CS-3865

The CS-3865 is a high performance, fixed frequency, dual current mode controller. It is specifically designed for Off-Line and DC to DC converter applications offering the designer a cost effective solution with minimal external components. This integrated circuit features a unique oscillator for precise duty cycle limit and frequency control, a temperature compensated reference, two high gain error amplifiers, two current sensing comparators, drive output 2 enable pin, and two high current totem pole outputs ideally suited for driving power MOSFETs. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle-by-cycle current limiting, and a latch for single pulse metering of each output.

The absolute maximum ratings of CS3865 are (1)unique oscillator for precise duty cycle limit and frequency control; (2)current mode operation to 500 kHz; (3)automatic feed forward compensation; (4)separate latching PWMs for cycle-by-cycle current limiting; (5)internatlly trimmed reference with undervoltageg lockout; (6)drive output 2 enable pin; (7)two high current totem pole outputs; (8)input undervoltage lockout with hysteresis; (9)low start-up and operating current.

The absolute maximum ratings of CS3865 are (1)total power supply and zener current (Icc+Iz): 50 mA; (2)output current, source or sink (Note 1) lc: 10 A; (3)output energy (capacitive load per cycle): 50 J; (4)current sense, enable and voltage Vin: -03 to +55V; (5)feedback inputs Sync input -high state (voltage) VIH: 55V, low state (reverse current) IIL: -50 mA; (6)error amp output sink current Io: 10 mA.