2.5MHz, UNIVERSAL-INPUT, DUAL-OUTPUT PWM CONTROLLER HAS PRECISION-PROGRAMMABLE SWITCHING FREQUENCY AND START/STOP VOLTAGE
SUNNYVALE, CA-March 12, 2004-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX5069, a dual-output, high-frequency, current-mode PWM controller for isolated telecom DC-DC or universal, off-line input AC-DC power supplies. This device allows the design of half-bridge, full-bridge, and push-pull power supplies.
The device's switching frequency is programmable from 50kHz to 2.5MHz using an external-programming resistor. Moreover, the switching frequency is internally trimmed to ±4.5% accuracy, thus eliminating the need to oversize the magnetic components. The device's turn-on/turn-off voltages can be precisely programmed using external resistors. Integrated, digital softstart guarantees a monotonic rise on the power-supply output and eliminates overshoot during power up.
The MAX5069's programmable, integrating-fault-protection circuit provides robust fault protection. This feature prevents component overheating by turning off the power supply in the event of sustained overcurrent conditions or when there is a direct short circuit at the power-supply output. Furthermore, an internal error amplifier with a ±2% accurate reference enables isolated power supplies with primary- or secondary-side regulation to be designed. The device can be synchronized to an external clock, thus eliminating beat-frequency effects when running multiple power supplies in a system.
The MAX5069's 50µA startup current allows the use of a high-value startup resistor, thereby reducing power loss across the startup resistor in standby mode. The device's gate-driver output is capable of sourcing or sinking 1A. In addition, the current-sense threshold is 320mV. These several features allow the design of high-power and high-efficiency power supplies. The cycle-by-cycle current-limit propagation delay is 40ns, which allows fast turn-off of the power supply during output short-circuit conditions.
Rated for operation over a wide -40°C to +125°C temperature range, the MAX5069 is available in a thermally enhanced, 16-pin TSSOP package. Prices start at $1.48 (1000-up, FOB USA).
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