LTC3775 - High Frequency Synchronous Step-Down Voltage Mode DC/DC Controller
Features
- Wide VIN Range: 4.5V to 38V
- Line Feedforward Compensation
- Low Minimum On-Time: tON(MIN) < 30ns
- Powerful Onboard MOSFET Drivers
- Leading Edge Modulation Voltage Mode Control
- ±0.75%, 0.6V Reference Voltage Accuracy Over Temperature
- VOUT Range: 0.6V to 0.8VIN
- Programmable, Cycle-by-Cycle Peak Current Limit
- Sense Resistor or RDS(ON) Current Sensing
- Programmable Soft-Start
- Synchronizable Fixed Frequency from 250kHz to 1MHz
- Selectable Pulse-Skipping or Forced Continuous Modes of Operation
- Low Shutdown Current: 14μA Typical
- Thermally Enhanced 16-Lead MSOP and 3mm × 3mm QFN Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3775 is a high efficiency synchronous step-down switching DC/DC controller that drives an all N-channel power MOSFET stage from a 4.5V to 38V input supply voltage. A patented line feedforward compensation circuit and a high bandwidth error amplifier provide very fast line and load transient response.
High step-down ratios are made possible by a low 30ns minimum on-time, allowing extremely low duty cycles. MOSFET RDS(ON) current sensing maximizes efficiency. Alternatively, a sense resistor can be used for higher current limit accuracy. Continuous monitoring of the voltages across the top and bottom MOSFETs allows cycle-by-cycle control of the inductor current, configurable by external resistors.
The soft-start function controls the duty cycle during start-up, providing a smooth output voltage ramp up. The operating frequency is user programmable from 250kHz to 1MHz and can be synchronized to an external clock.
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 |
|---|---|---|---|---|---|
| LTC3775EMSE#PBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LTC3775EMSE#TRPBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LTC3775EUD#PBF | 3x3 QFN-16 | UD | E | 05-08-1691 | Yes |
| LTC3775EUD#TRPBF | 3x3 QFN-16 | UD | E | 05-08-1691 | Yes |
| LTC3775IMSE#PBF | MS-16E | MSE | I | 05-08-1667 | Yes |
| LTC3775IMSE#TRPBF | MS-16E | MSE | I | 05-08-1667 | Yes |
| LTC3775IUD#PBF | 3x3 QFN-16 | UD | I | 05-08-1691 | Yes |
| LTC3775IUD#TRPBF | 3x3 QFN-16 | UD | I | 05-08-1691 | 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 | |
|---|---|---|---|---|---|---|
| LTC3775EMSE#PBF | MS-16E | E | $2.56 | $1.79 | Yes | |
| LTC3775EMSE#TRPBF | MS-16E | E | $1.85 | Yes | ||
| LTC3775EUD#PBF | 3x3 QFN-16 | E | $2.56 | $1.79 | Yes | |
| LTC3775EUD#TRPBF | 3x3 QFN-16 | E | $1.85 | Yes | ||
| LTC3775IMSE#PBF | MS-16E | I | $2.99 | $2.09 | Yes | |
| LTC3775IMSE#TRPBF | MS-16E | I | $2.15 | Yes | ||
| LTC3775IUD#PBF | 3x3 QFN-16 | I | $2.99 | $2.09 | Yes | |
| LTC3775IUD#TRPBF | 3x3 QFN-16 | I | $2.15 | 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.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1290A-A | LTC3775EUD Demo Board | 5V ≤ VIN ≤ 26V, VOUT = 1.2V @ 15A | $100.00 | |
| DC1290A-B | LTC3775EUD Demo Board | 5V ≤ VIN ≤ 36V, VOUT = 1.2V @ 10A | $100.00 | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3775IMSE#PBF | MS-16E | I | $2.99 | $2.09 | Yes | |
| LTC3775IMSE#TRPBF | MS-16E | I | $2.15 | Yes | ||
| LTC3775IUD#PBF | 3x3 QFN-16 | I | $2.99 | $2.09 | Yes | |
| LTC3775IUD#TRPBF | 3x3 QFN-16 | I | $2.15 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Automotive Systems
- Telecom and Industrial Power Supplies
- Point of Load Applications
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Design Tools
LTspice
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LTC3775
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.
