Texas Instruments LM2854-1000 - 1 MHz Buck Regulator LM2854-1000EVAL LM2854-1000EVAL 데이터 시트
제품 코드
LM2854-1000EVAL
PVIN
AVIN
EN
AGND
PGND
FB
SW
LM2854
V
IN
V
OUT
SS
C
IN
L
O
C
O
R
FB1
R
COMP
C
COMP
R
FB2
C
SS
User's Guide
SNVA358B – August 2008 – Revised May 2013
AN-1880 LM2854 1MHz Buck Regulator Demo Board
1
Introduction
The LM2854 PowerWise™ SIMPLE SWITCHER
®
buck regulator demonstration board is a 1 MHz step-
down voltage regulator capable of driving 0A up to 4A load current with excellent power conversion
efficiency. A typical schematic of an LM2854 application is given in
efficiency. A typical schematic of an LM2854 application is given in
. The LM2854 pin-out and pin
description are given in
The LM2854 demonstration board is designed to accept an input voltage rail between 2.95V and 5.5V and
deliver a fixed and highly accurate output voltage of 1.2V. The output voltage level can be changed by
modification of one feedback resistor value. Externally established soft-start with a small value
capacitance facilitates a controlled, well-defined and monotonic start-up output voltage characteristic. In
addition, the LM2854 is capable of starting monotonically and glitch free into a pre-biased load.
deliver a fixed and highly accurate output voltage of 1.2V. The output voltage level can be changed by
modification of one feedback resistor value. Externally established soft-start with a small value
capacitance facilitates a controlled, well-defined and monotonic start-up output voltage characteristic. In
addition, the LM2854 is capable of starting monotonically and glitch free into a pre-biased load.
With some of the required voltage loop compensation components integrated in the regulator, the number
of external passive components and PC board area typically necessary in a voltage mode buck converter
application are reduced. An LM2854 based regulator design with type III loop compensation can be
implemented with as few as eight external components. Only two small size external compensation
components are required, similar to that commonly involved with current mode control compensation.
Unlike a compensation solution where all the compensation components are integrated, the LM2854 has
the flexibility to deal with ceramic and/or electrolytic based load capacitance spanning a wide range of
capacitor values.
of external passive components and PC board area typically necessary in a voltage mode buck converter
application are reduced. An LM2854 based regulator design with type III loop compensation can be
implemented with as few as eight external components. Only two small size external compensation
components are required, similar to that commonly involved with current mode control compensation.
Unlike a compensation solution where all the compensation components are integrated, the LM2854 has
the flexibility to deal with ceramic and/or electrolytic based load capacitance spanning a wide range of
capacitor values.
Lossless cycle-by-cycle peak current limit is used to protect the load from an overcurrent or short-circuit
fault, and an enable comparator permits system sequencing or increase of the input UVLO above the
nominal 2.7V level. The device is available in a power enhanced HTSSOP-16 package featuring an
exposed die attach pad that improves the thermal performance of the regulator.
fault, and an enable comparator permits system sequencing or increase of the input UVLO above the
nominal 2.7V level. The device is available in a power enhanced HTSSOP-16 package featuring an
exposed die attach pad that improves the thermal performance of the regulator.
Figure 1. Typical System Application Using LM2854 Synchronous Buck Regulator
PowerWise is a trademark of Texas Instruments.
SIMPLE SWITCHER is a registered trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
SIMPLE SWITCHER is a registered trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
1
SNVA358B – August 2008 – Revised May 2013
AN-1880 LM2854 1MHz Buck Regulator Demo Board
Copyright © 2008–2013, Texas Instruments Incorporated