Overview
The TL494IDRE4, produced by Texas Instruments, is a pulse-width-modulation (PWM) control circuit integrated into a single chip. It is primarily designed for power-supply control and offers the flexibility to tailor the power-supply control circuitry to specific applications. 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, 5%-precision regulator. This architecture allows for easy synchronization in synchronous multiple-rail power supplies and provides stable output control with various operational modes.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Output Voltage (REF) | 4.75 | 5 | 5.25 | V |
| Input Regulation | - | - | 25 mV | - |
| Output Regulation | - | - | 15 mV | - |
| Output Voltage Change with Temperature | - | - | 10 mV/V | - |
| Short-Circuit Output Current | - | - | 25 mA | - |
| Oscillator Frequency | - | 10 kHz | - | - |
| Operating Temperature Range | -40 | - | 85 | °C |
| Supply Current (Standby) | 6 | 10 | 15 | mA |
Key Features
- Complete PWM Power-Control Circuitry on a single chip
- 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 Synchronization in Synchronous Multiple-Rail Power Supplies
Applications
- Desktop PCs
- Microwave Ovens
- Power Supplies: AC/DC, Isolated, With PFC, > 90 W
- Server PSUs
Q & A
- What is the primary function of the TL494IDRE4?
The TL494IDRE4 is a pulse-width-modulation (PWM) control circuit primarily designed for power-supply control.
- What are the key components of the TL494IDRE4?
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, 5%-precision regulator.
- What is the operating temperature range of the TL494IDRE4?
The TL494IDRE4 operates from –40°C to 85°C.
- Can the oscillator in the TL494IDRE4 be bypassed?
Yes, 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 are supported by the TL494IDRE4?
The device supports both single-ended and push-pull output operations.
- What is the purpose of the dead-time control comparator?
The dead-time control comparator provides approximately 5% dead time and helps in controlling the output pulses.
- How does the internal 5-V reference regulator function?
The internal 5-V reference regulator provides a stable 5-V supply with 5% tolerance and acts as a preregulator for the device's internal circuits.
- What are some common applications of the TL494IDRE4?
Common applications include desktop PCs, microwave ovens, power supplies (AC/DC, isolated, with PFC), and server PSUs.
- Can the TL494IDRE4 be used in synchronous multiple-rail power supplies?
Yes, the device's architecture allows for easy synchronization in synchronous multiple-rail power supplies.
- What is the maximum output current of the uncommitted output transistors?
The uncommitted output transistors can sink or source up to 200 mA of current.
