LT8705A - 80V VIN and VOUT Synchronous 4-Switch Buck- Boost DC/DC Controller
Features
- Single Inductor Allows VIN Above, Below, or Equal to Regulated VOUT
- VIN Range 2.8V (Need EXTVCC > 6.4V) to 80V
- VOUT Range: 1.3V to 80V
- Quad N-Channel MOSFET Gate Drivers
- Synchronous Rectification: Up to 98% Efficiency
- Input and Output Current Monitor Pins
- Synchronizable Fixed Frequency: 100kHz to 400kHz
- Integrated Input Current, Input Voltage, Output Current and Output Voltage Feedback Loops
- Improved Light Load Transition from DCM to FCM
- Improved IMON_OUT, IMON_IN Offset When Cold
- Clock Output Usable To Monitor Die Temperature
Typical Application
Description
The LT®8705A is a high performance buck-boost switching regulator controller that operates from input voltages above, below or equal to the output voltage. The part has integrated input current, input voltage, output current and output voltage feedback loops. With a wide 2.8V to 80V input and 1.3V to 80V output range, the LT8705A is compatible with most solar, automotive, telecom and battery-powered systems. The LT8705A is an improved pin compatible version of the LT8705 and is recommended for new designs. See LT8705A vs LT8705 in the Applications Information section for more information.
The LT8705A includes a MODE pin to select among Burst Mode® operation, discontinuous or continuous conduction mode at light loads. Additional features include a 3.3V/12mA LDO, a synchronizable fixed operating frequency, and onboard gate drivers.
| LT8705 | |
| LT8705A | Improved, pin-to-pin compatible version of LT8705. Recommended for all new designs |
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LT8705AEFE#PBF | TSSOP-38 | FE | E | 05-08-1865 | Yes |
| LT8705AEFE#TRPBF | TSSOP-38 | FE | E | 05-08-1865 | Yes |
| LT8705AEUHF#PBF | 5x7 QFN-38 | UHF | E | 05-08-1701 | Yes |
| LT8705AEUHF#TRPBF | 5x7 QFN-38 | UHF | E | 05-08-1701 | Yes |
| LT8705AHFE#PBF | TSSOP-38 | FE | H | 05-08-1865 | Yes |
| LT8705AHFE#TRPBF | TSSOP-38 | FE | H | 05-08-1865 | Yes |
| LT8705AIFE#PBF | TSSOP-38 | FE | I | 05-08-1865 | Yes |
| LT8705AIFE#TRPBF | TSSOP-38 | FE | I | 05-08-1865 | Yes |
| LT8705AIUHF#PBF | 5x7 QFN-38 | UHF | I | 05-08-1701 | Yes |
| LT8705AIUHF#TRPBF | 5x7 QFN-38 | UHF | I | 05-08-1701 | Yes |
| LT8705AMPFE#PBF | TSSOP-38 | FE | MP | 05-08-1865 | Yes |
| LT8705AMPFE#TRPBF | TSSOP-38 | FE | MP | 05-08-1865 | 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 | |
|---|---|---|---|---|---|---|
| LT8705AEFE#PBF | TSSOP-38 | E | $8.50 | $5.95 | Yes | |
| LT8705AEFE#TRPBF | TSSOP-38 | E | $8.56 | $6.01 | Yes | |
| LT8705AEUHF#PBF | 5x7 QFN-38 | E | $8.50 | $5.95 | Yes | |
| LT8705AEUHF#TRPBF | 5x7 QFN-38 | E | $8.56 | $6.01 | Yes | |
| LT8705AHFE#PBF | TSSOP-38 | H | $9.76 | $6.83 | Yes | |
| LT8705AHFE#TRPBF | TSSOP-38 | H | $9.82 | $6.89 | Yes | |
| LT8705AIFE#PBF | TSSOP-38 | I | $9.40 | $6.58 | Yes | |
| LT8705AIFE#TRPBF | TSSOP-38 | I | $9.46 | $6.64 | Yes | |
| LT8705AIUHF#PBF | 5x7 QFN-38 | I | $9.40 | $6.58 | Yes | |
| LT8705AIUHF#TRPBF | 5x7 QFN-38 | I | $9.46 | $6.64 | Yes | |
| LT8705AMPFE#PBF | TSSOP-38 | MP | $25.37 | $17.76 | Yes | |
| LT8705AMPFE#TRPBF | TSSOP-38 | MP | $25.43 | $17.82 | 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
- High Voltage Buck-Boost Converters
- Input or Output Current Limited Converters
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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:
LT8705
LT8705A
LTpowerCAD
The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD
Design tools for the following parts are available in LTpowerCAD:
LT8705
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.