Overview
The TL494CN, 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 comprehensive set of features makes the TL494CN highly versatile for various power supply configurations.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Power Supply Voltage (VCC) | 42 | V |
| Collector Output Voltage (VC1, VC2) | 42 | V |
| Operating Temperature Range | 0 to 70°C (TL494), -40 to 85°C (TL494I) | °C |
| Oscillator Frequency (CT = 0.001 μF, RT = 30 kΩ) | 40 kHz | kHz |
| Standard Deviation of Frequency | 3.0% | % |
| Output Transistor Current Rating | 200 mA (sink or source) | mA |
| Reference Voltage (Vref) | 5 V ± 5% | V |
| Dead-Time Control | Approximately 5% dead time | % |
Key Features
- Complete PWM power-control circuitry on a single chip.
- Uncommitted output transistors rated for 200 mA sink or source current.
- Output control selects single-ended or push-pull operation.
- Internal circuitry prohibits double pulse at either output during push-pull operation.
- Variable dead time provides control over the 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
- Solar micro-inverters
- Washing machines: low-end and high-end
- E-bikes
- Power supplies: AC/DC, isolated, no PFC, < 90 W
- Telecom/server AC/DC supplies: dual controller, analog
- Smoke detectors
- Solar power inverters
Q & A
- What is the primary application of the TL494CN?
The TL494CN is primarily designed for power-supply control, offering flexibility in tailoring the power-supply control circuitry to specific applications.
- What are the key components of the TL494CN?
The TL494CN 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 TL494CN?
The TL494CN operates from 0°C to 70°C, while the TL494I operates from –40°C to 85°C.
- How is the oscillator frequency set in the TL494CN?
The oscillator frequency is programmed by selecting the timing components RT and CT.
- What is the output current rating of the TL494CN's output transistors?
The output transistors are rated for 200 mA sink or source current.
- Can the TL494CN be used in push-pull or single-ended output configurations?
Yes, the TL494CN can be configured for either push-pull or single-ended output operation through the output-control function.
- What is the purpose of the dead-time control comparator in the TL494CN?
The dead-time control comparator provides approximately 5% dead time and allows for variable dead time control over the total range.
- What is the stability of the internal 5-V reference regulator in the TL494CN?
The internal regulator maintains a stability of less than 25-mV variation over an input voltage range of 7 V to 40 V.
- Can the TL494CN be synchronized in multiple-rail power supplies?
Yes, the circuit architecture of the TL494CN allows for easy synchronization in synchronous multiple-rail power supplies.
- What are some common applications of the TL494CN?
Common applications include desktop PCs, microwave ovens, power supplies, server PSUs, solar micro-inverters, washing machines, e-bikes, and more.
- Is the TL494CN available in different package types?
Yes, the TL494CN is available in various package types such as SOIC, PDIP, SOP, and TSSOP.
