Rainbow Electronics MAX742 - Manual

_______________General Description
The MAX742 DC-DC converter is a controller for dual-out-
put power supplies in the 3W to 60W range. Relying on
simple two-terminal inductors rather than transformers, the
MAX742 regulates both outputs independently to within
±4% over all conditions of line voltage, temperature, and
load current.
The MAX742 has high efficiency (up to 92%) over a wide
range of output loading. Two independent PWM current-
mode feedback loops provide tight regulation and opera-
tion free from subharmonic noise. The MAX742 can
operate at 100kHz or 200kHz, so it can be used with small
and lightweight external components. Also ripple and
noise are easy to filter. The MAX742 provides a regulated
output for inputs ranging from 4.2V to 10V (and higher with
additional components).
External power MOSFETs driven directly from the MAX742
are protected by cycle-by-cycle overcurrent sensing. The
MAX742 also features undervoltage lockout, thermal shut-
down, and programmable soft-start.
If 3W of load power or less is needed, refer to the MAX743
data sheet for a device with internal power MOSFETs.
________________________Applications
DC-DC Converter Module Replacement
Distributed Power Systems
Computer Peripherals
____________________________Features
♦ Specs Guaranteed for In-Circuit Performance
♦ Load Currents to ±2A
♦ 4.2V to 10V Input-Voltage Range
♦ Switches From ±15V to ±12V Under Logic Control
♦ ±4% Output Tolerance Max Over Temp, Line,
and Load
♦ 90% Typ Efficiency
♦ Low-Noise, Current-Mode Feedback
♦ Cycle-by-Cycle Current Limiting
♦ Undervoltage Lockout and Soft-Start
♦ 100kHz or 200kHz Operation
MAX742
Switch-Mode Regulator with
+5V to ±12V or ±15V Dual Output
________________________________________________________________ Maxim Integrated Products 1
MAX742
P
R
+5V
INPUT
S
-SENSE
-DRIVE
PWM
N
R
S
+SENSE
+DRIVE
-VO
+VO
PWM
OSC
+2.0V
VREF
CC+
CC-
__________Simplified Block Diagram
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
CSH+
CSL+
GND
EXT+ AV
AGND
CC+
FB+
TOP VIEW
PUMP
PDRV
EXT-
V+ SS
VREF
12/15
100/200
12
11
9
10
CSH-
CSL- FB-
CC-
DIP/SO
MAX742
__________________Pin Configuration
19-3105; Rev 2; 8/96
PART
MAX742 CPP
MAX742CWP
MAX742C/D 0°C to +70°C
0°C to +70°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
20 Plastic DIP
20 Wide SO
Dice*
EVALUATION KIT MANUAL
FOLLOWS DATA SHEET
MAX742EWP
MAX742MJP -55°C to +125°C
-40°C to +85°C 20 Wide SO
20 CERDIP
MAX742EPP -40°C to +85°C 20 Plastic DIP
______________Ordering Information
* Contact factory for dice specifications
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800