Power Management
Switching Regulator
Step-Down (Buck) Regulators
High Input Voltage Buck
Power Management
Switching Regulator
Step-Down (Buck) Regulators
External Power Switch Buck Controllers
Space & Harsh Environment
Extended Temperature Plastic (H & MP)
Extended Temperature (H & MP) Switching Regulators
LT3845 - High Voltage Synchronous Current Mode Step-Down Controller with Adjustable Operating Frequency
Features
- High Voltage Operation: Up to 60V
- Synchronizable Up to 600kHz
- Adjustable Constant Frequency: 100kHz to 500kHz
- Output Voltages Up to 36V
- Adaptive Nonoverlap Circuitry Prevents Switch Shoot-Through
- Reverse Inductor Current Inhibit for Discontinuous Operation Improves Efficiency with Light Loads
- Programmable Soft-Start
- 120μA No Load Quiescent Current
- 10μA Shutdown Supply Current
- 1% Regulation Accuracy
- Standard Gate N-Channel Power MOSFETs
- Current Limit Unaffected by Duty Cycle
- Reverse Overcurrent Protection
- 16-Lead Thermally Enhanced TSSOP Package, 16-Pin PDIP
Typical Application
Description
The LT3845 is a high voltage, synchronous, current mode controller used for medium to high power, high efficiency supplies. It offers a wide 4V to 60V input range (7.5V minimum start-up voltage). An onboard regulator simplifies the biasing requirements by providing IC power directly from VIN.
Burst Mode operation maintains high efficiency at light loads by reducing IC quiescent current to 120μA. Light load efficiency is also improved with the reverse inductor current inhibit function which supports discontinuous operation.
Additional features include adjustable fixed operating frequency that can be synchronized to an external clock for noise sensitive applications, gate drivers capable of driving large N-channel MOSFETs, a precision undervoltage lockout, 10μA shutdown current, short-circuit protection and a programmable soft-start.
The LT3845 is available in a 16-lead thermally enhanced TSSOP package and 16-pin through hole N package.
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
TSSOP-16E
Order Info
- Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
- 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 | Pins | Temp | Price (1-99) | Price (1k)* | RoHS Data |
|---|---|---|---|---|---|---|
| LT3845AEFE#PBF | TSSOP | 16 | E | $5.09 | $3.56 | View |
| LT3845AEFE#TRPBF | TSSOP | 16 | E | $3.62 | View | |
| LT3845AIFE#PBF | TSSOP | 16 | I | $5.89 | $4.12 | View |
| LT3845AIFE#TRPBF | TSSOP | 16 | I | $4.18 | View | |
| LT3845AMPFE#PBF | TSSOP | 16 | MP | $15.22 | $10.65 | View |
| LT3845AMPFE#TRPBF | TSSOP | 16 | MP | $10.71 | View | |
| LT3845EFE#PBF | TSSOP | 16 | E | $5.09 | $3.56 | View |
| LT3845EFE#TRPBF | TSSOP | 16 | E | $3.62 | View | |
| LT3845EN#PBF | PDIP | 16 | E | $5.09 | $3.56 | View |
| LT3845IFE#PBF | TSSOP | 16 | I | $6.00 | $4.20 | View |
| LT3845IFE#TR | TSSOP | 16 | I | $4.26 | View | |
| LT3845IFE#TRPBF | TSSOP | 16 | I | $4.26 | View | |
| LT3845MPFE | TSSOP | 16 | MP | $15.22 | $10.65 | View |
| LT3845MPFE#PBF | TSSOP | 16 | MP | $15.22 | $10.65 | View |
| LT3845MPFE#TR | TSSOP | 16 | MP | $10.71 | View | |
| LT3845MPFE#TRPBF | TSSOP | 16 | MP | $10.71 | View | |
| 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.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1073A | LT3845EFE Demo Board | 20V < Vin < 55V, Vout: 12V/ | $150.00 | |
| Buy Now | |||
Applications
- 12V and 42V Automotive and Heavy Equipment
- 48V Telecom Power Supplies
- Avionics and Industrial Control Systems
- Distributed Power Converters
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Simulate
LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. To download LTspice IV and other FREE simulation tools, please visit our Design Simulation page.
Related models available in LTspice IV
LT3845
LT3845A
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.