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.