MAX690MAX695 Microprocessor Supervisory Circuits General Description Benefits and Features The MAX690 family of supervisory circuits reduces the Supervisory Function Integration Saves Board Space complexity and number of components required for while Fully Protecting Microprocessor-Based Systems power supply monitoring and battery control functions in Precision Voltage Monitor microprocessor systems. These include P reset and - 4.65V (MAX690, MAX691, MAX694, MAX695) backup-battery switchover, watchdog timer, CMOS RAM - 4.40V (MAX692, MAX693) write protection, and power-failure warning. The MAX690 Power OK/Reset Time Delay family significantly improves system reliability and accu- - 50ms, 200ms, or Adjustable racy compared to that obtainable with separate ICs or Watchdog Timer discrete components. - 100ms, 1.6s, or Adjustable Battery Backup Power Switching The MAX690, MAX692, and MAX694 are supplied in Voltage Monitor for Power Fail or Low Battery 8-pin packages and provide four functions: Warning A reset output during power-up, power-down, and Minimum External Component Count brownout conditions. Low Power Consumption in Battery Backup Mode Battery backup switching for CMOS RAM, CMOS Extends Battery Life microprocessor or other low power logic. 1A Standby Current A Reset pulse if the optional watchdog timer has not Onboard Gating of Chip Enable Signals Protects been toggled within a specified time. Against Erroneous Data Written to RAM During Low A 1.3V threshold detector for power fail warning, low V Events CC battery detection, or to monitor a power supply other Applications than +5V. Computers The MAX691, MAX693, and MAX695 are supplied in 16-pin Controllers packages and perform all MAX690, MAX692, MAX694 Intelligent Instruments functions, plus: Automotive Systems Write protection of CMOS RAM or EEPROM. Critical P Power Monitoring Adjustable reset and watchdog timeout periods. Ordering information appears at end of data sheet. Separate outputs for indicating a watchdog timeout, backup-battery switchover, and low V . Pin Configurations CC TOP VIEW V 1 8 V OUT BATT Typical Operating Circuit MAX690 V 2 7 RESET CC MAX692 MAX694 GND 3 6 WDI PFI 4 5 PFO +5V V V POWER TO P CC OUT CMOS RAM POWER V BATT V 1 16 RESET BATT P VOUT 2 15 RESET MAX690 SYSTEM V 3 14 WDO CC MAX691 RESET P RESET MAX693 PFI GND 4 13 CE IN MAX695 PFO P NMI BATT ON 5 12 CE OUT WDI I/O LOW LINE 6 11 WDI LINE GND OSC IN 7 10 PFO OSC SEL 8 9 PFI MAX690 TYPICAL APPLICATION 19-0218 Rev 5 4/15MAX690MAX695 Microprocessor Supervisory Circuits Absolute Maximum Ratings Terminal Voltage (with respect to GND) Power Dissipation V ...................................................................-0.3V to +6.0V 8-Pin Plastic DIP CC V ...............................................................-0.3V to +6.0V (derate 5mW/C above +70C) ....................................400mV BATT All Other Inputs (Note 1) ................... -0.3V to (V + 0.5V) 8-Pin CERDIP OUT Input Current (derate 8mW/C above +85C) ....................................500mV V ...............................................................................200mA 16-Pin Plastic DIP CC V .............................................................................50mA (derate 7mW/C above +70C) ....................................600mV BATT GND ...............................................................................20mA 16-Pin Small Outline Output Current (derate 7mW/C above +70C) ....................................600mV V .....................................................Short circuit protected 16-Pin CERDIP OUT All Other Outputs ............................................................20mA (derate 10mW/C above +85C) ..................................600mV Rate-of-Rise, V , V ..............................................100V/s Storage Temperature Range ............................ -65C to +160C BATT CC Operating Temperature Range Lead Temperature (Soldering, 10s) ...................................300C C suffix ................................................................0C to +70C E suffix ............................................................ -40C to +85C M suffix ......................................................... -55C to +125C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics V = full operating range, V = 2.8V, T = +25C, unless otherwise noted.) CC BATT A PARAMETER CONDITIONS MIN TYP MAX UNITS BATTERY BACKUP SWITCHING Operating Voltage Range 4.75 5.5 (MAX690, MAX691, MAX694, MAX695 V ) CC Operating Voltage Range (MAX690, MAX691, 2.0 4.25 MAX694, MAX695 V ) BATT V Operating Voltage Range 4.5 5.5 (MAX692, MAX693 V ) CC Operating Voltage Range 2.0 4.0 (MAX692, MAX693 V ) BATT V - V - CC CC I = 1mA OUT 0.3 0.1 V Output Voltage V OUT V - V - CC CC I = 50mA OUT 0.5 0.25 V V BATT BATT V in Battery Backup Mode I = 250A, V < V - 0.2V V OUT OUT CC BATT - 0.1 - 0.02 I = 1mA 2 5 OUT Supply Current (Excluded I ) mA OUT I = 50mA 3.5 10 OUT Supply Current in Battery Backup Mode V = 0V, V = 2.8V 0.6 1 A CC BATT T = +25C -0.1 +0.02 A Battery Standby Current 5.5V > V > CC A T = full operating A (+ = Discharge, - = Charge) V + 1V BATT -1.0 +0.02 range Power-up 70 Battery Switchover Threshold mV (V - V ) CC BATT Power-down 50 Maxim Integrated 2 www.maximintegrated.com