LT1173 - Micropower DC/DC Converter Adjustable and Fixed 5V, 12V
Datasheet 
DocumentationDatasheet
Application Note
- AN49 - Illumination Circuitry for Liquid Crystal Displays
- AN51 - Power Conditioning for Notebook and Palmtop Systems
- AN55 - Techniques for 92% Efficient LCD Illumination
- AN65 - A Fourth Generation of LCD Backlight Technology
Design Note
- DN52 - DC-DC Converters for Portable Computers
- DN63 - 2 AA Cells Replace 9V Battery, Extend Operating Life
- DN71 - Regulator Circuit Generates Both 3.3V and 5V Outputs from 3.3V or 5V to Run Computers and RS232
Reliability Data
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Features
- 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
Typical Application
Description
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 quiescent 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.
N-8,SO-8
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LT1173CN8#PBF | PDIP | 8 | C | $2.83 | $2.30 |
| LT1173CN8-12#PBF | PDIP | 8 | C | $2.83 | $2.30 |
| LT1173CN8-5#PBF | PDIP | 8 | C | $2.83 | $2.30 |
| LT1173CS8#PBF | SO | 8 | C | $3.25 | $2.65 |
| LT1173CS8#TRPBF | SO | 8 | C | $2.71 | |
| LT1173CS8-12#PBF | SO | 8 | C | $3.25 | $2.65 |
| LT1173CS8-12#TRPBF | SO | 8 | C | $2.70 | |
| LT1173CS8-5#PBF | SO | 8 | C | $3.25 | $2.65 |
| LT1173CS8-5#TRPBF | SO | 8 | C | $2.71 | |
| LT1173CN8 | PDIP | 8 | C | $5.66 | $4.60 |
| LT1173CN8-12 | PDIP | 8 | C | $5.66 | $4.60 |
| LT1173CN8-5 | PDIP | 8 | C | $5.66 | $4.60 |
| LT1173CS8 | SO | 8 | C | $6.50 | $5.30 |
| LT1173CS8#TR | SO | 8 | C | $5.42 | |
| LT1173CS8-12 | SO | 8 | C | $6.50 | $5.30 |
| LT1173CS8-12#TR | SO | 8 | C | $5.40 | |
| LT1173CS8-5 | SO | 8 | C | $6.50 | $5.30 |
| LT1173CS8-5#TR | SO | 8 | C | $5.42 |
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.