Linear MOSFET driver operates over extended temp range

Milpitas, Calif. — Linear Technology Corp. has introduced the H-grade version of the LTC4444/-5, a high-speed, high-input supply voltage (100-V), synchronous MOSFET gate driver designed to drive upper and lower power N-channel MOSFETs in synchronous rectified converter topologies. The LTC4444H/-5 operates over a junction temperature range of -40°C to 150°C, compared to the I-grade version’s -40°C to 125°C operating temperature range.


This driver, combined with power MOSFETs and one of Linear Technology’s DC/DC controllers, forms a complete high efficiency synchronous regulator.

Adaptive shoot-through protection is integrated to minimize dead time while preventing both the upper and lower MOSFETs from conducting simultaneously, said Linear. These drivers can source up to 1.4 A with a 1.5-Ohm pull-down impedance for driving the top MOSFET and a source current of 1.75 A with a 0.75-Ohm pull-down impedance for the bottom MOSFET, making it well-suited for driving high gate capacitance, high current MOSFETs.

The LTC4444H/-5 can drive multiple MOSFETs in parallel for higher current applications. Switching losses are minimized by the fast 8-ns rise, 5-ns fall time of the top MOSFET and 6-ns rise, 3-ns fall time of the bottom MOSFET when driving a 1,000-pF load, said Linear.

The LTC4444H/-5 is configured for two supply independent inputs. The high-side input logic signal is internally level-shifted to the bootstrap supply, which can function at up to 114V above ground. The LTC4444-5 drives both upper and lower MOSFET gates over a range of 4.5V to 13.5V and the LTC4444 drives both upper and lower MOSFET gates over a range of 7.2V to 13V.

Both parts are available in a thermally enhanced MSOP-8 package.

Pricing: Starts at $2.00 each in quantities of 1,000.