X40420
Dual Voltage Monitor with Integrated CPU Supervisor and System Battery Switch
Key Features
- Dual voltage detection and reset assertion
- Three standard reset threshold settings (4.6V/2.9V, 4.6V/2.6V, 2.9V/1.6V)
- VTRIP2 programmable down to 0.9V
- Adjust low voltage reset threshold voltages using special programming sequence
- Reset signal valid to VCC = 1V
- Monitor two voltages or detect power fail
- Battery switch backup
- VOUT: 5mA to 50mA from VCC; or 250µA from VBATT
- Fault detection register
- Selectable power-on reset timeout (0.05s, 0.2s, 0.4s, 0.8s)
- Selectable watchdog timer interval (25ms, 200ms, 1.4s, off)
- Debounced manual reset input
- Low power CMOS
- 25µA typical standby current, watchdog on
- 6µA typical standby current, watchdog off
- 1µA typical battery current in backup mode
- 4Kbits of EEPROM
- 16 byte page write mode
- Self-timed write cycle
- 5ms write cycle time (typical)
- Built-in inadvertent write protection
- Power-up/power-down protection circuitry
- Block lock protect 0 or 1/2, of EEPROM
- 400kHz 2-wire interface
- 2.7V to 5.5V power supply operation
- Monitor voltages: 5V to 1.6V
- Memory security
- Battery switch backup
- VOUT 5mA to 50mA
- Available packages
- 14 Ld SOIC, TSSOP
- Pb-free plus anneal available (RoHS compliant)
Description
The X40420, X40421 combines power-on reset control, watchdog timer, supply voltage supervision, and secondary supervision, manual reset, and Block Lock™ protect serial EEPROM in one package. This combination lowers system cost, reduces board space requirements, and increases reliability.
Applying voltage to VCC activates the power-on reset circuit which holds RESET/RESET active for a period of time. This allows the power supply and system oscillator to stabilize before the processor can execute code.
Applications
- Communications equipment
- Routers, hubs, switches
- Disk arrays
- Industrial systems
- Process control
- Intelligent instrumentation
- Computer systems
- Desktop computers
- Network servers


