ERROR

AMPLIFIER

Boot

Charge

Boot

UVLO

Oscillator

with PLL

Frequency

Shift

PWM

Control

Logic

Slope

Compensation

PWM

Comparator

Voltage

Reference

FB

VIN

GND

Thermal

Shutdown

EN

Enable

Comparator

Shutdown

Logic

Shutdown

Enable

Threshold

6

Shutdown

OV

Comp

Components

Bootstrap

Control

VIN

UVLO

BOOT

SS

RT/SYNC

SW

LMR14020-Q1

www.ti.com

SNVSAG4 – NOVEMBER 2015

7 Detailed Description

7.1 Overview

from a 4.0 V to 40 V supply voltage. It integrates a 90 m

Ω (typical) high-side MOSFET, and is capable of

delivering up to 2 A DC load current with exceptional efficiency and thermal performance in a very small solution

size. The operating current is typically 40

μA under no load condition (not switching). When the device is

disabled, the supply current is typically 1

μA. An extended family is available in 3.5 A and 5 A load options in pin

to pin compatible packages.

The LMR14020-Q1 implements constant frequency peak current mode control with Sleep-mode at light load to

achieve high efficiency. The device is internally compensated, which reduces design time, and requires fewer

external components. The switching frequency is programmable from 200 kHz to 2.5 MHz by an external resistor

frequency range, which allows the device to be optimized to fit small board space at higher frequency, or high

efficient power conversion at lower frequency.

Other features are included for more comprehensive system requirements, including precision enable, adjustable

soft-start time, and approximate 97% duty cycle by BOOT capacitor recharge circuit. These features provide a

flexible and easy to use platform for a wide range of applications. Protection features include over temperature

and short-circuit protection with frequency fold-back.

7.2 Functional Block Diagram

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Product Folder Links: LMR14020-Q1