LT3751 controller charges capacitors to 1000V

Linear Technology's LT3751 is a flyback controller that rapidly charges 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 one second, making it ideal for applications such as professional photoflash systems, RF security, inventory-control systems and specialised high-voltage power supplies.

The LT3751 can be configured for primary-side output voltage sensing without needing an optocoupler.

For lower noise and tighter regulation applications, a resistor divider network from output voltage can be used to regulate the output, making it suited for high-voltage power-supply requirements.

Boundary mode control minimises transition losses and delivers up to 88 per cent efficiency.

The VCC input voltage ranges from 5 to 24V, enabling it to operate from a variety of power sources.

The VTRANS supply-voltage range is dependent upon the choice of external components with the LT3751's internal shunt regulator.

A low 106mV differential current sense threshold accurately limits peak-switch current.

Additional features include: an on-board selectable 5.6 or 10.5V powerful 2A N-channel Mosfet gate driver, a Charge pin that lets the user initiate a new charge cycle and remote shutdown, and undervoltage and overvoltage lockout on the VTRANS and VCC input voltages.

The Done pin indicates when the capacitor has reached its programmed voltage and has stopped charging.

The LT3751 comes in a thermally enhanced 4 x 5mm QFN-20 package and is offered in extended and industrial temperature ranges from -40C to 125C.

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