TI Introduces High-Speed, 4-A MOSFET Driver for Server and dc-dc Power Systems
Texas Instruments Inc. (TI) introduced a 4-A, high-speed, synchronous driver for N-channel complementary driven power MOSFETs. The 2-MHz driver simplifies power design in high-current single- and multi-phase applications, such as voltage regulator module (VRM) designs, notebook computers, isolated power supplies with secondary side synchronous rectifiers and dc-dc converters where improved efficiency is critical.
Achieving high efficiency and low electromagnetic interference (EMI) emissions, TI's TPS28225 driver controls MOSFET gates with 4.5 V to 8.8 V, with highest power efficiency between 7 V and 8 V. The TPS28225 features 14-ns adaptive dead-time control, 14-ns propagation delays and high-current 2-A source and 4-A sink drive capability.
"Power system designers continue to require higher operating efficiency and performance when using standard 5 V and 12 V drivers," said Larry Spaziani, product line manager of TI's power supply control business. "Several top power customers using the TPS28225 achieve a three- to eight-percent improvement in power efficiency, while increasing their switching frequency, decreasing their module size and significantly improving transient response."
The driver's 0.4 ohm impedance for the lower gate driver holds the gate of the power MOSFET below its threshold level to ensure no shoot-through current occurs during high dV/dT phase node transitions. A bootstrap capacitor charged by an internal diode allows the device to use N-channel MOSFETs in half-bridge configuration.
The TPS28225 features a three-state pulse-width modulation (PWM) input, which is compatible with all multi-phase controllers, such as TI's TPS40091, that employ a three-state output feature. The shutdown mode feature prevents a load from the reversed output voltage. The TPS28225 MOSFET driver is available today in volume from TI and its authorized distributors. The device is offered in an economical, 8-pin, SOIC and thermally enhanced 3-mm by 3-mm DFN, 8-pin package. Suggested retail pricing in 1,000-piece quantities is $0.60. Samples of the TPS28225, design application notes and TI's easy-to-use online power management selection tool are available.
