TL494 Pulse width modulation pwm smps controller

TL494 pulse width modulation pwm smps controller is a very famous IC which is very commonly used as atx pc power supply smps controller. Their use is not limited to atx power supplies but they are also used in inverters and dc to dc converter. This device has all the necessary circuitry built on a chip which provides a very flexible and reliable switching regulator performance. TL494 chip or ic has two error amplifiers in it. There is an adjustable frequency oscillator on the chip. There is dead time control DCT which is a comparator. There is pulse steering control flip flop. There is internal 5V reference regulator and output control circuit used to interface with the outside world.

TL494 pulse width modulation smps controller

TL494 has two error amplifiers which works on common mode voltage whose range from -0.31V to Vcc-2.1V. Dead time control provides a 5% dead time and the dead time control comparator dtc has fix offset. The chip internal oscillation can be used or can be bypassed. It can be bypasses by terminating RT to reference output. This pin can be provided saw tooth input to CT. It can command common circuit in synchronous multiple rail power supply fashion.

TL494 chip or ic has two transistors output. These two transistors can be connected as common emitter or in the other way it can be configured as emitter follower. TL494 output can be selected as push pull or single ended. Both operations can be selected by output control function. The architecture of the chip is so good that it don’t allow mistake in the output.

TL494 IC images

There are two variants of TL494 available most commonly. The TL494C chip has operation temperature of 0 degree Celsius to 70 degree Celsius. Whereas TL494I chip can operates on extreme temperature of -40 degree Celsius to 85 degree Celsius.

TL494 chip have following features

1.       This chip internal circuit prohibits the double             pulse at the same time at either output

2.       TL494 output can be selected as single ended           or push pull

3.       TL494 chip is a complete switching regulator and consist all necessary circuits for power supply.

TL494 outputs high current pulse of 201mA as source or sink.