ON Semiconductor
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UC3843BVN
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UC3843BVN

Product Overview

  • Category: Integrated Circuit
  • Use: Voltage Mode PWM Controller
  • Characteristics: High Performance, Current Mode Control, Adjustable Frequency, Soft Start, Overcurrent Protection
  • Package: PDIP-8, SOIC-8
  • Essence: UC3843BVN is a voltage mode PWM controller designed for power supply applications.
  • Packaging/Quantity: Available in tubes or reels, with 50 units per tube/reel.

Specifications

  • Input Voltage Range: 7.6V to 30V
  • Output Voltage Range: 0V to 5.1V
  • Operating Temperature Range: -40°C to +85°C
  • Switching Frequency: Adjustable up to 500kHz
  • Maximum Duty Cycle: 100%
  • Output Current: Up to 1A

Pin Configuration

The UC3843BVN has the following pin configuration:

  1. VREF: Reference Voltage Output
  2. COMP: Error Amplifier Output
  3. FB: Feedback Input
  4. GND: Ground
  5. CS: Current Sense Input
  6. RT/CT: Timing Components Connection
  7. OUT: Output
  8. VCC: Supply Voltage Input

Functional Features

  • Voltage Mode PWM Control
  • Adjustable Frequency
  • Soft Start Functionality
  • Overcurrent Protection
  • Error Amplifier for Precise Regulation
  • Current Sensing for Accurate Current Limiting

Advantages and Disadvantages

Advantages

  • High Performance and Reliability
  • Wide Input Voltage Range
  • Adjustable Switching Frequency
  • Efficient Power Conversion
  • Overcurrent Protection Enhances Safety

Disadvantages

  • Limited Output Current (Up to 1A)
  • Requires External Timing Components
  • Not Suitable for High Power Applications

Working Principles

The UC3843BVN operates on the voltage mode control principle. It compares the feedback voltage (FB) with a reference voltage (VREF) to generate an error signal. This error signal is then amplified and used to control the duty cycle of the PWM signal. By adjusting the duty cycle, the output voltage can be regulated.

The IC also incorporates a current sense input (CS) that monitors the current flowing through the power switch. If the current exceeds a set limit, the IC triggers the overcurrent protection circuitry, shutting down the power supply temporarily.

Detailed Application Field Plans

The UC3843BVN is commonly used in various power supply applications, including:

  1. Switching Mode Power Supplies (SMPS)
  2. DC-DC Converters
  3. LED Drivers
  4. Battery Chargers
  5. Offline Flyback Converters
  6. Telecom Power Supplies

Detailed and Complete Alternative Models

Some alternative models to UC3843BVN include:

  1. UC3842BVN: Similar specifications but with lower output current capability.
  2. UC3844BVN: Higher output current capability and additional features like synchronization.
  3. UC3845BVN: Similar to UC3844BVN but with higher switching frequency capability.

These alternative models provide flexibility in choosing the right controller based on specific application requirements.

In conclusion, the UC3843BVN is a versatile voltage mode PWM controller suitable for various power supply applications. Its high performance, adjustable frequency, and overcurrent protection make it a reliable choice for efficient power conversion. However, its limited output current and need for external timing components should be considered when selecting this IC for high-power applications.

Noem 10 veelgestelde vragen en antwoorden met betrekking tot de toepassing van UC3843BVN in technische oplossingen

Sure! Here are 10 common questions and answers related to the application of UC3843BVN in technical solutions:

  1. Q: What is UC3843BVN? A: UC3843BVN is a voltage mode PWM controller IC commonly used in power supply applications.

  2. Q: What is the operating voltage range of UC3843BVN? A: The operating voltage range of UC3843BVN is typically between 8V and 35V.

  3. Q: What is the maximum switching frequency supported by UC3843BVN? A: UC3843BVN can support a maximum switching frequency of up to 500kHz.

  4. Q: Can UC3843BVN be used in both buck and boost converter topologies? A: Yes, UC3843BVN can be used in both buck and boost converter topologies.

  5. Q: What is the purpose of the error amplifier in UC3843BVN? A: The error amplifier in UC3843BVN compares the feedback voltage with the reference voltage to regulate the output voltage.

  6. Q: How does UC3843BVN provide overcurrent protection? A: UC3843BVN provides overcurrent protection by monitoring the current flowing through the power MOSFET and limiting it when it exceeds a set threshold.

  7. Q: Can UC3843BVN be used in high-power applications? A: Yes, UC3843BVN can be used in high-power applications by using external power MOSFETs capable of handling the required power levels.

  8. Q: Does UC3843BVN have built-in soft-start functionality? A: No, UC3843BVN does not have built-in soft-start functionality. However, an external soft-start circuit can be added if required.

  9. Q: What is the purpose of the oscillator in UC3843BVN? A: The oscillator in UC3843BVN generates a fixed frequency square wave that controls the switching of the power MOSFET.

  10. Q: Can UC3843BVN operate in continuous or discontinuous conduction mode? A: UC3843BVN can operate in both continuous and discontinuous conduction modes, depending on the load conditions and converter topology.

Please note that these answers are general and may vary depending on specific application requirements and circuit design considerations.