描述 Description

The TL494 PWM Controller 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 PWM Controller 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. This PWM Controller 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 PWM Controller is characterized for operation from 0C to 70C. The TL494I is characterized for operation from -40C to 85C. The TL494B is characterized for operation from -40C to 125C. The NCV494B is characterized for -40C to 125C and certified for automotive applications.

特性 Features

? Variable Frequency Operation (up to 200 KHz)
? Optimize system size and efficiency
? PWM Buck Controller Configuration
? Simple to use in buck configuration
? Complete Pulse Width Modulation Control Circuitry
? On-Chip Oscillator with Master or Slave Operation
? On-Chip Error Amplifiers
? On-Chip 5.0 V Reference
? Adjustable Deadtime Control
? Uncommitted Output Transistors Rated to 500 mA Source or Sink
? Output Control for Push-Pull or Single-Ended Operation
? Undervoltage Lockout
? Pb-Free Packages are Available*

應(yīng)用 Application

? Off-line power supply
? Buck converter
? VPA (Vehicle Power Adapter)
? LED Lighting

簡(jiǎn)介

TL494屬于集成電路（IC）的PMIC-穩(wěn)壓器-DCDC開(kāi)關(guān)式控制器。由制造生產(chǎn)的TL494DC-DC 開(kāi)關(guān)控制器PMIC（電源管理集成電路）DC 到 DC 開(kāi)關(guān)式控制器是用于高效率電路的穩(wěn)壓 IC，其配置為生成高于（突升或步升）或低于（突降或步降）輸入電源的輸出電源電壓。其他拓?fù)浣Y(jié)構(gòu)可能包括：降壓-升壓、反激、正激、Cuk、SEPIC、全橋、半橋和推挽式。這些器件不同于需要最小電壓并“燒盡”多余電壓的線性穩(wěn)壓器。