MOSFET driver provides 100% duty cycle capability
A high speed, high side N-channel MOSFET driver that operates up to a 150V supply voltage has been announced by Analog Devices, which recently acquired Linear Technology. The internal charge pump of the LTC7000/-1 fully enhances an external N-channel MOSFET switch, allowing it to remain on indefinitely. The LTC7000/-1’s powerful 1Ω gate driver can drive large gate capacitance MOSFETs with very short transition times, suitable for both high frequency switching and static switch applications.
The LTC7000/-1 operates over a 3.5-135V, 150VPK input supply range with a 3.5-15V bias voltage range. It detects an overcurrent condition by monitoring the voltage across an external sense resistor placed in series with the drain of the external MOSFET. When the LTC7000/-1 senses that the switch current has exceeded a preset level, a fault flag is asserted and the switch is turned off for a period of time set by an external timing capacitor. After a predetermined time period, the LTC7000/-1 automatically retries.
The LTC7000/-1 is designed to receive a ground referenced, low voltage digital input signal and quickly drive a high side N-channel power MOSFET whose drain can be as high as 150V above ground. The fast 13ns rise and fall times, when driving a 1,000pF load, minimise switching losses. The LTC7000 is the full featured device and has additional features over the LTC7000-1, including enable, overvoltage lockout, adjustable current limit and current monitoring.
The LTC7000 is available in the MSOP-16 package and the LTC7000-1 is available in the MSOP-16 (12) with four leads removed for high voltage spacing. Three operating junction temperature grades are available, with extended and industrial versions from -40 to 125°C, high temp automotive version from -40 to 150°C and a military grade from –55 to 150°C.