Datasheet

LT1173
1
Micropower
DC/DC Converter
Adjustable and Fixed 5V, 12V
V
OUT
5V/DIV
0V
PROGRAM
5V/DIV
5ms/DIV
1173 TA02
L1*
100µH
LT1173 • TA01
+
GND SW2
FB
SW1
LIM
I
IN
V
LT1173
10 F
SANYO
OS-CON
100 F
µ
12V
100mA
1N5818
µ
+
5V
IN
1N4148
PROGRAM
47
*L1 = GOWANDA GA20-103K
COILTRONICS CTX100-4
1.07M
124k
NO OVERSHOOT
EFFICIENCY = 81%
= 1% METAL FILM
Logic Controlled Flash Memory VPP Generator
VPP Output
D
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and LTC are registered trademarks and LT is a trademark of Linear Technology Corporation.
Operates at Supply Voltages From 2.0V to 30V
Consumes Only 110µA Supply Current
Works in Step-Up or Step-Down Mode
Only Three External Components Required
Low Battery Detector Comparator On-Chip
User-Adjustable Current Limit
Internal 1A Power Switch
Fixed or Adjustable Output Voltage Versions
Space Saving 8-Pin MiniDIP or SO8 Package
The LT1173 is a versatile micropower DC-DC converter.
The device requires only three external components to
deliver a fixed output of 5V or 12V. Supply voltage ranges
from 2.0V to 12V in step-up mode and to 30V in step-down
mode. The LT1173 functions equally well in step-up, step-
down or inverting applications.
The LT1173 consumes just 110µA supply current at
standby, making it ideal for applications where low quies-
cent current is important. The device can deliver 5V at
80mA from a 3V input in step-up mode or 5V at 200mA
from a 12V input in step-down mode.
Switch current limit can be programmed with a single
resistor. An auxiliary gain block can be configured as a low
battery detector, linear post regulator, under voltage lock-
out circuit or error amplifier.
For input sources of less than 2V, use the LT1073.
Flash Memory Vpp Generators
3V to 5V, 5V to 12V Converters
9V to 5V, 12V to 5V Converters
LCD Bias Generators
Peripherals and Add-On Cards
Battery Backup Supplies
Laptop and Palmtop Computers
Cellular Telephones
Portable Instruments
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