The XL494 device integrates all the functions required to build a pulse width modulation (PWM) control circuit on a single chip. The chip is mainly used for power supply control, and the power supply control circuit can be flexibly adjusted according to the specific application.
The XL494 device contains two error amplifiers, an on-chip adjustable oscillator, a dead time control (DTC) comparator, a pulse control trigger, and a 5V (5%) precision regulator and output control circuit.
The common mode voltage range of the error amplifier is -0.3V to Vcc-2V. The dead time control comparator has a fixed offset that provides approximately 5% dead time. The on-chip oscillator can be bypassed by terminating RT to the reference output and providing a sawtooth input to CT, or it can drive common circuits in synchronous multi-rail power supplies.
The unconnected output transistor provides common emitter or emitter follower output capability. The XL494 device provides push-pull or single-ended output operation, which can be selected by the output control function. The chip is structurally prohibited from the possibility of double pulse output during push-pull operation. XL494 operating temperature -40°C~85°C.
