原标题：TL494制作200W升压变换器电路图

　　电路很简单，元件也没什么特殊要求，容易做

　　TL494

　　PWM Controller

　　Description

　　The TL494 device incorporates all the functions required in the construction of a pulse-width-modulation (PWM) control circuit on a single chip. Designed primarily for power-supply control, this device offers the flexibility to tailor the power-supply control circuitry to a specific application.

　　The TL494 device contains two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC) comparator, a pulse-steering control flip-flop, a 5-V, 5%-precision regulator, and output-control circuits.

　　The error amplifiers exhibit a common-mode voltage range from –0.3 V to VCC – 2 V. 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 the common circuits in synchronous multiple-rail power supplies.

　　The uncommitted output transistors provide either common-emitter or emitter-follower output capability. The TL494 device provides for push-pull or single-ended output operation, which can be selected through the output-control function. The architecture of this device prohibits the possibility of either output being pulsed twice during push-pull operation.

　　The TL494C device is characterized for operation from 0°C to 70°C. The TL494I device is characterized for operation from –40°C to 85°C.

　　Features

　　Complete PWM Power-Control Circuitry

　　Uncommitted Outputs for 200-mA Sink or

　　Source Current

　　Output Control Selects Single-Ended or

　　Push-Pull Operation

　　Internal Circuitry Prohibits Double Pulse at

　　Either Output

　　Variable Dead Time Provides Control Over

　　Total Range

　　Internal Regulator Provides a Stable 5-V Reference Supply With 5% Tolerance

　　Circuit Architecture Allows Easy Synchronization