UC3525A

www.fairchildsemi.com UC3525A SMPS Controller Features 5V ± 1% Reference Oscillator Sync terminal Internal Soft Start Deadtime Control Under-Voltage Lockout Description 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. 16-DIP 1 Internal Block Diagram Rev. 5.0 ©2000 Fairchild Semiconductor International UC3525A Absolute Maximum Ratings Parameter Supply Voltage Collector Supply Voltage Output Current, Sink or Source Reference Output Current Oscillator Charging Current Power Dissipation (TA = 25°C) Operating Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) Symbol VCC VC IO IREF ICHG(OSC) PD TOPR TSTG TLEAD Value 40 40 500 50 5 1000 0 ~ +70 -65 ~ +150 +300 Unit V V mA mA mA m/W °C °C °C Electrical Characteristics (VCC = 20V, TA = -30°C to + 85°C, unless otherwise specified) Parameter REFERENCE SECTION Reference Output Voltage Line Regulation Load Regulation Short Circuit Output Current Total Output Variation (Note 1) Temperature Stability (Note 1) Long Term Stability (Note 1) OSCILLATOR SECTION Initial Accuracy (Note 1, 2) Frequency Change With Voltage Maximum Frequency Minimum Frequency Clock Amplitude (Note 1, 2) Clock Width (Note 1, 2) Sync Threshold Sync Input Current ACCUR ∆f/∆VCC f(MAX) f(...