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 SynchronizationPinout
Specifications
|
|
|
MIN MAX |
UNIT |
| VCC |
Supply voltage(2) |
|
41 |
V |
| VI |
Amplifier input voltage |
|
VCC + 0.3 |
V |
| VO |
Collector output voltage |
|
41 |
V |
| IO |
Collector output current |
|
250 |
mA |
| JA Package thermal impedance(3)(4) |
D package |
73 |
/W |
| DB package |
82 |
| N package |
67 |
| NS package |
64 |
| PW package |
108 |
|
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds |
|
260 |
|
| Tstg |
Storage temperature range |
|
65 150 |
|
DescriptionThe TL494 is a fixed frequency, pulse width modulation control circuit designed primarily for SWITCHMODE power supply control.Features of the TL494 are:(1)complete pulse width modulation control circuitry;(2)on-chip oscillator with master or slave operation;(3)on-chip error amplifiers;(4)on-chip 5.0 V reference;(5)adjustable deadtime control;(6)uncommitted output transistors rated to 500 mA source or sink;(7)output control for push-pull or single-ended operation;(8)undervoltage lockout.
The absolute maximum ratings of the TL494 can be summarized as:(1)power supply voltage:42 V;(2)collector output voltage:42 V;(3)collector output current (each transistor):500 mA;(4)amplifier input voltage range:-0.3 to +42 V;(5)power dissipation @ TA</=45°C:1000 mW;(6)thermal resistance,junction-to-ambient:80°C/W;(7)operating junction temperature:125 °C;(8)storage temperature range:-55 to +125 °C;(9)operating ambient temperature range:0 to +70°C(TL494C) or -25 to +85°C(TL494I);(10)derating ambient temperature:45°C.If you want to know more information such as the electrical characteristics about the TL494,please download the datasheet in www.seekic.com or www.chinaicmart.com .
The TL494 incorporate on a single monolithic chip all the functions required in the construction of a pulse-width-modulation control,
The TL494 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 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 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 characterized for operation from 40°C to 85°C.
TL494 Data Sheet
