Microprocessor a Supervisory Circuits ADM690ADM695 FEATURES FUNCTIONAL BLOCK DIAGRAMS Superior Upgrade for MAX690MAX695 V BATT Specified Over Temperature Low Power Consumption (5 mW) V OUT Precision Voltage Monitor V Reset Assertion Down to 1 V V CC CC Low Switch On-Resistance 1.5 V Normal, RESET 20 V in Backup 1 4.65V 2 GENERATOR RESET High Current Drive (100 mA) Watchdog Timer100 ms, 1.6 s, or Adjustable 600 nA Standby Current WATCHDOG WATCHDOG ADM690 TRANSITION DETECTOR Automatic Battery Backup Power Switching INPUT (WDI) (1.6s) ADM692 ADM694 Extremely Fast Gating of Chip Enable Signals (5 ns) POWER FAIL Voltage Monitor for Power Fail INPUT (PFI) POWER FAIL OUTPUT (PFO) APPLICATIONS 1.3V Microprocessor Systems 1 VOLTAGE DETECTOR = 4.65V (ADM690, ADM694) Computers 4.40V (ADM692) Controllers 2 RESET PULSE WIDTH = 50ms (ADM690, ADM692) 200ms (ADM694) Intelligent Instruments BATT ON Automotive Systems V BATT GENERAL DESCRIPTION The ADM690ADM695 family of supervisory circuits offers V OUT complete single chip solutions for power supply monitoring and ADM691 V ADM693 battery control functions in microprocessor systems. These CC ADM695 functions include P reset, backup battery switchover, watchdog CE IN CE OUT timer, CMOS RAM write protection, and power failure warn- LOW LINE ing. The complete family provides a variety of configurations to 1 4.65V satisfy most microprocessor system requirements. RESET The ADM690, ADM692 and ADM694 are available in 8-pin RESET & OSC IN RESET DIP packages and provide: WATCHDOG RESET GENERATOR OSC SEL TIMEBASE 1. Power-on reset output during power-up, power-down and brownout conditions. The RESET output remains opera- WATCHDOG WATCHDOG tional with V as low as 1 V. CC WATCHDOG WATCHDOG TRANSITION DETECTOR TIMER INPUT (WDI) OUTPUT (WDO) 2. Battery backup switching for CMOS RAM, CMOS POWER FAIL microprocessor or other low power logic. INPUT (PFI) POWER FAIL OUTPUT (PFO) 3. A reset pulse if the optional watchdog timer has not been 1.3V toggled within a specified time. 1 VOLTAGE DETECTOR = 4.65V (ADM691, ADM695) 4. A 1.3 V threshold detector for power fail warning, low battery 4.40V (ADM693) detection, or to monitor a power supply other than +5 V. The ADM690ADM695 family is fabricated using an advanced The ADM691, ADM693 and ADM695 are available in 16-pin epitaxial CMOS process combining low power consumption DIP and small outline packages and provide three additional (5 mW), extremely fast Chip Enable gating (5 ns) and high reli- functions. ability. RESET assertion is guaranteed with V as low as 1 V. CC 1. Write protection of CMOS RAM or EEPROM. In addition, the power switching circuitry is designed for mini- 2. Adjustable reset and watchdog timeout periods. mal voltage drop thereby permitting increased output current 3. Separate watchdog timeout, backup battery switchover, and drive of up to 100 mA without the need for an external pass low V status outputs. CC transistor. REV. A Analog Devices, Inc., 1996 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. which may result from its use. No license is granted by implication or Tel: 617/329-4700 Fax: 617/326-8703 otherwise under any patent or patent rights of Analog Devices.