Overview
The TL494IDRG4, produced by Texas Instruments, is a highly integrated pulse-width-modulation (PWM) control circuit designed primarily for power-supply control applications. This device incorporates all the necessary functions for constructing a PWM control circuit on a single chip, offering flexibility to tailor the power-supply control circuitry to specific applications.
The TL494IDRG4 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 precision regulator. It supports both push-pull and single-ended output operations and features uncommitted output transistors capable of sinking or sourcing up to 200 mA of current.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Input Voltage Range (VCC) | 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/°C |
| Short-Circuit Output Current (REF = 0 V) | - | - | 25 | mA |
| Oscillator Frequency (CT = 0.01 μF, RT = 12 kΩ) | - | - | 300 kHz | Hz |
| Rise Time (Common-Emitter Configuration) | 100 | 200 | - | ns |
| Fall Time (Common-Emitter Configuration) | 25 | 100 | - | ns |
| Operating Temperature Range | -40 | - | 85 | °C |
Key Features
- Complete PWM power-control circuitry on a single chip.
- 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 for external control.
- A dead-time control (DTC) comparator with a fixed offset providing approximately 5% dead time.
- A pulse-steering control flip-flop for directing modulated pulses to output transistors.
- A 5-V, 5%-precision regulator for stable reference voltage.
- Uncommitted output transistors capable of sinking or sourcing up to 200 mA of current.
- Support for both push-pull and single-ended output operations.
- Operating temperature range from –40°C to 85°C for the TL494I device.
Applications
- Power-supply control circuits, including switching power supplies and DC-DC converters.
- Synchronous multiple-rail power supplies.
- Motor control systems requiring PWM signals.
- High-frequency switching applications.
- General-purpose PWM control in various electronic systems.
Q & A
- What is the primary function of the TL494IDRG4?
The TL494IDRG4 is a pulse-width-modulation (PWM) control circuit designed primarily for power-supply control applications.
- What are the key components of the TL494IDRG4?
The device 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 precision regulator.
- What is the output current capability of the TL494IDRG4?
The uncommitted output transistors can sink or source up to 200 mA of current.
- Can the TL494IDRG4 be used in high-temperature environments?
Yes, the TL494I device is characterized for operation from –40°C to 85°C.
- How can the oscillator in the TL494IDRG4 be controlled?
The on-chip oscillator can be bypassed by terminating RT to the reference output and providing a sawtooth input to CT.
- What types of output operations does the TL494IDRG4 support?
The device supports both push-pull and single-ended output operations.
- What is the typical frequency range of the oscillator in the TL494IDRG4?
The oscillator frequency can range up to 300 kHz.
- How does the dead-time control comparator function in the TL494IDRG4?
The dead-time control comparator has a fixed offset that provides approximately 5% dead time.
- What is the purpose of the pulse-steering flip-flop in the TL494IDRG4?
The pulse-steering flip-flop alternately directs the modulated pulse to each of the two output transistors.
- Can the TL494IDRG4 be used in synchronous multiple-rail power supplies?
Yes, the device can drive common circuits in synchronous multiple-rail power supplies.
