Overview
The TL594CDTB, produced by onsemi, is a precision switchmode pulse width modulation (PWM) control circuit. This device is designed primarily for switchmode power supply control and incorporates all the necessary functions for constructing a PWM control circuit on a single chip. It offers systems engineers the flexibility to tailor the power-supply control circuitry to specific applications. The TL594CDTB includes features such as two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC) comparator, a pulse-steering control flip-flop, a 5-V regulator with 1.5% accuracy, and undervoltage lockout control circuitry.
Key Specifications
| Specification | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Power Supply Voltage | VCC | 7.0 | 15 | 40 | V |
| Collector Output Voltage | VC1, VC2 | - | - | 40 | V |
| Collector Output Current (Each Transistor) | IC1, IC2 | - | - | 500 | mA |
| Amplifier Input Voltage Range | VIR | -0.3 | - | VCC - 2.0 | V |
| Oscillator Frequency | fosc | 1.0 | - | 300 | kHz |
| Timing Resistor | RT | 1.8 | - | 500 | kΩ |
| Timing Capacitor | CT | 0.0047 | - | 10 | μF |
Key Features
- Complete PWM Power-Control Circuitry: Includes all necessary functions for PWM control on a single chip.
- On-Chip Oscillator with Master or Slave Operation: Frequency-programmable by external components RT and CT.
- On-Chip Error Amplifiers: With a common-mode voltage range of -0.3 V to VCC - 2 V.
- On-Chip 5.0 V Reference, 1.5% Accuracy: Provides a stable reference voltage.
- Adjustable Deadtime Control: Variable dead time control for output pulse modulation.
- Uncommitted Output Transistors: Rated to 500 mA source or sink, with common-emitter or emitter-follower output capability.
- Output Control for Push-Pull or Single-Ended Operation: Selection by means of the output-control function.
- Undervoltage Lockout: Locks the outputs off until the internal circuitry is operational.
- Pb-Free Packages are Available: Compliant with RoHS standards.
Applications
- Off-line Power Supply: Suitable for various power supply configurations.
- Buck Converter: Can be used in buck converter applications.
- Vehicle Power Adapter (VPA): Applicable in automotive power systems.
- LED Lighting: Can be used in LED lighting control circuits.
- Synchronous Multiple-Rail Power Supplies: Can drive common circuitry in these applications.
Q & A
- What is the primary function of the TL594CDTB?
The TL594CDTB is a precision switchmode pulse width modulation (PWM) control circuit designed primarily for switchmode power supply control.
- What is the range of the power supply voltage for the TL594CDTB?
The power supply voltage range is from 7.0 V to 40 V.
- What is the maximum collector output current for each transistor?
The maximum collector output current for each transistor is 500 mA.
- Can the on-chip oscillator 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 is the accuracy of the on-chip 5.0 V reference voltage?
The on-chip 5.0 V reference voltage has an accuracy of 1.5%.
- What types of output operations are supported by the TL594CDTB?
The device supports push-pull or single-ended output operations.
- What is the purpose of the undervoltage lockout control circuit?
The undervoltage lockout control circuit locks the outputs off until the internal circuitry is operational.
- Is the TL594CDTB available in Pb-free packages?
Yes, the TL594CDTB is available in Pb-free packages and is RoHS compliant.
- What is the maximum oscillator frequency of the TL594CDTB?
The maximum oscillator frequency is 300 kHz.
- What are some common applications of the TL594CDTB?
Common applications include off-line power supplies, buck converters, vehicle power adapters, LED lighting, and synchronous multiple-rail power supplies.
