PWM Controller Boosts Power Supply Performance

Designed for isolated telecom dc/dc or universal offline input ac/dc power supplies, the MAX5094 is a high-performance single-ended current-mode PWM controller that is pin compatible with the industry standard and multisourced UCC28C43 and UCC28C45. According to the company, the MAX5094 provides lower startup current, tighter oscillator-frequency tolerance, and tighter current-sense accuracy, so designers can easily upgrade existing power-supply designs for higher performance with minimal component changes. Switching frequency of the device is externally programmable from 20kHz to 1MHz. In addition, the switching frequency is trimmed for ±7% accuracy while current-limit threshold and start/stop voltages are trimmed for ±5% accuracy. The timing-capacitor discharge current is trimmed to ±5%. This allows accurate programming of the maximum duty cycle, which is 100% and 50% for the MAX5094A and MAX5094B respectively. Other features include a cycle-by-cycle current-limit propagation delay of 60 ns, startup current of 35 µA, gate-driver output capable of sourcing 2A and sinking 1A, and an operating temperature range from -40°C to 125°C. Available in eight-pin SO and microMAX packages, pricing starts at $0.64 each/1,000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.