Overview
The UC3526ADWTR, produced by Texas Instruments, is an improved-performance pulse-width modulator (PWM) circuit. It is part of the UC3526A series, designed for high-frequency operation and enhanced performance over earlier non-‘A’ versions. This component is suitable for a wide range of applications requiring precise PWM control, such as DC-DC converters, power supplies, and motor control systems.
The UC3526ADWTR offers several key improvements, including a more accurate oscillator, reduced circuit delays, and an improved output stage with minimal cross-conduction current. It also features a precision band-gap reference generator, reduced overall supply current, and thermal shutdown protection.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Operating Voltage Range | 7 | - | 35 | V |
| Oscillator Frequency Range | 1 Hz | - | 600 kHz | - |
| Oscillator Timing Resistor Range | 2 kΩ | - | 150 kΩ | - |
| Oscillator Timing Capacitor Range | 400 pF | - | 20 µF | - |
| Output Current (Source/Sink) | - | - | 200 mA | - |
| Operating Ambient Temperature Range | -25°C | - | 85°C | - |
| Power Dissipation at TA = +25°C | - | - | 1000 mW | - |
| Storage Temperature Range | -65°C | - | 150°C | - |
| Lead Temperature (soldering, 10 seconds) | - | - | 300°C | - |
Key Features
- Precision Band-Gap Reference: Internally trimmed to ±1% accuracy, providing a stable reference voltage.
- High Frequency Operation: Oscillator frequency up to 600 kHz.
- Dual 200mA Source/Sink Outputs: Capable of sourcing and sinking high currents.
- Minimum Output Cross-Conduction: Improved design reduces cross-conduction current to less than 50ns.
- Double-Pulse Suppression Logic: Prevents double-pulsing in the output stage.
- Under-Voltage Lockout: Protects the device and power devices from inadequate supply voltage.
- Programmable Soft-Start: Protects power transistors and rectifier diodes from high current surges during power supply turn-on.
- Thermal Shutdown Protection: Protects the device from overheating.
- TTL/CMOS Compatible Logic Ports: Bi-directional ports compatible with TTL and 5V CMOS logic.
Applications
- DC-DC Converters: Suitable for buck, boost, and flyback converters due to its high-frequency operation and precision control.
- Power Supplies: Used in switched-mode power supplies for efficient and reliable operation.
- Motor Control Systems: Ideal for motor control applications requiring precise PWM control.
- Audio and Lighting Systems: Can be used in audio amplifiers and lighting systems that require high-frequency PWM.
Q & A
- What is the operating voltage range of the UC3526ADWTR?
The operating voltage range is from 7V to 35V.
- What is the maximum oscillator frequency of the UC3526ADWTR?
The maximum oscillator frequency is 600 kHz.
- What is the output current capability of the UC3526ADWTR?
The device can source and sink up to 200 mA.
- Does the UC3526ADWTR have thermal shutdown protection?
Yes, it includes thermal shutdown protection to prevent overheating.
- Is the UC3526ADWTR compatible with TTL and CMOS logic?
Yes, it has TTL/CMOS compatible logic ports.
- What is the purpose of the under-voltage lockout feature in the UC3526ADWTR?
The under-voltage lockout feature protects the device and the power devices it controls from inadequate supply voltage.
- How does the soft-start feature work in the UC3526ADWTR?
The soft-start feature protects the power transistors and rectifier diodes from high current surges during power supply turn-on by gradually increasing the duty cycle.
- What is the storage temperature range for the UC3526ADWTR?
The storage temperature range is from -65°C to 150°C.
- Can the UC3526ADWTR be used in motor control systems?
Yes, it is suitable for motor control systems requiring precise PWM control.
- How do you program the oscillator frequency and deadtime in the UC3526ADWTR?
The oscillator frequency and deadtime are programmed using the RT, CT, and RD components.
