Microprocessor Supervisory Circuits Data Sheet ADM8690/ADM8691/ADM8695 FEATURES FUNCTIONAL BLOCK DIAGRAMS Upgrade for the ADM690, ADM691, ADM695 and V BATT for the MAX690, MAX691, MAX695 V OUT Specified over temperature Low power consumption: 0.7 mW V CC Precision voltage monitor RESET Reset assertion down to 1 V V CC 1 RESET 4.65V 2 GENERATOR Low switch on resistance: 0.7 normal, 7 in backup High current drive: 100 mA WATCHDOG WATCHDOG TRANSITION DETECTOR Watchdog timer: 100 ms, 1.6 sec, or adjustable INPUT (WDI) (1.6sec) ADM8690 Standby current: 400 nA POWER-FAIL Automatic battery backup power switching INPUT (PFI) POWER-FAIL OUTPUT (PFO) Extremely fast gating of chip enable signals (3 ns) 1.3V Voltage monitor for power fail 1 VOLTAGE DETECTOR = 4.65V Available in TSSOP package 2 RESET PULSE WIDTH = 50ms Figure 1. ADM8690 APPLICATIONS Microprocessor systems BATT ON Computers ADM8691/ V Controllers BATT ADM8695 Intelligent instruments V OUT Automotive systems V CC PRODUCT HIGHLIGHTS CE IN CE OUT The ADM8690 is available in 8-lead PDIP and SOIC packages LOW LINE 1 and provides the following functions: 4.65V RESET 1. Power-on reset output during power-up, power-down, OSC IN RESET AND RESET and brownout conditions. The output remains RESET WATCHDOG RESET GENERATOR OSC SEL TIME BASE operational with V as low as 1 V. CC 2. Battery backup switching for CMOS RAM, CMOS micro- WATCHDOG WATCHDOG WATCHDOG WATCHDOG processor, or other low power logic. INPUT (WDI) TRANSITION DETECTOR TIMER OUTPUT (WDO) 3. Reset pulse if the optional watchdog timer is not toggled POWER-FAIL within a specified time. POWER-FAIL INPUT (PFI) OUTPUT (PFO) 1.3V 4. 1.3 V threshold detector for power-fail warning, low battery detection, or to monitor a power supply other than 5 V. 1 VOLTAGE DETECTOR = 4.65V The ADM8691 and ADM8695 are available in 16-lead PDIP Figure 2. ADM8691/ADM8695 and small outline packages (including TSSOP) and 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 VCC status outputs. Rev. C 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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Trademarks and registered trademarks are the property of their respective owners. 00093-002 00093-001ADM8690/ADM8691/ADM8695 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Power-Fail Warning Comparator ............................................. 14 Applications ....................................................................................... 1 Applications Information .............................................................. 15 Product Highlights ........................................................................... 1 Increasing the Drive Current .................................................... 15 Functional Block Diagrams ............................................................. 1 Using a Rechargeable Battery for Backup ............................... 15 Revision History ............................................................................... 2 Adding Hysteresis to the Power-Fail Comparator ................. 15 General Description ......................................................................... 3 Monitoring the Status of the Battery ....................................... 15 Specif icat ions ..................................................................................... 4 Alternate Watchdog Input Drive Circuits ............................... 16 Absolute Maximum Ratings ............................................................ 6 Typical Applications ....................................................................... 17 ESD Caution .................................................................................. 6 ADM8690 Applications ............................................................. 17 Pin Configurations and Function Descriptions ........................... 7 ADM8691/ADM8695 Applications ......................................... 17 Typical Performance Characteristics ............................................. 9 RESET Output ............................................................................ 18 Circuit Information ........................................................................ 11 Power-Fail Detector ................................................................... 18 Battery Switchover Section ........................................................ 11 RAM Write Protection............................................................... 18 RESET Power-Fail Output ......................................................... 11 Watchdog Timer ......................................................................... 18 RESET Outline Dimensions ....................................................................... 19 Watchdog Timer ............................................................ 12 Ordering Guide .......................................................................... 22 Watchdog Output (WDO) (ADM8691/ADM8695) ................. 13 CE Gating and RAM Write Protection (ADM8691/ADM8695) ............................................................. 13 9/06Rev. 0 to Rev. A REVISION HISTORY Updated Format .................................................................. Universal 1 2/11Rev. B to Rev. C Changes to Absolute Maximum Ratings ........................................ 6 Deleted ADM8692 and ADM8693 ............................. Throughout Updated Ordering Guide .............................................................. 20 Changes to Table 4 ............................................................................ 7 RESET Change to Power-Fail Output Section ............................ 11 2/97Revision 0: Initial Version Changes to ADM8691/ADM8695 Applications Section .......... 17 Updated Outline Dimensions ....................................................... 19 Changes to Ordering Guide .......................................................... 22 6/11Rev. A to Rev. B Deleted ADM8694 ......................................................... Throughout Updated Figure 11, Figure 12, and Figure 13 ................................ 9 Updated Outline Dimensions ....................................................... 18 Rev. C Page 2 of 24