UC3525A is a monolithic integrated circuit that Included all of the control circuit necessary for a pulse width modulating regulator. There are a voltage reference, an error amplifier, a pulse width modulator, an oscillator, under-voltage lockout, soft start circuit, and output drivers in the chip. UC2527A -25 85 UC3525A, UC3527A 0 70 Oscillator frequency range Oscillator timing resistor Oscillator timing capacitorm Dead time resistor range Operating ambient temperature range (1) 2 UNIT V mA °C Range over which the device is functional and parameter limits are assured.