Linear Tech Adds 100V Synchronous N-Channel 3A MOSFET Drivers For DC-DC Converters
Linear Technology Corp. announced the LTC4444, a high-speed, high input supply voltage (100V) synchronous MOSFET driver designed to drive upper and lower power N-Channel MOSFETs in synchronous rectified converter topologies. This driver, combined with power MOSFETs and one of Linear Technology’s many dc-dc controllers, are said to form a complete high efficiency synchronous converter.
The driver can source up to 2.5A with a 1.2Ω pull-down impedance for driving the top MOSFET and source 3A with a 0.55Ω pull-down impedance for the bottom MOSFET, making it suitable for driving high gate capacitance, high current MOSFETs. The LTC4444 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 1,000 pF load minimize switching losses. Adaptive shoot-through protection is integrated to minimize dead time while preventing both the upper and lower MOSFETs from conducting simultaneously.
The LTC4444 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 7.2 to 13.5V.
The LTC4444EMS8 and LTC4444IMS8 are offered in a thermally enhanced MSOP-8 package with prices starting at $1.69 for 1000-piece quantities.
