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 monitors the battery voltage
and disconnects the battery from the load if the
battery drops below a set voltage threshold. When
the input battery voltage reaches 500mV above the
set voltage threshold, the load switch turns on and
connects the battery to the load. The 500mV
hysteresis between the Off Mode and the On Mode
prevents intermittent operation.
The voltage threshold (VTHRESH) can be programmed
at manufacturing to a customer-selected set point in
the voltage range of 1.2V to 4.2V in 100mV incre-
ments to support a wide range of applications in con-
sumer, medical, portable, and industrial applications.
This device has ultra-low quiescent current, which
makes it ideal for battery-powered applications.
Typical quiescent current is 100pA in the Off Mode
and 70nA in the On Mode.
The ZSPM4121 includes a slew rate control P-chan-
nel load switch, over-current protection, and an
open-drain power indicator pin (NPG). The slew-rate
controlled turn-on characteristic prevents inrush
current and voltage droop on the voltage. The over-
current limit protects the device in case of an
overload, short-circuit, or ground fault event.
• Best-in-class ultra-low quiescent current in
Off Mode: 100pA (typical)
• Ultra-low quiescent current in On Mode: 70nA
• Accurate on/off voltage threshold
• Low Rds(on): 175mΩ (typical) @ 5V
• Threshold voltage options of 1.2V to 4.2V in
100mV steps (factory programmed)
• Wide input voltage range: 1.2V to 5.5V
• Supervisory over-current limit shutdown: (3A)
• Low drop-out disconnect from VCC to loads
• Controlled turn-on slew rate
• 500mV Off Mode to On Mode hysteresis
Related IDT Smart Power Products
• ZSPM4141 Ultra-Low-Power Linear Regulator
• Evaluation Kit
• Support Documentation
• Package: 8-pin DFN (2mm x 2mm)
ZSPM4121 Block Diagram
© 2016 Integrated Device Technology, Inc.
January 29, 2016