UC3842BDTR

The UC3842BDTR is a high-performance, fixed-frequency current-mode PWM controller integrated circuit (IC) designed specifically for offline and DC-to-DC converter applications. It offers a minimal external component count, making it an ideal choice for power supply designers looking to balance good electrical performance and cost-effectiveness.

Key Features:

1. Current-Mode Control: The UC3842BDTR employs current-mode control, which provides several performance advantages over traditional voltage-mode control. It allows for faster transient response and improved load regulation.
2. Fixed Frequency Operation: The IC operates at a fixed frequency, typically 500kHz, making it easier to design and filter the output of the power supply.
3. Internal Oscillator: The UC3842BDTR features an internally trimmed oscillator for precise duty cycle control. The frequency of the oscillator can be adjusted by external components connected to the RT/CT pins.
4. Temperature-Compensated Reference: The IC includes a temperature-compensated reference voltage, which ensures stable operation over a wide temperature range.
5. High Gain Error Amplifier: The on-chip error amplifier provides high gain for precise feedback control of the output voltage.
6. PWM Comparator and Latch: The PWM comparator compares the error amplifier’s output to a sawtooth waveform generated by the oscillator, and the result is latched to control the output pulse width.
7. Under-Voltage Lockout (UVLO): The UC3842BDTR features UVLO thresholds of 16V (on) and 10V (off), protecting the IC and the power supply from damage due to low input voltage.
8. High Current Totem Pole Output: The output stage is designed to drive high peak currents, making it suitable for driving N-channel MOSFETs in power supply circuits.
9. Package Type: The UC3842BDTR is typically packaged in a surface-mount SOIC-8 or DIP-8 package, depending on the specific version.

Applications:

The UC3842BDTR is ideal for use in a wide range of power supply applications, including:

• Offline power supplies
• DC-to-DC converters
• Battery chargers
• LED drivers
• Motor control circuits

In summary, the UC3842BDTR is a versatile and high-performance PWM controller IC that offers a combination of features that make it an excellent choice for power supply designers. Its current-mode control, fixed frequency operation, and internal components provide robust and reliable performance, while its compact package makes it easy to integrate into various systems.