TL494 Pulse-Width-Modulation Control Circuits

1 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

2 Applications

• Desktop PCs

• Microwave Ovens

• Power Supplies: AC/DC, Isolated, With or Without

PFC

• Server PSUs

• Solar Micro-Inverters

• Washing Machines: Low-End and High-End

• E-Bikes

• Power: Telecom/Server AC/DC Supplies:

Dual Controller: Analog

• Smoke Detectors

• Solar Power Inverters

3 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 TL494 device is characterized for operation from

0°C to 70°C. The TL494I device is characterized for

operation from –40°C to 85°C.

Device Information(1)

PART NUMBER

PACKAGE (PIN)

BODY SIZE

TL494

SOIC (16)

9.90 mm × 3.91 mm

PDIP (16)

19.30 mm × 6.35 mm

SOP (16)

10.30 mm × 5.30 mm

TSSOP (16)

5.00 mm × 4.40 mm

(1)

For all available packages, see the orderable addendum at

the end of the data sheet.

4 Simplified Block Diagram

13

12

11

10

14

15

16

4

5

6

7

3

2

1

+

9

8

VREF

Osc

Control

TL494

TL494

SLVS074I – JANUARY 1983 – REVISED JULY 2022

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.