PWM Control Circuit - TL494

TL494 (ACTIVE)

PWM Control Circuit

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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

View more

Parametrics Compare all products in PWM and Resonant Controller

 
Topology
Control Method
Vin (Min) (V)
Vin (Max) (V)
Frequency (Max) (kHz)
UVLO Thresholds On/Off (V)
Duty Cycle (Max) (%)
Special Features
Rating
Operating Temperature Range (C)
Pin/Package
Approx. Price (US$)
TL494 TL594
Boost
Buck
Flyback
Forward
Full-Bridge
Half-Bridge
Push-Pull    
Boost
Buck
Flyback
Forward
Full-Bridge
Half-Bridge
Push-Pull    
Voltage     Voltage    
7     7    
40     40    
300     300    
  6.1/6    
45     45    
Adjustable Switching Frequency
Error Amplifier    
Adjustable Switching Frequency
Error Amplifier    
Catalog     Catalog    
-40 to 85
0 to 70    
-40 to 85
0 to 70    
16PDIP
16SO
16SOIC
16TSSOP    
16PDIP
16SO
16SOIC
16TSSOP    
0.17 | 1ku     0.27 | 1ku    
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