Microprocessor Supervisory Circuits ADM8690/ADM8691/ADM8692/ADM8693/ADM8695 FEATURES FUNCTIONAL BLOCK DIAGRAMS Upgrade for ADM690 to ADM695, MAX690 to MAX695 V BATT Specified over temperature V Low power consumption (0.7 mW) OUT Precision voltage monitor V CC Reset assertion down to 1 V V CC Low switch on resistance 0.7 normal, 7 in backup RESET 1 RESET 4.65V 2 GENERATOR High current drive (100 mA) Watchdog timer: 100 ms, 1.6 s, or adjustable WATCHDOG ADM8690/ WATCHDOG TRANSITION DETECTOR 400 nA standby current INPUT (WDI) (1.6s) ADM8692 Automatic battery backup power switching POWER FAIL Extremely fast gating of chip enable signals (3 ns) INPUT (PFI) POWER FAIL OUTPUT (PFO) 1.3V Voltage monitor for power fail Available in TSSOP package 1 VOLTAGE DETECTOR = 4.65V (ADM8690) 4.40V (ADM8692) APPLICATIONS 2 RESET PULSE WIDTH = 50ms (AD8690, ADM8692) Microprocessor systems Figure 1. ADM8690/ADM8692 Computers Controllers BATT ON Intelligent instruments ADM8691/ V Automotive systems BATT ADM8693/ ADM8695 V OUT PRODUCT HIGHLIGHTS V CC The ADM8690 and ADM8692 are available in 8-lead, PDIP CE IN CE packages and provide: OUT LOW LINE 1 1. Power-on reset output during power-up, power-down, and 4.65V RESET brownout conditions. The output remains RESET operational with V as low as 1 V. OSC IN RESET AND CC RESET WATCHDOG RESET GENERATOR 2. Battery backup switching for CMOS RAM, CMOS OSC SEL TIME BASE microprocessor, or other low power logic. 3. A reset pulse if the optional watchdog timer has not been WATCHDOG WATCHDOG WATCHDOG WATCHDOG INPUT (WDI) TRANSITION DETECTOR TIMER OUTPUT (WDO) toggled within a specified time. POWER FAIL 4. A 1.3 V threshold detector for power-fail warning, low battery POWER FAIL INPUT (PFI) OUTPUT (PFO) 1.3V detection, or to monitor a power supply other than 5 V. 1 VOLTAGE DETECTOR = 4.65V (ADM8691, ADM8695) The ADM8691, ADM8693, and ADM8695 are available in 16-lead 4.40V (ADM8693) PDIP and small outline packages (including TSSOP) and Figure 2. ADM8691/ADM8693/ADM8695 provide three additional functions: 1. Write protection of CMOS RAM or EEPROM. 2. Adjustable reset and watchdog timeout periods. 3. Separate watchdog timeout, backup battery switchover, and low V status outputs. CC Rev. B 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. 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All rights reserved. 00093-002 00093-001 ADM8690/ADM8691/ADM8692/ADM8693/ADM8695 TABLE OF CONTENTS Features .............................................................................................. 1 Power-Fail Warning Comparator ............................................. 13 Applications ....................................................................................... 1 Application Information ................................................................ 14 Product Highlights ........................................................................... 1 Increasing the Drive Current .................................................... 14 Functional Block Diagrams ............................................................. 1 Using a Rechargeable Battery for Backup ............................... 14 Revision History ............................................................................... 2 Adding Hysteresis to the Power-Fail Comparator ................. 14 General Description ......................................................................... 3 Monitoring the Status of the Battery ....................................... 14 Specifications ..................................................................................... 4 Alternate Watchdog Input Drive Circuits ............................... 15 Absolute Maximum Ratings ............................................................ 6 Typical Applications ....................................................................... 16 ESD Caution .................................................................................. 6 ADM8690 and ADM8692 ......................................................... 16 Pin Configurations and Function Descriptions ........................... 7 ADM8691, ADM8693, and ADM8695 ................................... 16 Typical Performance Characteristics ............................................. 8 RESET Output ............................................................................ 16 Circuit Information ........................................................................ 10 Power-Fail Detector ................................................................... 17 Battery Switchover Section ........................................................ 10 RAM Write Protection............................................................... 17 Power-Fail RESET Output ......................................................... 10 Watchdog Timer ......................................................................... 17 Outline Dimensions ....................................................................... 18 Watchdog Timer RESET ............................................................ 11 Ordering Guide .......................................................................... 19 Watchdog Output (WDO) ........................................................ 12 CE Gating and RAM Write Protection (ADM8691/ADM8693/ADM8695) ......................................... 12 REVISION HISTORY 6/11Rev. A to Rev. B Deleted ADM8694 ......................................................... Throughout Updated Figure 11, Figure 12, and Figure 13 ................................ 9 Updated Outline Dimensions ....................................................... 18 9/06Rev. 0 to Rev. A Updated Format .................................................................. Universal Changes to Absolute Maximum Ratings ....................................... 6 Updated Ordering Guide ............................................................... 20 2/97Revision 0: Initial Version Rev. B Page 2 of 20