19-0201; Rev 0; 11/93
Kit
tion e
lua
l
Eva vailab
A
12V/15V or Adjustable, High-Efficiency,
Low I
Q
, Step-Up DC-DC Converters
____________________________Features
o
High Efficiency for a Wide Range of Load Currents
o
12V/150mA Flash Memory Programming Supply
o
110碌A Max Supply Current
o
5碌A Max Shutdown Supply Current
o
2V to 16.5V Input Voltage Range
o
12V (MAX761), 15V (MAX762) or Adjustable Output
o
Current-Limited PFM Control Scheme
o
300kHz Switching Frequency
o
Internal, 1A, N-Channel Power FET
o
LBI/LBO Low-Battery Comparator
_______________General Description
The MAX761/MAX762 step-up switching regulators
provide high efficiency over a wide range of load currents,
delivering up to 150mA. A unique, current-limited
pulse-frequency-modulated (PFM) control scheme gives
the devices the benefits of pulse-width-modulated (PWM)
converters (high efficiency with heavy loads), while using
less than 110碌A of supply current (vs. 2mA to 10mA for
PWM converters). The result is high efficiency over a wide
range of loads.
The MAX761/MAX762 input voltage range is 2V to 16.5V.
Output voltages are preset to 12V (MAX761) and 15V
(MAX762), or they can be set with two external resistors.
With a 5V input, the MAX761 guarantees a 12V, 150mA
output. Its high efficiency, low supply current, fast start-up
time, SHDN controlling capability, and small size make the
MAX761 ideal for powering flash memory.
The MAX761/MAX762 have an internal 1A power MOS-
FET, making them ideal for minimum-component, low- and
medium-power applications. These devices use tiny exter-
nal components, and their high switching frequencies (up
to 300kHz) allow for small surface-mount magnetics.
For increased output drive capability or higher output volt-
ages, use the MAX770鈥揗AX773, which are similar in
design to the MAX761/MAX762, but drive external power
MOSFETs. For stepping up to 5V, see the MAX756/
MAX757 and MAX856-MAX859 data sheets.
MAX761/MAX762
______________Ordering Information
PART
MAX761CPA
MAX761CSA
MAX761C/D
MAX761EPA
MAX761ESA
MAX761MJA
MAX762CPA
MAX762CSA
MAX762C/D
MAX762EPA
MAX762ESA
MAX762MJA
TEMP. RANGE
0掳C to +70掳C
0掳C to +70掳C
0掳C to +70掳C
-40掳C to +85掳C
-40掳C to +85掳C
-55掳C to +125掳C
0掳C to +70掳C
0掳C to +70掳C
0掳C to +70掳C
-40掳C to +85掳C
-40掳C to +85掳C
-55掳C to +125掳C
PIN-PACKAGE
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 CERDIP**
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 CERDIP**
_________________________Applications
Flash Memory Programming
PCMCIA Cards
Battery-Powered Applications
High-Efficiency DC-DC Converters
* Contact factory for dice specifications.
** Contact factory for availability and processing to MIL-STD-883.
__________Typical Operating Circuit
INPUT
4.75V
TO 12V
__________________Pin Configuration
TOP VIEW
33碌F
18碌H
LX
OUTPUT
12V
150mA
33碌F
LBO
LBI
FB
1
2
3
8
V+
LX
GND
REF
ON/OFF
MAX761
SHDN
LBI
V+
MAX761
MAX762
7
6
5
LOW-BATTERY
DETECTOR INPUT
LBO
REF
FB
GND
LOW-BATTERY
DETECTOR OUTPUT
SHDN
4
DIP/SO
________________________________________________________________
Maxim Integrated Products
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Call toll free 1-800-998-8800 for free samples or literature.
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