1 Features
1• 33-μA Quiescent Current in Regulation
• High Efficiency at Light Load (DCM and PFM)
• Meets EN55022/CISPR 22 EMI Standards
• Integrated Synchronous Rectification
• Adjustable Frequency Range: 200 kHz to 2.2 MHz
(500 kHz default)
• Frequency Synchronization to External Clock
• Internal Compensation
• Stable With Almost Any Combination of Ceramic,
Polymer, Tantalum, and Aluminum Capacitors
• Power-Good Flag
• Soft Start into Pre-Biased Load
• Internal Soft Start: 4.1 ms
• Extendable Soft-Start Time by External Capacitor
• Output Voltage Tracking Capability
• Precision Enable to Program System UVLO
• Output Short-Circuit Protection With Hiccup Mode
• Overtemperature Thermal Shutdown Protection
• Create a Custom Design Using the LM43601 With
the WEBENCH® Power Designer

2 Applications
• Industrial Power Supplies
• Telecommunications Systems
• Sub-AM Band Automotive
• General Purpose Wide VIN Regulation
• High Efficiency Point-Of-Load Regulation

3 Description
The LM43601 regulator is an easy to use
synchronous step-down DC-DC converter capable of
driving up to 1 A of load current from an input voltage
ranging from 3.5 V to 36 V (42 V transient). The
LM43601 provides exceptional efficiency, output
accuracy, and dropout voltage in a very small solution
size. An extended family is available in 0.5-A, 2-A
and 3-A load current options in pin-to-pin compatible
packages. Peak-current-mode control is employed to
achieve simple control-loop compensation and cycleby-
cycle current limiting. Optional features such as
programmable switching frequency, synchronization,
power-good flag, precision enable, internal soft start,
extendable soft start, and tracking provide a flexible
and easy-to-use platform for a wide range of
applications. Discontinuous conduction and automatic
frequency modulation at light loads improve light load
efficiency. The family requires few external
components and pin arrangement allows simple,
optimum PCB layout. Protection features include
thermal shutdown, VCC undervoltage lockout, cycleby-
cycle current limit, and output short-circuit
protection. The LM43601 device is available in the
16-leaded HTSSOP (PWP) package (6.6 mm × 5.1
mm × 1.2 mm) with 0.65-mm lead pitch. This device
is pin-to-pin compatible with LM46000, LM46001,
LM46002, LM43600, LM43602, and LM43603.