1FEATURES
2• LM20125Q is AEC-Q100 Qualified and
Manufactured on an Automotive Grade Flow
• Input Voltage Range 2.95V to 5.5V
• Accurate Current Limit Minimizes Inductor
Size
• 97% Efficiency with 500 kHz Switching
Frequency
• 32 mΩ Integrated FET Switches
• Starts up into Pre-Biased Loads
• Output Voltage Tracking
• Peak Current Mode Control
• Adjustable Output Voltage Down to 0.8V
• Adjustable Soft-Start with External Capacitor
• Precision Enable Pin with Hysteresis
• Integrated OVP, UVLO, Power Good and
Thermal Shutdown
• HTSSOP 16-Pin Exposed Pad Package

APPLICATIONS
• Simple to Design, High Efficiency Point of
Load Regulation from a 5V or 3.3V Bus
• High Performance DSPs, FPGAs, ASICs and
Microprocessors
• Broadband, Networking and Optical
Communications Infrastructure

DESCRIPTION
The LM20125 is a full featured 500 kHz synchronous
buck regulator capable of delivering up to 5A of
continuous output current. The current mode control
loop can be compensated to be stable with virtually
any type of output capacitor. For most cases,
compensating the device only requires two external
components, providing maximum flexibility and ease
of use. The device is optimized to work over the input
voltage range of 2.95V to 5.5V making it suited for a
wide variety of low voltage systems.
The device features internal over voltage protection
(OVP) and over current protection (OCP) circuits for
increased system reliability. A precision enable pin
and integrated UVLO allows the turn-on of the device
to be tightly controlled and sequenced. Start-up
inrush currents are limited by both an internally fixed
and externally adjustable Soft-Start circuit. Fault
detection and supply sequencing is possible with the
integrated power good circuit.
The LM20125 is designed to work well in multi-rail
power supply architectures. The output voltage of the
device can be configured to track a higher voltage rail
using the SS/TRK pin. If the output of the LM20125 is
pre-biased at startup it will not sink current to pull the
output low until the internal soft-start ramp exceeds
the voltage at the feedback pin.
The LM20125 is offered in a 16-pin HTSSOP
package with an exposed pad that can be soldered to
the PCB, eliminating the need for bulky heatsinks.