Overview
The TL494CNSRG4, 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 TL494CNSRG4 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 | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 7 | - | 40 | V |
| VI Amplifier Input Voltage | -0.3 | - | VCC - 2 | V |
| VO Collector Output Voltage | - | - | 40 | V |
| Collector Output Current (each transistor) | - | - | 200 | mA |
| fOSC Oscillator Frequency | 1 | - | 300 | kHz |
| CT Timing Capacitor | 0.47 | - | 10000 | nF |
| RT Timing Resistor | 1.8 | - | 500 | kΩ |
| Output Voltage (REF) | 4.75 | 5 | 5.25 | V |
| Operating Free-Air Temperature (TL494C) | 0 | - | 70 | °C |
| Operating Free-Air Temperature (TL494I) | -40 | - | 85 | °C |
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
- On-chip Adjustable Oscillator and Dead-Time Control Comparator
- Pulse-Steering Control Flip-Flop and Error Amplifiers
Applications
The TL494CNSRG4 is primarily used in power-supply control applications, including:
- Switch-Mode Power Supplies
- Synchronous Multiple-Rail Power Supplies
- DC-DC Converters
- Motor Control Systems
- Other applications requiring PWM control
Q & A
- What is the primary function of the TL494CNSRG4?
The TL494CNSRG4 is a pulse-width-modulation (PWM) control circuit primarily designed for power-supply control.
- What are the key components of the TL494CNSRG4?
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 types of output operations does the TL494CNSRG4 support?
The TL494CNSRG4 supports both push-pull and single-ended output operations.
- What is the maximum current that the output transistors can handle?
The uncommitted output transistors can sink or source up to 200 mA of current.
- How can the oscillator be configured?
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.
- What is the operating temperature range for the TL494C and TL494I devices?
The TL494C operates from 0°C to 70°C, while the TL494I operates from –40°C to 85°C.
- What is the purpose of the dead-time control comparator?
The dead-time control comparator has a fixed offset that provides approximately 5% dead time.
- Can the TL494CNSRG4 be synchronized with other circuits?
Yes, the circuit architecture of the TL494CNSRG4 allows for easy synchronization.
- What is the precision of the internal 5-V reference supply?
The internal regulator provides a stable 5-V reference supply with a 5% tolerance.
- What are some common applications of the TL494CNSRG4?
Common applications include switch-mode power supplies, synchronous multiple-rail power supplies, DC-DC converters, and motor control systems.
