Hojas De Datos Tl494

TL494 PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074D – JANUARY 1983 – REVISED MAY 2002

D D D D D D D

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 Providesa Stable 5-V Reference Supply With 5% Tolerance Circuit Architecture Allows Easy Synchronization

D, DB, N, NS, OR PW PACKAGE (TOP VIEW)

1IN+ 1IN– FEEDBACK DTC CT RT GND C1

1 2 3 4 5 6 7 8

16 15 14 13 12 11 10 9

2IN+ 2IN– REF OUTPUT CTRL VCC C2 E2 E1

description
The TL494 incorporates all the functions required in the construction of a pulse-width-modulation (PWM) controlcircuit 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 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 erroramplifiers 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 provideeither common-emitter or emitter-follower output capability. The TL494 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 is characterized for operation from 0°C to 70°C. The TL494I is characterizedfor operation from –40°C to 85°C.
AVAILABLE OPTIONS PACKAGED DEVICES TA SMALL OUTLINE (D) TL494CD TL494ID PLASTIC DIP (N) TL494CN TL494IN SMALL OUTLINE (NS) TL494CNS — SHRINK SMALL OUTLINE (DB) TL494CDB — THIN SHRINK SMALL OUTLINE (PW) TL494CPW —

0°C to 70°C –40°C to 85°C

The D, DB, NS, and PW packages are available taped and reeled. Add the suffix R to device type (e.g., TL494CDR).

Pleasebe aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright  2002, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of TexasInstruments standard warranty. Production processing does not necessarily include testing of all parameters.

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

1

TL494 PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074D – JANUARY 1983 – REVISED MAY 2002

FUNCTION TABLE INPUT TO OUTPUT CTRL VI = GND VI = Vref OUTPUT FUNCTION Single-ended or parallel output Normal push-pull operation

functionalblock diagram
OUTPUT CTRL (see Function Table) RT 6 CT 5 ≈ 0.1 V 13 Oscillator 1D Dead-Time Control Comparator C1 Q2 11 10 Pulse-Steering Flip-Flop 12 Reference Regulator 14 VCC REF 4 Q1 8 9 C1 E1

DTC

Error Amplifier 1 1IN+ 1IN– 1 2 + – Error Amplifier 2 2IN+ 16 + – 2IN– 15

PWM Comparator

C2 E2

7 FEEDBACK 3 0.7 mA

GND

2

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265TL494 PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074D – JANUARY 1983 – REVISED MAY 2002

absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 V Amplifier input voltage, VI . . . . . . . . . . . . . ....