EA

REF

EN/SYNC

SW

CBOOT

VCC

Internal

SS

OV/UV

Detector

Oscillator

Precision

Enable

LDO

PFM

Detector

Slope

Comp

PWM CONTROL LOGIC

UVLO

TSD

Freq

Foldback

Zero

Cross

HICCUP

Detector

VIN

Rc

Cc

PGND

FB

LS I Sense

HS I Sense

FB

VCC

Enable

SYNC

Detector

SYNC Signal

SYNC Signal

AGND

(PGOOD)

Copyright © 2016, Texas Instruments Incorporated

(RT)

11

LMR23630

www.ti.com

SNVSAH2C – DECEMBER 2015 – REVISED JUNE 2017

Product Folder Links: LMR23630

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8 Detailed Description

8.1 Overview

operating from 4.5-V (HSOIC) and 4-V (WSON) to 36-V supply voltage. The device delivers up to 3-A DC load

current with good thermal performance in a small solution size. For both the HSOIC and WSON packages, an

extended family is available in multiple current options from 1 A to 3 A in pin-to-pin compatible packages.

The LMR23630 employs constant frequency peak-current-mode control. The device enters PFM mode at light

load to achieve high efficiency. A user-selectable FPWM version is provided to achieve low output voltage ripple,

tight output voltage regulation, and constant switching frequency. The switching frequency is 400 kHz for the

fixed-frequency version. For the version which has RT pin, the switching frequency is adjustable from 200 kHz to

2.2 MHz. The device is internally compensated, which reduces design time and requires few external

components. The LMR23630 is capable of synchronization to an external clock within the range of 200 kHz to

2.2 MHz.

Additional features such as precision enable, power-good flag, and internal soft-start provide a flexible and easy-

to-use solution for a wide range of applications. Protection features include thermal shutdown, VIN and VCC

undervoltage lockout, cycle-by-cycle current limit, and hiccup-mode short-circuit protection.

The family requires very few external components and has a pinout designed for simple, optimum PCB layout.

8.2 Functional Block Diagram