Date: 08/12/2008

Flyback controller to rapidly charge large capacitors of any size

Linear Technology launched the LT3751, a flyback controller designed to rapidly charge large capacitors to voltages as high as 1000V. The LT3751 drives an external N-Channel MOSFET and can charge a 1000uF capacitor to 500V in less than 1 second, making it ideal for applications such as professional photoflash systems, RF security, inventory control systems and specialized high voltage power supplies.

Some of the key features are discussed below:

1. For lower noise and tighter regulation applications, a resistor divider network from output voltage can be used to regulate the output
2. Boundary mode control minimizes transition losses and delivers up to 88% efficiency.
3. VCC input voltage ranges from 5V to 24V, enabling it to operate from a variety of power sources
4. VTRANS supply voltage range is dependent upon the choice of external components with the LT3751's internal shunt regulator
5. A low 106mV differential current sense threshold accurately limits peak switch current.
6. Easily Adjustable Output Voltage
7. Configurable for Primary Side Voltage Sense (without needing an optocoupler)
8. Selectable 5.6V or 10.5V Internal Gate Driver
9. Integrate 2A Gate Driver with Rail-to-Rail Operation
10. Current Mode Control
11. Programmable Input Over/Undervoltage Lockout
12. Operating temperature ranges from -40°C to 125°C
13. Remote shutdown
14. The DONE pin indicates when the capacitor has reached its programmed voltage and has stopped charging.

Packaging: packaged in a thermally enhanced QFN-20 package,
Size: 4mm x 5mm
Price: the 1000-piece price starts at $3.65 each.

For further information visit: www.linear.com