Linear Technology has announced the LTC4446, a high frequency, high input supply voltage (100V) MOSFET driver designed to drive upper and lower N-Channel power MOSFETs in a 2-transistor forward converter. This driver, combined with power MOSFETs and one of Linear Technology's DC/DC controllers form a complete high efficiency 2-transistor forward converter or can be configured as a fast acting high voltage DC switch.
This powerful driver can source up to 2.5A with a 1.2 Ohm pull-down impedance for driving the top MOSFET and can source 3A with a 0.55 Ohm pull-down impedance for the synchronous MOSFET, making it ideal for driving high gate capacitance, high current MOSFETs. The LTC4446 can also drive multiple MOSFETs in parallel for higher current applications. The fast 8ns rise time, 5ns fall time of the top MOSFET, and 6ns rise time, 3ns fall time of the bottom MOSFET when driving a 1,000pF load minimize switching losses.
The LTC4446 is configured for two supply-independent inputs. The high-side input logic signal is internally level-shifted to the bootstrap supply, which may function at up to 114V above ground. Furthermore, this part drives both upper and lower MOSFET gates over a range of 7.2V to 13.5V.
The LTC4446EMS8 and LTC4446IMS8 are offered in a thermally enhanced MSOP-8 package with prices starting at $1.69 for 1000-piece quantities.
Summary of Features of the LTC4446:
* High Side/Low Side N-Channel MOSFET Driver
* 100V Maximum Supply Voltage
* Ideal for 2-Transistor Forward Converters
* High Voltage Switch Applications
* High Drive Current - 3A Source, 0.55Ohm Sink
* 7.2V to 13.5V Gate Drive Voltage
* Top Gate-8ns Rise, 5ns Fall Times when Driving 1,000pF
* Bottom Gate-6ns Rise, 3ns Fall Times when Driving 1,000pF
* Undervoltage Lockout for Gate Drive Voltage
* Thermally Enhanced MSOP-8 Package