DC/DC Controllers Feature Foldback Current Protection October 2003 Issue Published Date: October 13, 2003
Aimed at set-top boxes, graphic cards, and PC power supplies, the MAX8545, MAX8546, and MAX8548 voltage-mode, PWM step-down dc/dc controllers feature digital soft-start, current-limit, and foldback short-circuit protection. The foldback current protection feature claims to reduce current limiting by 80%, minimize power dissipation under short-circuit conditions, and latch off the devices when an output short is detected. Each device employs gate drivers rated at 2.5 ohms, allowing for output currents from 1A to 15A, and provides output voltages down to 0.8V. Input voltage range is from 2.7V to 28V with no need for additional biasing. The MAX8545 and MAX8546 operate at a switching frequency of 300 kHz while the MAX8548 operates at 100 kHz. Available in 10-pin microMAX packages, prices start at $0.92 for the MAX8545/ MAX8546 and $0.88 for the MAX8548 each/1,000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.
