UC3860

The UC3860 family of control ICs is a versatile system for resonant mode power supply control. This device easily implements frequency modulated fixed-on-time control schemes as well as a number of other power supply control schemes with its various dedicated and programmable features.

The UC3860 includes a precision voltage reference, a wide-bandwidth error amplifier, a variable frequency oscillator operable to beyond 3MHz, an oscillator-triggered one-shot, dual high-current totem-pole output drivers,and a programmable toggle flip-flop. The output mode is easily programmed for various sequences such as A, off, B, off; A & B, off; or A, B, off. The error amplifier contains precision output clamps that allow programming of minimum and maximum frequency.

The device UC3860 also contains an uncommitted comparator, a fast comparator for fault sensing, programmable soft start circuitry, and a programmable restart delay. Hic-up style response to faults is easily achieved. In addition,the UC1860 contains programmable under voltage lockout circuitry that forces the output stages low and minimizes supply current during start-up conditions.