TL494

www.fairchildsemi.com TL494 SMPS Controller Features Internal regulator provides a stable 5V reference supply trimmed to 5% Uncommitted output TR for 200mA sink or source current Output control for push-pull or single-ended operation Variable duty cycle by dead time control (pin 4) Complete PWM control circuit On-chip oscillator with master or slave operation Internal circuit prohibits double pulse at either output Description The TL494 is used for the control circuit of the PWM switching regulator. The TL494 consists of 5V reference voltage circuit, two error amplifiers, flip flop, an output control circuit, a PWM comparator, a dead time comparator and an oscillator. This device can be operated in the switching frequency of 1 KHz to 300 KHz. 16-DIP 1 16-SOP 1 Internal Block Diagram Rev. 5.0 ©2000 Fairchild Semiconductor International TL494 Absolute Maximum Ratings Parameter Supply Voltage Collector Supply Voltage Output Current Amplifier Input Voltage Power Dissipation (TA = 25°C) Operating Temperature Range Storage Temperature Range Symbol VCC VC IO VIN PD TOPR TSTG Value 42 42 250 VCC + 0.3 1 (TL494CN) 0.9 (TL494CD) 0 ~ +70 -65 ~ + 150 Unit V V mA V W °C °C 2 TL494 Electrical Characteristics (VCC = 20V, f = 10KHz, TA = 0°C to + 70°C, unless otherwise specified) Parameter REFERENCE SECTION Reference Output Voltage Line Regulation Temperature Coefficient of VREF Load Regulation Short-Circuit Output Currnet OSCILLATOR SECTION Oscillation Frequency Fre...