Overview
The UC3843AD2, produced by onsemi, is a fixed frequency current-mode PWM (Pulse Width Modulation) controller. This component is specifically designed for off-line and DC to DC converter applications, requiring minimal external components. Introduced in 1999, it has been a staple in power management circuits due to its robust features and reliability.
Key Specifications
| Parameter | Symbol | Value | Unit |
|---|---|---|---|
| Supply Voltage | VCC | 30 | V |
| Output Current | IO | ±1 | A |
| Analog Inputs (Pin 2, 3) | V(ANA) | -0.3 to 6.3 | V |
| Error Amp Output Sink Current | ISINK (E.A) | 10 | mA |
| Power Dissipation at TA≤25°C (14SOP) | PD | 680 | mW |
| Storage Temperature Range | TSTG | -65 ~ +150 | °C |
| Operating Frequency | f | 47 to 57 | kHz |
| Maximum Duty Cycle | D(Max) | 95 to 100 | % |
| Start-Up Current | IST | 0.45 to 1 | mA |
| Operating Supply Current | ICC(OPR) | 14 to 17 | mA |
Key Features
- Low Start-Up Current: The UC3843AD2 has a low start-up current, which is beneficial for power-saving designs.
- Maximum Duty Clamp: It features a maximum duty clamp, ensuring stable and controlled output.
- UVLO With Hysteresis: The component includes Under Voltage Lock Out (UVLO) with hysteresis, providing protection against voltage fluctuations.
- Operating Frequency up to 500kHz: The controller can operate at frequencies up to 500kHz, making it suitable for high-frequency applications.
- Trimmed Oscillator: A trimmed oscillator ensures precise duty cycle control.
- Temperature Compensated Reference: The integrated temperature compensated reference ensures stable operation over a range of temperatures.
- High Gain Error Amplifier: A high gain error amplifier is included for accurate feedback control.
- Current Sensing Comparator: The component features a current sensing comparator for efficient current control.
- High Current Totem-Pole Output: It has a high current totem-pole output for driving power MOSFETs effectively.
Applications
The UC3843AD2 is widely used in various power management applications, including:
- Off-Line Converters: Suitable for designing off-line power supplies due to its robust features and high reliability.
- DC to DC Converters: Ideal for DC to DC converter applications requiring high efficiency and minimal external components.
- Power Supplies: Used in the design of power supplies for various electronic devices.
- Industrial Power Systems: Employed in industrial power systems where high reliability and efficiency are crucial.
Q & A
- What is the UC3843AD2 used for?
The UC3843AD2 is a fixed frequency current-mode PWM controller used in off-line and DC to DC converter applications.
- What is the maximum operating frequency of the UC3843AD2?
The UC3843AD2 can operate at frequencies up to 500kHz.
- What is the UVLO threshold for the UC3843AD2?
The UVLO thresholds for the UC3843AD2 are 8.5V (on) and 7.9V (off).
- What is the maximum duty cycle of the UC3843AD2?
The maximum duty cycle for the UC3843AD2 is 95% to 100%.
- What is the start-up current of the UC3843AD2?
The start-up current of the UC3843AD2 is between 0.45mA and 1mA.
- What is the operating supply current of the UC3843AD2?
The operating supply current of the UC3843AD2 is between 14mA and 17mA.
- What are the key features of the UC3843AD2?
The key features include low start-up current, maximum duty clamp, UVLO with hysteresis, trimmed oscillator, temperature compensated reference, high gain error amplifier, current sensing comparator, and high current totem-pole output.
- What are the typical applications of the UC3843AD2?
The UC3843AD2 is typically used in off-line converters, DC to DC converters, power supplies, and industrial power systems.
- What is the storage temperature range for the UC3843AD2?
The storage temperature range for the UC3843AD2 is -65°C to +150°C.
- What is the maximum power dissipation at TA≤25°C for the 14SOP package?
The maximum power dissipation at TA≤25°C for the 14SOP package is 680mW.
