EVALUATION KIT AVAILABLE
MAX1771
12V or Adjustable, High-Efficiency,
Low I , Step-Up DC-DC Controller
Q
General Description
Features
The MAX1771 step-up switching controller provides
90% efficiency over a 30mA to 2A load. A unique cur-
rent-limited pulse-frequency-modulation (PFM) control
scheme gives this device the benefits of pulse-width-
modulation (PWM) converters (high efficiency at heavy
loads), while using less than 110µA of supply current (vs.
2mA to 10mA for PWM converters).
ꢀ 90% Efficiency for 30mA to 2A Load Currents
ꢀ Up to 24W Output Power
ꢀ 110µA (max) Supply Current
ꢀ 5µA (max) Shutdown Current
ꢀ 2V to 16.5V Input Range
This controller uses miniature external components. Its
high switching frequency (up to 300kHz) allows sur-
face-mount magnetics of 5mm height and 9mm diame-
ter. It accepts input voltages from 2V to 16.5V. The
output voltage is preset at 12V, or can be adjusted
using two resistors.
ꢀ Preset 12V or Adjustable Output Voltage
ꢀ Current-Limited PFM Control Scheme
ꢀ Up to 300kHz Switching Frequency
ꢀ Evaluation Kit Available
The MAX1771 optimizes efficiency at low input voltages
and reduces noise by using a single 100mV current-limit
threshold under all load conditions. A family of similar
devices, the MAX770–MAX773, trades some full-load
efficiency for greater current-limit accuracy; they provide
a 200mV current limit at full load, and switch to 100mV
for light loads.
Ordering Information
PART
TEMP RANGE
0°C to +70°C
PIN-PACKAGE
8 Plastic DIP
8 SO
MAX1771CPA
MAX1771CSA
MAX1771C/D
MAX1771EPA
MAX1771ESA
MAX1771MJA
The MAX1771 drives an external N-channel MOSFET
switch, allowing it to power loads up to 24W. If less power
is required, use the MAX756/MAX757 or MAX761/MAX762
step-up switching regulators with on-board MOSFETs. An
evaluation kit is available.
0°C to +70°C
0°C to +70°C
Dice*
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
8 Plastic DIP
8 SO
Applications
8 CERDIP**
* Contact factory for dice specifications.
** Contact factory for availability and processing to MIL-STD-883B.
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Pin Configuration
Typical Operating Circuit
TOP VIEW
INPUT
2V TO V
OUT
OUTPUT
12V
1
2
3
4
8
7
6
5
EXT
V+
CS
N
EXT
CS
GND
AGND
MAX1771
MAX1771
ON/OFF
SHDN
FB
REF
SHDN
REF
V+
DIP/SO
FB AGND GND
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-0263; Rev 2; 3/02