LM43603 Datasheet, PDF (1/50 Pages) Texas Instruments – LM43603 SIMPLE SWITCHER® 3.5 V to 36 V 3 A Synchronous Step-Down Voltage Converter

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LM43603
SNVSA09B – APRIL 2014 – REVISED SEPTEMBER 2014
LM43603 SIMPLE SWITCHER® 3.5 V to 36 V 3 A Synchronous Step-Down Voltage
Converter
1 Features
•1 27 µA Quiescent Current in Regulation
• High Efficiency at Light Load (DCM and PFM)
• Meets EN55022/CISPR 22 EMI standards
• Integrated Synchronous Rectification
• Adjustable Frequency Range: 200 kHz to 2.2 MHz
(500 kHz default)
• Frequency Synchronization to External Clock
• Internal Compensation
• Stable with Almost Any Combination of Ceramic,
Polymer, Tantalum, and Aluminum Capacitors
• Power-Good Flag
• Soft-Start into a Pre-Biased Load
• Internal Soft-Start: 4.1 ms
• Extendable Soft-Start Time by External Capacitor
• Output Voltage Tracking Capability
• Precision Enable to a Program System UVLO
• Output Short Circuit Protection with Hiccup Mode
• Over Temperature Thermal Shutdown Protection
2 Applications
• Industrial Power Supplies
• Telecommunications Systems
• Sub-AM Band Automotive
• General Purpose Wide V_IN Regulation
• High Efficiency Point-Of-Load Regulation
3 Description
The LM43603 SIMPLE SWITCHER^® regulator is an
easy to use synchronous step-down DC-DC
converter capable of driving up to 3 A of load current
from an input voltage ranging from 3.5 V to 36 V (42V
abs max). The LM43603 provides exceptional
efficiency, output accuracy and dropout voltage in a
very small solution size. An extended family is
available in 0.5 A ,1 A and 2 A load current options in
pin to pin compatible packages. Peak current mode
control is employed to achieve simple control loop
compensation and cycle-by-cycle current limiting.
Optional features such as programmable switching
frequency, synchronization, power-good flag,
precision enable, internal soft-start, extendable soft-
start, and tracking provide a flexible and easy to use
platform for a wide range of applications.
Discontinuous conduction and automatic frequency
modulation at light loads improve light load efficiency.
The family requires few external components and pin
arrangement allows simple, optimum PCB layout.
Protection features include thermal shutdown, V_CC
under-voltage lockout, cycle-by-cycle current limit,
and output short circuit protection. The LM43603
device is available in the HTSSOP / PWP 16 leaded
package (5.1mm x 6.6mm x 1.2mm). Pin to pin
compatible with LM43600, LM43601, LM43602,
LM46000, LM46001, LM46002.
Device Information
ORDER NUMBER
PACKAGE
BODY SIZE
LM43603PWP
HTSSOP (16)
5.1 mm x 6.6 mm
4 Simplified Schematic
V_IN
C_IN
VIN
SW
LM43603
ENABLE
PGOOD
SS/TRK
RT
SYNC
AGND
CBOOT
BIAS
FB
VCC
PGND
L
C_BOOT
V_OUT
C_OUT
C_BIAS
C_FF
R_FBT
C_VCC
R_FBB
C001
LM43603PWPEVM Radiated Emission Graph
12V_IN to 3.3V_OUT, F_S = 500 kHz, I_OUT = 3A
80
Evaluation Board
70
EN 55022 Class B Limit
EN 55022 Class A Limit
60
50
40
30
20
10
0
0
200
400
600
800
1000
Frequency (MHz)
C001
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.