19-1744; Rev 0; 7/00
28V Internal Switch LCD Bias Supply
with True Shutdown
General Description
The MAX1606 is a step-up DC-DC converter that con-
tains a 0.5A internal power switch and a 0.5A output
isolation switch in an 8-pin µMAX package. The IC
operates from a 2.4V to 5.5V supply voltage but can
boost battery voltages as low as 0.8V up to 28V.
The MAX1606 uses a unique control scheme that pro-
vides high efficiency over a wide range of load condi-
tions. An internal 0.5A MOSFET reduces external
component count, and a high switching frequency (up
to 500kHz) allows for tiny surface-mount components.
The current limit can be set to 500mA, 250mA, or
125mA, allowing the user to reduce the output ripple
and component size in low-current applications.
Additional features include a low quiescent supply cur-
rent and a true shutdown mode that saves power by
disconnecting the output from the input. The MAX1606
is ideal for small LCD panels with low current require-
ments but can also be used in other applications. A
MAX1606 evaluation kit is available to help speed up
design time.
o
Adjustable Output Voltage up to 28V
o
20mA at 20V from a Single Li+ Battery
o
True Shutdown (Output Disconnected from Input)
o
Output Short-Circuit Protection
o
88% Efficiency
o
Up to 500kHz Switching Frequency
o
Selectable Inductor Current Limit
(125mA, 250mA, or 500mA)
o
0.1µA Shutdown Current
o
8-Pin µMAX Package
Features
MAX1606
________________________Applications
LCD Bias Generators
Cellular or Cordless Phones
Palmtop Computers
Personal Digital Assistants (PDAs)
Organizers
Handy Terminals
PART
MAX1606EUA
Ordering Information
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
8
µMAX
Typical Operating Circuit
Pin Configuration
V
IN
= 0.8V TO 5.5V
SW
BATT
MAX1606
LX
V
OUT
= V
IN
TO 28V
TOP VIEW
BATT
FB
V
CC
GND
1
2
3
4
8
SW
SHDN
LIM
LX
V
CC
= 2.4V TO 5.5V
MAX1606
7
6
5
V
CC
LIM
FB
ON
OFF
SHDN
GND
µMAX
________________________________________________________________
Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.