Tl494 Tl494c Sop-16 Pwm Controller

The TL494 IC is a fixed frequency current-mode PWM controller IC with all the functions that are required in the construction of the pulse-width modulation (PWM) control circuit on a single chip. The TL494 device incorporates all the functions required in the construction of a pulse-widthmodulation (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 singleended 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.

TL494 Specifications & Features

• Supply Voltage: 7V to 40V
• Number of Outputs: 2 Output
• Switching Frequency: 300 kHz
• Duty Cycle – Max: 45 %
• Output Voltage: 40 V
• Output Current: 200 mA
• Fall Time: 40 ns
• Rise Time: 100 ns
• Available in 16-pin PDIP, TSSOP, SOIC and SOP Packages

Note: Complete Technical Details can be found in the TL494 datasheet given at the end of this page. 

Equivalent/Substitute for TL494: UC3843, TL3842

Alternatives PWM controller IC:  UC2842, SG2524

Where to use the TL494 PWM Controller IC

The TL494 fixed frequency PWM Controller can be used for DC to DC conversion regardless of buck or boost topology. TL494 can be used to provide a constant current by varying the output voltage to the load. This IC feature an output control circuit, a flip flop, a dead time comparator, two different error amplifiers, a 5V reference voltage, an oscillator, and a PWM comparator.

So if you are looking for an IC to produce PWM signals for controlling a power switch based on the current flowing through the circuit, then this IC might be the right choice for you.

How to use TL494 IC

A test circuit from the TL494 datasheet is shown below.

Non inverting pins are connected to the Ref pin while inverting pins are connected to the ground. Test inputs are given to DTC and FEEDBACK pins. External capacitor and resistor are connected to pin 5 & 6 to control the oscillator frequency. The error amplifier compares a sample of the 5-V output to the reference and adjusts the PWM to maintain a constant output current

Applications of TL494

• Desktop PCs
• Microwave Ovens
• Server PSUs
• Solar Micro-Inverters
• Washing Machines: Low-End and High-End
• E-Bikes
• Power: Telecom/Server AC/DC Supplies:
• Smoke Detectors
• Solar Power Inverters

2D-Model of TL494

Dimensions for TL3494 IC is given below. These dimensions are for the PDSO package. If you are using a different package IC, please refer to the TL494 datasheet.