MAX5080 Datasheet, PDF (1/19 Pages) Maxim Integrated Products – 1A, 40V, MAXPower Step-Down DC-DC Converters

19-3656; Rev 1; 2/07
1A, 40V, MAXPower Step-Down
DC-DC Converters
General Description
The MAX5080/MAX5081 are 250kHz PWM step-down
DC-DC converters with an on-chip, 0.3Ω high-side
switch. The input voltage range is 4.5V to 40V for the
MAX5080 and 7.5V to 40V for the MAX5081. The output
is adjustable from 1.23V to 32V and can deliver up to
1A of load current.
Both devices utilize a voltage-mode control scheme for
good noise immunity in the high-voltage switching envi-
ronment and offer external compensation allowing for
maximum flexibility with a wide selection of inductor val-
ues and capacitor types. The switching frequency is
internally fixed at 250kHz and can be synchronized to
an external clock signal through the SYNC input. Light
load efficiency is improved by automatically switching
to a pulse-skip mode.
All devices include programmable undervoltage lock-
out and soft-start. Protection features include cycle-by-
cycle current limit, hiccup-mode output short-circuit
protection, and thermal shutdown. Both devices are
available in a space-saving, high-power (2.7W), 16-pin
TQFN package and are rated for operation over the
-40°C to +125°C temperature range.
Applications
FireWire^® Power Supplies
Distributed Power
Automotive
Industrial
FireWire is a registered trademark of Apple Computer, Inc.
V_IN
4.5V TO 40V
Features
♦ 4.5V to 40V (MAX5080) or 7.5V to 40V (MAX5081)
Input Voltage Range
♦ 1A Output Current
♦ V_OUT Range From 1.23V to 32V
♦ Internal High-Side Switch
♦ Fixed 250kHz Internal Oscillator
♦ Automatic Switchover to Pulse-Skip Mode at
Light Loads
♦ External Frequency Synchronization
♦ Thermal Shutdown and Short-Circuit Protection
♦ Operates Over the -40°C to +125°C Temperature
Range
♦ Space-Saving (5mm x 5mm) High-Power 16-Pin
TQFN Package
Ordering Information
PART
TEMP RANGE
MAX5080ATE -40°C to +125°C
MAX5081ATE -40°C to +125°C
*EP = Exposed pad.
PIN-
PACKAGE
16 TQFN-EP*
16 TQFN-EP*
PKG
CODE
T1655-2
T1655-2
Pin Configurations appear at end of data sheet.
Typical Operating Circuits
C_F
D1
R1
C1
IN
REG
DVREG C-
C+
BST
LX
MAX5080
ON/OFF
R2
SYNC SGND PGND
C2
PGND
Typical Operating Circuits continued at end of data sheet.
FB
SS
COMP
C_SS
C_BST
L1
D2
V_OUT
C6
C5
R3
R6
C8
R5
C7
R4
PGND
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