Overview
The TL494CDRG4, produced by Texas Instruments, is a pulse-width-modulation (PWM) control circuit integrated into a single chip. This device is primarily designed for power-supply control and offers the flexibility to tailor the power-supply control circuitry to specific applications. It includes two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC) comparator, a pulse-steering control flip-flop, and a 5-V, 5%-precision regulator. The TL494 is characterized for operation from 0°C to 70°C, making it suitable for a wide range of environments.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Voltage Range | 7 | - | 40 | V |
| Output Voltage (REF) | 4.75 | 5 | 5.25 | V |
| Output Regulation (IO = 1 mA to 10 mA) | 1 | - | 15 | mV |
| Output Voltage Change with Temperature | 2 | - | 10 | mV/V |
| Short-Circuit Output Current (REF = 0 V) | - | - | 25 | mA |
| Oscillator Frequency (CT = 0.01 μF, RT = 12 kΩ) | 10 | - | - | kHz |
| Operating Temperature Range | 0 | - | 70 | °C |
Key Features
- Two error amplifiers with a common-mode voltage range from –0.3 V to VCC – 2 V.
- An on-chip adjustable oscillator that can be bypassed or used to drive common circuits in synchronous multiple-rail power supplies.
- A dead-time control (DTC) comparator with a fixed offset providing approximately 5% dead time.
- A pulse-steering control flip-flop that alternately directs the modulated pulse to each of the two output transistors.
- Uncommitted output transistors providing either common-emitter or emitter-follower output capability.
- Push-pull or single-ended output operation selectable through the output-control function.
- A 5-V, 5%-precision regulator with internal programming for initial accuracy and stability.
Applications
The TL494 is designed primarily for power-supply control and can be used in various applications such as:
- Switch-mode power supplies.
- Synchronous multiple-rail power supplies.
- DC-DC converters.
- Motor control systems.
- Other power management and control circuits where PWM is required.
Q & A
- What is the primary function of the TL494?
The TL494 is a pulse-width-modulation (PWM) control circuit designed primarily for power-supply control. - What is the input voltage range of the TL494?
The input voltage range of the TL494 is from 7 V to 40 V. - What is the precision of the 5-V regulator in the TL494?
The 5-V regulator in the TL494 has a precision of 5%. - Can the oscillator in the TL494 be bypassed?
Yes, the oscillator in the TL494 can be bypassed by terminating RT to the reference output and providing a sawtooth input to CT. - What is the operating temperature range of the TL494?
The operating temperature range of the TL494 is from 0°C to 70°C. - What types of output operations are supported by the TL494?
The TL494 supports both push-pull and single-ended output operations. - What is the purpose of the dead-time control comparator in the TL494?
The dead-time control comparator provides approximately 5% dead time to prevent both outputs from being pulsed twice during push-pull operation. - Can the TL494 be used in synchronous multiple-rail power supplies?
Yes, the TL494 can be used to drive common circuits in synchronous multiple-rail power supplies. - What are the common-mode voltage ranges of the error amplifiers in the TL494?
The error amplifiers in the TL494 have a common-mode voltage range from –0.3 V to VCC – 2 V. - What is the maximum short-circuit output current of the TL494's reference regulator?
The maximum short-circuit output current of the TL494's reference regulator is 25 mA.
