The MAX793/MAX794/MAX795 microprocessor (µP) supervisory circuits monitor and control the activities of +3.0V/+3.3V µPs by providing backup-battery switchover, among other features such as low-line indication, µP reset, write protection for CMOS RAM, and a watchdog. The backup-battery voltage can exceed VCC, permitting the use of 3.6V lithium batteries in systems using 3.0V to 3.3V for VCC. The MAX793/MAX795 offer a choice of reset threshold voltage range. The MAX794’s reset threshold is set externally with a resistor divider.
The MAX793, MAX794, and MAX795 are microprocessor supervisory circuits designed for 3.0 V/3.3 V systems. They monitor and control µP activity, provide backup‑battery switchover, low‑line indication, watchdog timer, and CMOS RAM write protection, making them suitable for battery‑powered computers, embedded controllers, and portable equipment.
Key features include selectable reset‑threshold voltage ranges, guaranteed reset assertion to VCC = 1 V, backup‑battery voltage that can exceed VCC, and a variety of output signals (RESET, BATT OK, WATCHDOG, etc.). The datasheet lists absolute maximum ratings, detailed electrical characteristics, pin descriptions, timing diagrams, and guidelines for using the battery freshness seal.
| Supply Voltage Range (VCC) | -0.3 V to +6.0 V |
|---|---|
| Backup Battery Voltage | Can exceed VCC (up to 3.6 V) |
| Continuous Input Current (VCC) | 200 mA |
| Output Current (VOUT) | 200 mA |
The VCC pin can source up to 200 mA continuously.
Yes, the backup battery voltage may exceed VCC, allowing use of 3.6 V lithium batteries.