LT1108 - Micropower DC/DC Converter Adjustable and Fixed 5V, 12V
Features
- Operates at Supply Voltages from 2V to 30V
- Consumes Only 110µA Supply Current
- Works in Step-Up or Step-Down Mode
- Only Four 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 S8 Package
Typical Application
Description
The LT1108 is a versatile micropower DC/DC converter. The device requires only four external components to deliver a fixed output of 5V or 12V. Supply voltage ranges from 2V to 12V in step-up mode and to 30V in step-down mode.The LT1108 functions equally well in step-up,step-down, or inverting applications.The LT1108 is pin-for-pin compatible with the LT1173,but has a duty cycle of 70%, resulting in increased outputcurrent in many applications. The LT1108 can deliver 150mA at 5V from a 2 AA cell input and 5V at 300mA from 9V in step-down mode. Quiescent current is just 110µA,making the LT1108 ideal for power conscious battery-operated systems.
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.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LT1108CN8-12#PBF | N-8 | N | C | 05-08-1510 (N8) | Yes |
| LT1108CN8-5#PBF | N-8 | N | C | 05-08-1510 (N8) | Yes |
| LT1108CN8#PBF | N-8 | N | C | 05-08-1510 (N8) | Yes |
| LT1108CS8-12#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1108CS8-12#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1108CS8-5#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1108CS8-5#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1108CS8#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1108CS8#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LT1108CN8-12#PBF | N-8 | C | $3.00 | $2.45 | Yes | |
| LT1108CN8-5#PBF | N-8 | C | $3.00 | $2.45 | Yes | |
| LT1108CN8#PBF | N-8 | C | $3.00 | $2.45 | Yes | |
| LT1108CS8-12#PBF | SO-8 | C | $3.42 | $2.75 | Yes | |
| LT1108CS8-12#TRPBF | SO-8 | C | $2.81 | Yes | ||
| LT1108CS8-5#PBF | SO-8 | C | $3.42 | $2.75 | Yes | |
| LT1108CS8-5#TRPBF | SO-8 | C | $2.81 | Yes | ||
| LT1108CS8#PBF | SO-8 | C | $3.42 | $2.75 | Yes | |
| LT1108CS8#TRPBF | SO-8 | C | $2.81 | Yes | ||
| Buy Now • Request Samples | ||||||
Demo Boards
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.Click here to view our complete list of demo boards
Applications
- Palmtop Computers
- 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
- Cellular Telephones
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LT1108
LT1108-12
LT1108-5
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
