TI Unveils UCC28220/UCC28221 PWM Controllers
Texas Instruments Inc. (TI, Dallas, TX) announced what is claimed to be the industry’s first single-chip, interleaved, pulse-width modulation (PWM) controllers for 50A to 100A high-current power supplies in off-line and dc/dc converters used in computer servers, telecom, datacomm and consumer systems.
The UCC28220 and UCC28221 peak current-mode controllers use advanced interleaving techniques to control two isolated power stages to maximize power density, reduce output-current ripple and improve transient response. The devices, available in either interleaved forward or interleaved fly-back isolated topologies, integrate two PWM channels operating at 180° out-of-phase to control one high-current output. In addition, the controllers provide programmable internal-slope compensation with an internal circuit to precisely match currents between the two channels.
The UCC28220 and UCC28221 PWM controllers provide an accurate maximum duty clamp, which can be programmed between 60% to 90% duty cycles per channel. The controllers also include programmable soft-start and highly accurate input line under-voltage and over-voltage thresholds with programmable hysteresis for each threshold. Additionally, the UCC28221 has a 110V startup device that removes the need for an external trickle charge boot strap resistor.
The UCC28220 and UCC28221 are now available in volume. The UCC28220 is available in both 16-pin SOIC packages and low-profile TSSOP packages. The UCC28221 with the high-voltage startup circuit comes in a 16-pin SOIC and a slightly larger 20-pin TSSOP package. Pricing is $1.49 and $1.57 in quantities of 1,000 units for the UCC28220 and UCC28221, respectively.