(V = Full Operating Range, V = +2.8 V, T = T to CC BATT A MIN ADM690ADM695SPECIFICATIONS T unless otherwise noted) MAX Parameter Min Typ Max Units Test Conditions/Comments BATTERY BACKUP SWITCHING V Operating Voltage Range CC ADM690, ADM691, ADM694, ADM695 4.75 5.5 V ADM692, ADM693 4.5 5.5 V V Operating Voltage Range BATT ADM690, ADM691, ADM694, ADM695 2.0 4.25 V ADM692, ADM693 2.0 4.0 V V Output Voltage V 0.05 V 0.025 V I = 1 mA OUT CC CC OUT V 0.5 V 0.25 V I 100 mA CC CC OUT V in Battery Backup Mode V 0.05 V 0.02 V I = 250 A, V < V 0.2 V OUT BATT BATT OUT CC BATT Supply Current (Excludes I ) 1 1.95 mA I = 100 mA OUT OUT Supply Current in Battery Backup Mode 0.6 1 AV = 0 V, V = 2.8 V CC BATT Battery Standby Current 5.5 V > V > V + 0.2 V CC BATT (+ = Discharge, = Charge) 0.1 +0.02 AT = +25C A 1.0 +0.02 A Battery Switchover Threshold 70 mV Power Up V V 50 mV Power Down CC BATT Battery Switchover Hysteresis 20 mV BATT ON Output Voltage 0.3 V I = 3.2 mA SINK BATT ON Output Short Circuit Current 35 mA BATT ON = V = 4.5 V Sink Current OUT 0.5 1 25 A BATT ON = 0 V Source Current RESET AND WATCHDOG TIMER Reset Voltage Threshold ADM690, ADM691, ADM694, ADM695 4.5 4.65 4.73 V ADM692, ADM693 4.25 4.4 4.48 V Reset Threshold Hysteresis 40 mV Reset Timeout Delay ADM690, ADM691, ADM692, ADM693 35 50 70 ms OSC SEL = HIGH, V = 5 V, T = +25C CC A ADM694, ADM695 140 200 280 ms OSC SEL = HIGH, V = 5 V, T = +25C CC A Watchdog Timeout Period, Internal Oscillator 1.0 1.6 2.25 s Long Period, V = 5 V, T = +25C CC A 70 100 140 ms Short Period, V = 5 V, T = +25C CC A Watchdog Timeout Period, External Clock 3840 4097 Cycles Long Period 768 1025 Cycles Short Period Minimum WDI Input Pulse Width 50 ns V = 0.4, V = 3.5 V IL IH RESET Output Voltage V = +1 V 4 200 mV I = 10 A, V = 1 V CC SINK CC RESET, LOW LINE Output Voltage 0.4 V I = 1.6 mA, V = 4.25 V SINK CC 3.5 V I = 1 A, V = 5 V SOURCE CC RESET, WDO Output Voltage 0.4 V I = 1.6 mA, V = 5 V SINK CC 3.5 V I = 1 A, V = 4.25 V SOURCE CC Output Short Circuit Source Current 1 3 25 A Output Short Circuit Sink Current 25 mA 1 WDI Input Threshold V = 5 V CC Logic Low 0.8 V Logic High 3.5 V WDI Input Current 20 50 A WDI = V , T = +25C OUT A 50 15 A WDI = 0 V, T = +25C A POWER FAIL DETECTOR PFI Input Threshold 1.25 1.3 1.35 V V = +5 V CC PFI Input Current 25 0.01 +25 nA PFO Output Voltage 0.4 V I = 3.2 mA SINK 3.5 V I = 1 A SOURCE PFO Short Circuit Source Current 1 3 25 A PFI = Low, PFO = 0 V PFO Short Circuit Sink Current 25 mA PFI = High, PFO = V OUT CHIP ENABLE GATING CE Threshold 0.8 V V IN IL 3.0 V V IH CE Pull-Up Current 3 A IN CE Output Voltage 0.4 V I = 3.2 mA OUT SINK V 1.5 V I = 3.0 mA OUT SOURCE V 0.05 V I = 1 A, V = 0 V OUT SOURCE CC CE Propagation Delay 5 9 ns REV. A 2