low-voltage synchronous buck controllers

Unitrode Corp. (Merrimack, NH) recently introduced a family of low-voltage synchronous buck controllers designed for on-board power and other dc/dc power conversion applications in the EDP, data communication and telecommunication markets. The UCC3585 features an industry-low input voltage (2.7V-6.0V) operation that is compatible with 3.3V-only, battery input and other low voltage systems, according to Unitrode. The device's 1.25V-4.5V output voltage operation is claimed by Unitrode to have better than 1 percent dc accuracy. Internal features of the UCC3585 include a tracking feature which allows the converter output to track the input voltage during power-up. The tracking feature is enhanced by a user configurable track-and-hold threshold that prevents overshoot of the output voltage during power-up. Another primary feature of the UCC3585 is its two internally-controlled gate drive outputs, one for directly driving a p-channel PWM switch and the other for an n-channel synchronous rectifier switch. These outputs are designed to prevent cross conduction and reduce external drive circuitry. Standard packaging options of the UCC3585 are DIL-16, SOIC-16 or SSOP-16. Pricing for the UCC3585 ranges from $1.93 to $2.01 each in quantities of 1,000 or more. Commercial temperature range samples in surface-mount and thru-hole are now available from stock.