ADVANCE INFORMATION All information in this data sheet is preliminary vz and subject to change. MA AXIASYI 6/95 HP Supervisory Circuit with +1.5% Reset Accuracy General Description Features = The MAX807 microprocessor (uP) supervisory circuit @ Precision 4.675V (MAX807L) or 4.425V reduces the complexity and number of components (MAX807M), or 4.575V (MAX807N) Voltage > needed to monitor power-supply and battery-control func- Monitorin , >< tions in uP systems. A 70UA supply current makes the- 9 MAX807 ideal for use in portable equipment, while a 6ns_ #: 140ms Power OK / Reset Time Delay 5 chip-enable propagation delay and 250mA output current BEGET capability (20mA in battery-backup mode) make it suit- RESET and RESET Outputs N able for larger, higher-performance equipment. @ Independent Watchdog Timer The MAX807 comes in 16-pin DIP and SO packages, and @ 1pA Standby Current provides the following functions: Power Switching: 1) pP reset. The active-low RESET output is asserted dur- 250mA in Vcc Mode ing power-up, power-down, and brownout conditions, and is guaranteed to be in the correct state for Voc 20mA in Battery-Backup Mode down to 1V. @ On-Board Gating of Chip-Enable Signals: 2) Active-high RESET output. Memory Write-Cycle Completion 3) Manual-reset input 6ns CE Gate Propagation Delay 4) Two-stage power-fail warning. A separate low-line * MaxCap and SuperCap Compatible comparator compares Vcc to a threshold 30mV above # Voltage Monitor for Power-Fail or Low-Battery the reset threshold. This low-line comparator is more Warning accurate than those in previous pP supervisors. 5) Backup-battery switchover for CMOS RAM, real-time clocks, Ps, or other low-power logic. Guaranteed RESET Valid to Vcc = 1V 6) Write protection of CMOS RAM or EEPROM. 7) 2.275V threshold detectorprovides for power-fail warning and low-battery detection, or monitors a power supply other than +5V. Pin Configuration oa @ Backup-Battery Monitor 8) BATT OK status flag indicates that the backup-battery voltage is above 2.275V. 9) Watchdog-fault outputasserted if the watchdog input TOP VIEW <I thi i i e has not been toggled within a preset timeout period. PFI i ral VOUT Applications Pro [2 | 15] BATT OK Computers vec 3] anaxcian [14] v8ATt Controllers wol [4] MAx607 fia] BATTON Intelligent Instruments no [| hia] CEN Critical pP Power Monitoring wR [6 fii] cE our Portable/Battery-Powered Equipment FOWUWE [| 10} Woo reser [8 | | 9 | RESET DIP/SO SuperCap is a trademark of Baknor Industries. MaxCap is a trademark of the Carborundum Corp. MAAXISAA Maxim Integrated Products 5-41 Call toll free 1-800-998-8800 for free samples or literature. MAX807 uP Supervisory Circuit with | +1,.5% Reset Accuracy Typical Operating Circuit Ordering Information PART TEMP. RANGE PIN-PACKAGE +5V DN MAX807_CPE OC to +70C 16 Plastic DIP To IF MAX807_CSE OC to +70C 16 Wide SO = AL MAX807_EPE -40C to +85C 16 Plastic DIP Veo BATT VOUT ie MAX807_EWE -40C to +85C 16 Wide SO vBATT ON MAX807_MJE -56C to +126C 16 CERDIP o47HF T xe } This part offers a choice of reset threshold voltage. From the OTHER 14-9 MR COUT table below, select the suffix corresponding to the desired SYSTEM threshold and insert it into the blank to complete the part number. RESET CEIN SOURCES DECODE RESET THRESHOLD (V) MAXIAA SUFFIX PUSH MAX807 AQ-A15 MIN TYP MAX BUTTON fswirce _Wol vO ye L 4.60 4.675 4.76 = LOWE sn NMI N 4.50 4.575 4.65 ~ aESET agSET M 4.35 4.425 4.50 +12V BATT OK > INTERRUPT SUPPLY PFO |} ___ +12V SUPPLY FAILURE PF) WOO | WATCHDOG FAILURE GND MaxCap = = 5-42 PAAXISA