Protects batteries from excessive discharge
ZSPM4121 battery-management load-switch block diagram
The ZSPM4121 battery-management load switch protects a battery from excessive discharge. It actively switches the battery power source off if the battery voltage drops to a set threshold. When the input battery voltage is above the threshold, the load switch is on. The ZSPM4121 threshold voltage, VTHRESH, is programmed at manufacturing to a set point in the range of 1.2 to 4.2 V with 100 mV steps between options. When the ZSPM4121 disconnects its load from the battery, the IC's quiescent current draw on the battery is in the order of 100 pA. The quiescent current in the on state is as low as 70 nA. The ZSPM4121 integrates a threshold voltage reference, a comparator with hysteresis, slew rate control for the load switch, a P-channel load switch, and an open-drain indicator pin. The 500 mV hysteresis between the off and on modes prevents intermittent operation. The ZSPM4121 also provides over-current protection. Benefits
- Low quiescent current in off mode: 100 pA (typ)
- Low quiescent current in on Mode: 70 nA (typ)
- Accurate threshold voltage
- Low RDS(on): 175 m? (typ) @ 5V
- Power source is actively switched off when VCC drops below factory-set threshold
- Wide input voltage range: 1.2V to 5.5V
- Threshold voltage options of 1.2 V to 4.2 V in 100 mV steps
- Supervisory over-current limit shutdown (3 A)
- Controlled turn-on slew rate
- 500 mV off mode to on mode hysteresis
