MAX8543-MAX8544 Datasheet, PDF (1/27 Pages) Maxim Integrated Products – Step-Down Controllers with Prebias Startup, Lossless Sensing, Synchronization, and OVP

19-3155; Rev 0; 5/04
EVAALVUAAILTAIOBNLEKIT
Step-Down Controllers with Prebias Startup,
Lossless Sensing, Synchronization, and OVP
General Description
The MAX8543/MAX8544 current-mode, constant-fre-
quency PWM buck controllers operate from a 3V to
13.2V input supply and generate adjustable 0.8V to 0.9
x V_IN output voltages at loads up to 25A. They feature
adjustable switching frequency and synchronization for
noise-sensitive applications.
The MAX8543/MAX8544 can start with (or without) a pre-
existing bias on the output, without discharging the out-
put. This feature simplifies tracking supply designs for
core and I/O applications and redundant supply designs.
The MAX8543/MAX8544 use the DC resistance of the
output inductor as the current-sense element for loss-
less, low-cost current sensing. The current-sense
threshold can be set to four discrete levels to accom-
modate inductors with different DC resistance values.
The MAX8544 features a power-OK monitor and two
MAX8544 controllers that can operate at 180° out-of-
phase for dual-output applications.
Applications
Base Stations
Networks and Telecom
Storage
Servers
Features
♦ Prebias Startup/Monotonic
♦ 1% Output Accuracy
♦ Ceramic, Polymer, or Electrolytic Capacitors
♦ 200kHz to 1MHz Adjustable Frequency
♦ 160kHz to 1.2MHz Synchronization
♦ Lossless, Foldback Current Limit
♦ Overvoltage Protection
♦ Enable (On/Off)
♦ Adjustable Soft-Start
♦ MAX8544
Latch-Off/Autorecovery
Power-OK Monitor
Out-of-Phase Clock Output
Ordering Information
PART
MAX8543EEE
MAX8544EEP
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 QSOP
20 QSOP
Pin Configurations appear at end of data sheet.
Typical Operating Circuit
INPUT 3V TO 13.2V
ON
OFF
OPTIONAL
SYNCHRONIZATION
IN
VL
EN
FSYNC
BST
SS
DH
MAX8543
LX
COMP
DL
ILIM
GND
CS+
PGND
CS-
V_IN = 3V
TO 5.5V
POK (MAX8544)
FB
OUTPUT
0.8V TO 0.9 x V_IN
UP TO 25A
________________________________________________________________ Maxim Integrated Products 1
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