Texas Instruments SIMPLE SWITCHER® 42V, 0.5A Step-Down Switching Regulator LM25574BLDT LM25574BLDT Datenbogen
Produktcode
LM25574BLDT
Rfb1
BST
SW
COMP
FB
SS
RAMP
RT
VCC
VIN
OUT
IS
PGND
LM(2)5574
INPUT
OUTPUT
SD
SYNC
Ccomp
C
RAMP
C3
Cbyp
Cboot
Cin
Cout
Css
Rt
1
2
3
4
5
6
7
8
AGND
9
10
12
13
14
15
16
PRE
Rcomp
11
C4
R3
C7
C5
R4
C6
C2
D1
L1
R1
Rfb2
R2
C1
Introduction
1
Introduction
The LM5574 and LM25574 switching regulators feature all of the functions necessary to implement an
efficient high voltage buck regulator using a minimum of external components. These easy to use
regulators include either a 42V (LM25574) or a 75V (LM5574) N-Channel buck switch with an output
current capability of 0.5 Amps. The operating frequency is programmable from 50kHz up to 1MHz.
Protection features include: current limit, thermal shutdown and remote shutdown capability. The device is
available in a TSSOP-16 package. More detailed information including theory of operation, design trade-
offs and additional application guidance is available in the device datasheet. Shown below in
efficient high voltage buck regulator using a minimum of external components. These easy to use
regulators include either a 42V (LM25574) or a 75V (LM5574) N-Channel buck switch with an output
current capability of 0.5 Amps. The operating frequency is programmable from 50kHz up to 1MHz.
Protection features include: current limit, thermal shutdown and remote shutdown capability. The device is
available in a TSSOP-16 package. More detailed information including theory of operation, design trade-
offs and additional application guidance is available in the device datasheet. Shown below in
is a
complete schematic for a 0.5 Amp step-down DC-DC converter. Several external component values can
be standardized for most applications. The input voltage range, output voltage and desired operating
frequency dictate the remaining component values.
be standardized for most applications. The input voltage range, output voltage and desired operating
frequency dictate the remaining component values.
An Excel based spreadsheet derived from the guide is available on
Figure 1. Application Schematic
2
AN-1563 Quick Start Guide for a 0.5 Amp Buck Regulator Using The
SNVA206B – January 2007 – Revised April 2013
LM5574 and LM25574
Copyright © 2007–2013, Texas Instruments Incorporated