ADVANCE INFORMATION FIRST PAGE OF DATA SHEET IN PREPARATION General Description The MAX790/MAX791 supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery-contro! functions in microprocessor (uP) systems. These include pP reset, backup-battery switchover, watchdog timer, CMOS RAM write protection, and power-failure warning. The RESEToutput of the ICs is guaranteed to be in the correct state for Vcc voltages down to 1V. The MAX790/MAX791 offer several improvements over Maxims MAX690 Series of supervisory circuits, includ- ing 70QpA supply current, 10ns CE propagation delay, 250mA output current (Vcc mode), and 25mA output current (VBATT mode). The MAX790 is pin compatible with the MAX690. Applications Computers Controllers Intelligent Systems Automotive Systems Critical uP Power Monitoring Pin Configurations MA MAL/SVI High-Performance Supervisory Circuits @ Precision 4.72V Monitor @ 250ms RESET Vcc Assertion Time @ 1.6sec or Adjustable Watchdog Timeout Period @ Min Component Count 1A Standby Current # Monitors Backup Battery @ Battery-Backup Power Switching @ On-board Gating of Chip-Enable Signals Features Ordering information PART TEMP. RANGE PIN-PACKAGE MAX790CPA OC to +70C 8 Plastic DIP MAX790C/D 0C to +70C Dice* MAX790EPA -40C to +85C 8 Plastic DIP MAX790MJA -58C to +125C 8 CERDIP MAX791CPE OC to +70C 16 Plastic DIP MAX791CWE -0C to +70C 16 Wide SO MAX791C/D 0C to +70C Dice* MAX791EPE -40C to +85C 16 Plastic DIP MAX791 EWE -40C to +85C 16 Wide SO MAX791MJE -58C to +126C 16 CERDIP Consult factory for dice specifications. TOP VIEW , = vour [1 | 3 | vBATT wel2} trams [7] se Typical Operating Circuit GND (al oO wot yp perating Circu: Pri [4 s | PFO DIP/SO | VW +5V POWER TO uP e Vcc VOUT VBATT RESET CMOS RAM POWER or = WDPO OAT Mi 2 45 = me MAXIMA pP veo Fi] mann ha) w0 = L MAX790 SYSTEM GND [4 | 3] CEIN ofl RESET uP RESET BATT ON [5 | 112] CE our PFO uP NMI PFO [6 i] wo! WO} le- 1/0 PriL?| fo} it 4 GND Ne SET WOT[ a | 9 | MR - LT OIP/SO MAXIL/VI Maxim Integrated Products 5-53 MAxiM is a registered trademark of Maxim Integrated Products. L6ZXVW/O6ZXVIN