Rainbow Electronics MAX5081 - Manual

General Description
The MAX5080/MAX5081 are 250kHz PWM step-down
DC-DC converters with an on-chip, 0.3
Ω 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 Automotive
Distributed Power Industrial
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
MAX5080/MAX5081
1A, 40V, MAXPower Step-Down
DC-DC Converters
________________________________________________________________ Maxim Integrated Products 1
19-3656; Rev 0; 5/05
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX5080ATE -40°C to +125°C 16 TQFN-EP*
MAX5081ATE -40°C to +125°C 16 TQFN-EP*
MAX5080
V IN
4.5V TO 40V
ON/OFF
C1
R1
R2
C2
PGND
REG
LX
FB
IN
SYNC SGND PGND SS COMP
DVREG C-
C F
V OUT
PGND
C BST
C SS
D1
D2
L1
C8
C5
R6
R5
C+ BST
C7
C6
R3
R4
Typical Operating Circuits
FireWire is a registered trademark of Apple Computer, Inc.
Typical Operating Circuits continued at end of data sheet.
*EP = Exposed pad.
Pin Configurations appear at end of data sheet.