Rainbow Electronics MAX5090C - Manual

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
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
MAX5090A/B/C
2A, 76V, High-Efficiency MAXPower Step-Down
DC-DC Converters
________________________________________________________________ Maxim Integrated Products 1
15
16
14
13
6
5
7
LX V IN
8
LX
N.C. ON/OFF PGND
1 2
DRAIN
4
12
EP
11 9
N.C.
N.C.
FB
SS
SYNC
VD
MA5090
BST
SGND
3
10
DRAIN
TQFN
TOP VIEW
Pin Configuration
PGND
BST
LX
V IN
SGND
FB
V OUT
5V/2A
VD
100 µH
C BST
0.22 µF
3.3 µF
ON/OFF C OUT
100 µF
SS
SYNC
D1
PDS5100H
DRAIN
C SS
0.047 µF
C IN
68 µF C BYPASS
0.47 µF
R IN
10 Ω
VIN
7.5V TO 76V
MAX5090B
Typical Operating Circuit
19-3872; Rev 0; 3/06
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.
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
Ordering Information continued at end of data sheet.
*The package code is T1655-3.
**EP = Exposed pad.
+Denotes lead-free package.