8 Changes to Table 2 ............................................................................. 4 Changes to Figure 16 ........................................................................ 9 Updated Outline Dimensions ....................................................... 12 Changes to Figure 18 and Figure 20 ............................................. 10 Changes to Ordering Guide .......................................................... 12 Updated Outline Dimensions ....................................................... 12 Changes to Ordering Guide .......................................................... 12 11/05Rev. C to Rev. D Updated Format .................................................................. Universal 3/08Rev. F to Rev. G Deleted Figure 2 ................................................................................. 4 Changes to Applications .................................................................. 1 Updated Outline Dimensions ....................................................... 11 Changes to Table 2 ............................................................................ 4 Changes to Ordering Guide .......................................................... 12 Changes to Figure 9 .......................................................................... 6 Changes to Figure 10, Figure 11, and Figure 12 ........................... 7 8/02Rev. B to Rev. C Changes to Figure 14 ........................................................................ 8 Removed RM-8 (SOIC) Package .................................... Universal Changes to Ordering Guide .......................................................... 12 Updated N-8 and R-8 Packages ....................................................... 8 2/07Rev. E to Rev. F Updated Format .................................................................. Universal Changes to Watchdog Timeout Period .......................................... 3 Replaced Pin Configurations and Function Descriptions Section .. 5 Rev. H Page 2 of 12