4.8A

+

-

COMP

CONTROL

LOGIC

CURRENT

LIMIT

OVERVOLTAGE

UNDERVOLTAGE

ERROR AMP

PWM COMPARATOR

SS/TRK

PGOOD

+

-

+2.7V

REGULATOR

PVIN

PVIN

THERMAL

PROTECTION

PGND

SW

AVIN

CURRENT SENSE

VCC

1.18V

UVLO

2.7V

AGND

OSCILLATOR

+

752 mV

864 mV

PG-L

PG-L

2.7V

5 PA

800 mV

+

-

+

DISCHARGE

DISCHARGE

SLOPE COMP

DIODE

EMULATION

+

-

VREF

+

-

FB

EN

+

-

+

-

(50 Ps)

+

-

+

-

RT

PVIN

LM20143, LM20143-Q1

www.ti.com

SNVS528H – OCTOBER 2007 – REVISED JANUARY 2016

7 Detailed Description

7.1 Overview

The LM20143 switching regulator features all of the functions necessary to implement an efficient low voltage

buck regulator using a minimum number of external components. This easy to use regulator features two

integrated switches and is capable of supplying up to 3 A of continuous output current. The regulator utilizes

peak current mode control with nonlinear slope compensation to optimize stability and transient response over

the entire output voltage range. Peak current mode control also provides inherent line feed-forward, cycle-by-

cycle current limiting and easy loop compensation. The switching frequency can be varied from 500 kHz to 1.5

MHz with an external resistor to ground. The device can operate at high switching frequency allowing use of a

small inductor while still achieving efficiencies as high as 96%. The precision internal voltage reference allows

the output to be set as low as 0.8 V. Fault protection features include: current limiting, thermal shutdown, over

voltage protection, and shutdown capability. The device is available in the HTSSOP 16-pin package featuring an

exposed pad to aid thermal dissipation. The LM20143 can be used in numerous applications to efficiently step-

down from a 5 V or 3.3 V bus. The typical application circuit for the LM20143 is shown in Figure 32 in the design

guide.

7.2 Functional Block Diagram

Copyright © 2007–2016, Texas Instruments Incorporated

Submit Documentation Feedback

11

Product Folder Links: LM20143 LM20143-Q1