Active Clamp Synchronous Forward Controller
Features and Benefits
- Input Voltage Range: LT3752: 6.5V to 100V, LT3752-1:Limited Only by External Components
- Internal Housekeeping DC/DC Controller
- Programmable Volt-Second Clamp
- High Efficiency Control: Active Clamp, Synchronous Rectification, Programmable Delays
- Short-Circuit (Hiccup Mode) Overcurrent Protection
- Programmable Soft-Start/Stop
- Programmable OVLO and UVLO with Hysteresis
- Programmable Frequency (100kHz to 500kHz)
- Synchronizable to an External Clock
The LT3752/LT3752-1 are current mode PWM controllers optimized for an active clamp forward converter topology. A DC/DC housekeeping controller is included for improved efficiency and performance. The LT3752 allows operation up to 100V input and the LT3752-1 is optimized for applications with input voltages greater than 100V.
A programmable volt-second clamp allows primary switch duty cycles above 50% for high switch, transformer and rectifier utilization. Active clamp control reduces switch voltage stress and increases efficiency. A synchronous output is available for controlling secondary side synchronous rectification.
The LT3752/LT3752-1 are available in a 38-lead plastic TSSOP package with missing pins for high voltage spacings.
- Offline and HV Car Battery Isolated Power Supplies
- 48V Telecommunication Isolated Power Supplies
- Industrial, Automotive and Military Systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (3)
Demonstration circuit 2175A is an active clamp forward converter with synchronous rectification featuring the LT3752/LT8311 chipset.
This circuit was designed to demonstrate the high levels of performance, efficiency and high power. It operates at 200kHz and produces a regulated 12V, 13A output from a wide input voltage range of 9V to 36V, making it well suited for telecom, industrial, and other applications. Synchronous rectification helps to attain efficiency exceeding 93%.
Demonstration circuit 1929A is a 200W active clamp forward converter featuring the LT3752-1/LT8311 chipset. The LT8311 is a secondary-side synchronous rectifier controller. The solution operates at about 100kHz and produces an isolated, regulated 12V / 16.7A output from an input voltage ranging from 150V to 400V, making it well suited for automotive, industrial, and other applications.
Demonstration circuit 1994A is an active clamp forward converter with synchronous rectification featuring the LT3752/LT8311 chipset. This circuit was designed to demonstrate the high levels of performance, efficiency, and small solution size attainable using these parts. It operates at 240kHz and produces a regulated 12V, 12A output from an input voltage range of 18 to 72V: suitable for telecom, industrial, and other applications. It has an eighth-brick footprint area. Synchronous rectification helps to attain efficiency exceeding 94%.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
LT3752 Companion Parts
Recommended Related Parts
Solutions Bulletins & Brochures (1)
Press Release (1)
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.