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.
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 |
Changes from Revision H (March 2017) to Revision I (July 2022)
Changes from Revision G (January 2015) to Revision H (March 2017)
Changes from Revision F (January 2014) to Revision G (January 2015)
PIN | TYPE | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
1IN+ | 1 | I | Noninverting input to error amplifier 1 |
1IN- | 2 | I | Inverting input to error amplifier 1 |
2IN+ | 16 | I | Noninverting input to error amplifier 2 |
2IN- | 15 | I | Inverting input to error amplifier 2 |
C1 | 8 | O | Collector terminal of BJT output 1 |
C2 | 11 | O | Collector terminal of BJT output 2 |
CT | 5 | — | Capacitor terminal used to set oscillator frequency |
DTC | 4 | I | Dead-time control comparator input |
E1 | 9 | O | Emitter terminal of BJT output 1 |
E2 | 10 | O | Emitter terminal of BJT output 2 |
FEEDBACK | 3 | I | Input pin for feedback |
GND | 7 | — | Ground |
OUTPUT CTRL | 13 | I | Selects single-ended/parallel output or push-pull operation |
REF | 14 | O | 5-V reference regulator output |
RT | 6 | — | Resistor terminal used to set oscillator frequency |
VCC | 12 | — | Positive Supply |