MAX5090A Datasheet, PDF (1/17 Pages) Maxim Integrated Products – 2A, 76V, High-Efficiency MAXPower Step-Down DC-DC Converters

19-3872; Rev 0; 3/06
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2A, 76V, High-Efficiency
MAXPower Step-Down DC-DC Converters
General Description
The MAX5090A/B/C easy-to-use, high-efficiency, high-
voltage step-down DC-DC converters operate from an
input voltage up to 76V, and consume only 310µA qui-
escent current at no load. This pulse-width-modulated
(PWM) converter operates at a fixed 127kHz switching
frequency at heavy loads, and automatically switches
to pulse-skipping mode to provide low quiescent cur-
rent and high efficiency at light loads. The MAX5090
includes internal frequency compensation simplifying
circuit implementation. The device can also be syn-
chronized with external system clock frequency in a
noise-sensitive application. The MAX5090 uses an
internal low on-resistance and a high-voltage DMOS
transistor to obtain high efficiency and reduce overall
system cost. This device includes undervoltage lock-
out, cycle-by-cycle current limit, hiccup-mode output
short-circuit protection, and overtemperature shutdown.
The MAX5090 delivers up to 2A output current. External
shutdown is included, featuring 19µA (typ) shutdown
current. The MAX5090A/MAX5090B versions have fixed
output voltages of 3.3V and 5V, respectively, while the
MAX5090C features an adjustable 1.265V to 11V output
voltage.
The MAX5090 is available in a space-saving 16-pin thin
QFN package (5mm x 5mm) and operates over the
automotive temperature range (-40°C to +125°C).
Applications
Automotive
Industrial
Distributed Power
Typical Operating Circuit
Features
♦ Wide Input Voltage Range: 6.5V to 76V
♦ Fixed (3.3V, 5V) and Adjustable (1.265V to 11V)
Output-Voltage Versions
♦ 2A Output Current
♦ Efficiency Up to 92%
♦ Internal 0.26Ω High-Side DMOS FET
♦ 310µA Quiescent Current at No Load
♦ 19µA Shutdown Current
♦ Internal Frequency Compensation
♦ Fixed 127kHz Switching Frequency
♦ External Frequency Synchronization
♦ Thermal Shutdown and Short-Circuit Current Limit
♦ -40°C to +125°C Automotive Temperature Range
♦ 16-Pin (5mm x 5mm) Thin QFN Package
♦ Capable of Dissipating 2.67W at +70°C
Ordering Information
PART
TEMP
RANGE
PIN-
PACKAGE*
OUTPUT
VOLTAGE
(V)
MAX5090AATE+ -40°C to +125°C 16 TQFN-EP**
3.3
MAX5090AATE -40°C to +125°C 16 TQFN-EP**
3.3
MAX5090BATE+ -40°C to +125°C 16 TQFN-EP**
5.0
MAX5090BATE -40°C to +125°C 16 TQFN-EP**
5.0
Ordering Information continued at end of data sheet.
*The package code is T1655-3.
**EP = Exposed pad.
+Denotes lead-free package.
Pin Configuration
VIN
7.5V TO 76V
CIN
68µF
CBYPASS
0.47µF
RIN
10Ω
VIN
ON/OFF
DRAIN
LX
MAX5090B ^BST
FB
SS
SYNC
VD
SGND PGND
CBST
0.22µF
100µH
D1
PDS5100H
3.3µF
CSS
0.047µF
VOUT
5V/2A
COUT
100µF
TOP VIEW
12 11 10 9
DRAIN 13
DRAIN 14
N.C. 15
N.C. 16
EP
MA5090
1
2
3
4
8 FB
7 SS
6 SYNC
5 VD
TQFN
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