MAX761 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – 12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC Converters

19-0201; Rev 0; 11/93
12V/15V ^{EvaAluvaatiiloanblKeit} or Adjustable, High-Efficiency,
Low I_Q, Step-Up DC-DC Converters
_______________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 110µA 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–MAX773, 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.
_________________________Applications
Flash Memory Programming
PCMCIA Cards
Battery-Powered Applications
High-Efficiency DC-DC Converters
____________________________Features
o High Efficiency for a Wide Range of Load Currents
o 12V/150mA Flash Memory Programming Supply
o 110µA Max Supply Current
o 5µA 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
______________Ordering Information
PART
MAX761CPA
MAX761CSA
MAX761C/D
MAX761EPA
MAX761ESA
MAX761MJA
MAX762CPA
MAX762CSA
MAX762C/D
MAX762EPA
MAX762ESA
MAX762MJA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°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**
* Contact factory for dice specifications.
** Contact factory for availability and processing to MIL-STD-883.
__________Typical Operating Circuit
INPUT
4.75V
TO 12V
33µF
ON/OFF
LX
SHDN ^MAX761 V+
LOW-BATTERY
DETECTOR INPUT
LBI
REF
FB
LBO
GND
18µH
OUTPUT
12V
150mA
33µF
LOW-BATTERY
DETECTOR OUTPUT
__________________Pin Configuration
TOP VIEW
LBO 1
LBI 2
FB 3
SHDN 4
MAX761
MAX762
8 V+
7 LX
6 GND
5 REF
DIP/SO
________________________________________________________________ Maxim Integrated Products 1
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