Highest Integration, Self-Oscillating, Push-Pull FET Drivers for Current-Fed, Isolated Power Supplies
SUNNYVALE, CA-June 6, 2005-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX5075/MAX5077 push-pull FET drivers. Both devices integrate an oscillator with a programmable clock output for synchronization of an external PWM controller. An external resistor programs the oscillator frequency from 50kHz to 1.5MHz. The MAX5075 is available in versions with either a 1x, 2x, or 4x clock-output-to-MOSFET-driver frequency ratio. The MAX5077's clock-output-to-MOSFET-driver frequency ratio, however, can be set to 1x, 2x, or 4x by using two logic-level pins. These drivers are the essential building block for the design of high-efficiency, two-stage, current-fed isolated power supplies used in telecom and networking line cards.
The MAX5075/MAX5077 drive two MOSFETs connected to a center-tapped transformer primary, providing secondary-side isolated positive or negative voltages. The internal MOSFET drivers generate complementary signals to drive external ground-referenced n-channel MOSFETs with 3A peak gate-drive current and 50% duty cycle. Both devices operate from an input supply voltage range of 4.5V to 15V for use in designs where only 5V or 12V bias voltage is available.
The MAX5075/MAX5077 are rated for operation over the -40°C to +125°C automotive temperature range, and are available in 8-pin thermally enhanced µMAX and 14-pin exposed-pad TSSOP packages, respectively. Prices start at $0.93 for the MAX5075, and $1.05 for the MAX5077 (1000-up, FOB USA).
|
