DocumentationDatasheet
Design Note
Reliability Data
LT Journal
Press Release
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Features
- High Speed Gate Driver for Forward Converter
- On-Chip Rectifier and Self-Starting Architecture Eliminates Need for Separate Gate Drive Bias Supply
- Wide Input Voltage Supply Range: 9V and Up
- Linear Regulator Controller for Fast Start-Up
- Precision UVLO with Adjustable Hysteresis
- Overcurrent Protection
- Volt-Second Limit Prevents Transformer Core Saturation
- Voltage Feedforward for Fast Transient Response
- Available in 10-Lead MSOP Package
Typical Application
Description
The LTC3725 is a controller for a single-switch forward converter and includes an on-chip gate driver.
For secondary-side control, combine the LTC3725 with the LTC3706 PolyPhase secondary-side synchronous forward controller to create a complete forward converter using a minimum of discrete parts. A proprietary scheme is used to multiplex gate drive signals across the isolation barrier through a tiny pulse transformer. The on-chip rectifier and the same pulse transformer provide gate drive bias power.
Alternatively, the LTC3725 can be used as a standalone voltage mode controller in a primary-side control architecture with optoisolator feedback. Voltage feedforward provides excellent line regulation and transient response.
MS-10E
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3725EMSE#PBF | MSOP | 10 | E | $3.66 | $2.56 |
| LTC3725EMSE#TRPBF | MSOP | 10 | E | $2.62 | |
| LTC3725IMSE#PBF | MSOP | 10 | I | $4.04 | $2.83 |
| LTC3725IMSE#TRPBF | MSOP | 10 | I | $2.89 | |
| LTC3725EMSE | MSOP | 10 | E | $7.32 | $5.12 |
| LTC3725EMSE#TR | MSOP | 10 | E | $5.24 | |
| LTC3725IMSE | MSOP | 10 | I | $8.08 | $5.66 |
| LTC3725IMSE#TR | MSOP | 10 | I | $5.78 |
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 |
|---|---|---|---|
| DC1031A-A | LTC3725EMSE/LTC3726EGN Demo Board | Single-Switch Forward Converter, 36V ≤ VIN ≤ 72V, Vout = 2.5V @ 20A | $250.00 | |
| DC1031A-B | LTC3725EMSE/LTC3726EGN Demo Board | Single-Switch Forward Converter, 36V ≤ VIN ≤ 72V, Vout = 3.3V @ 20A | $250.00 | |
| DC1031A-C | LTC3725EMSE/LTC3726EGN Demo Board | Single-Switch Forward Converter, 36V ≤ VIN ≤ 72V, Vout = 5V @ 20A | $250.00 | |
| DC1032A | LTC3725EMSE/LTC3726EGN 1/8 Brick | 36V < Vin < 72V, Vout: 12V/10A | $250.00 | |
| DC1174A-A | LTC3725EMSE/LTC3726EGN 1/8 Brick | 9V < Vin < 36V, Vout: 5.0V/10A | $200.00 | |
| DC1174A-B | LTC3725EMSE/LTC3726EGN 1/8 Brick | 9V < Vin < 36V, Vout: 12V/4A | $200.00 | |
| DC1174A-C | LTC3725EMSE/LTC3726EGN 1/8 Brick | 9V < Vin < 36V, Vout: 15V/3A | $200.00 | |
| DC1300A-A | LTC3725EMSE/LTC3726EGN 1/4 Brick | 9V < Vin < 36V, Vout: 5.0V/20A | $200.00 | |
| DC1300A-B | LTC3725EMSE/LTC3726EGN 1/4 Brick | 9V < Vin < 36V, Vout: 12V/8.4A | $200.00 | |
| DC1300A-C | LTC3725EMSE/LTC3726EGN 1/4 Brick | 9V < Vin < 36V, Vout: 15V/6.7A | $200.00 | |
| DC888A-A | LTC3725EMSE/LTC3706EGN Demo Board | 1/4 Brick, 36V ≤ Vin ≤ 72V, Vout: 3.3V/50A | Contact Factory | |
| DC888A-B | LTC3725EMSE/LTC3706EGN Demo Board | 1/4 Brick, 36V ≤ Vin ≤ 72V, Vout: 5V/40A | Contact Factory | |
| DC888A-C | LTC3725EMSE/LTC3706EGN Demo Board | 1/4 Brick, 36V ≤ Vin ≤ 72V, Vout: 12V/20A | Contact Factory |