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ZSPM4121 - Application Circuit
ZSPM4121 - Block Diagram
ZSPM4121 - Pinout


Under-Voltage Load Switch for Smart Battery Management

The ZSPM4121 battery management load switch can be used to protect a battery from excessive discharge. It actively switches the battery power source off if it drops to a set threshold (Off Mode). When the input battery voltage is above the threshold, the load switch is on (On Mode). The ZSPM4121 threshold voltage (VTHRESH) is programmed at manufacturing to a set point in the range of 1.2V to 4.2V with 100mV steps between options. When the input battery voltage has been switched off by the ZSPM4121, the quiescent current draw on the battery is in the order of 100pA (typical). The quiescent current in the on state is as low as 70nA. The ZSPM4121 consists of an internally generated threshold voltage, a comparator with hysteresis, slew rate control for the load switch, a P-channel load switch, and an open-drain indicator pin. The 500mV hysteresis between the Off Mode and the On Mode prevents intermittent operation. The ZSPM4121 also provides over-current protection.


  • Power source is actively switched off when VCC drops below a set threshold (programmed at manufacturing)
  • Wide input voltage range: 1.2V to 5.5V
  • Threshold voltage options: 1.2V to 4.2V in 100mV steps (factory programmed)
  • Supervisory over-current limit shutdown
  • Low drop-out disconnect from VCC to loads
  • Controlled turn-on slew rate
  • 500mV Off Mode to On Mode hysteresis
  • Over-current shutdown (3A)

Product Options

Orderable Part IDPart StatusSample & Buy
ZSPM4121AI1W17ActiveCheck Availability
ZSPM4121AI1W21ActiveCheck Availability
ZSPM4121AI1W23ActiveCheck Availability
ZSPM4121AI1W24ActiveCheck Availability
ZSPM4121AI1W25ActiveCheck Availability
ZSPM4121AI1W26ActiveCheck Availability
ZSPM4121AI1W28ActiveCheck Availability
ZSPM4121AI1W30ActiveCheck Availability


Technical Documentation

Title Type Format File Size Datesort icon
Datasheets & Errata
ZSPM4121 Short-form Datasheet Short Form Datasheet PDF 56 KB Jan 29, 2016
ZSPM4121 Datasheet Datasheet PDF 397 KB Jan 29, 2016
User Guides & Manuals
ZSPM4121 Evaluation Kit Description Manual PDF 176 KB Apr 21, 2016
IDT CAD Altium Libraries for AID Products Rev 20160819 PCB Design Files ZIP 1.20 MB Aug 19, 2016