Overview
The UC3843AD8TRG4 is a current-mode PWM (Pulse Width Modulation) controller produced by Texas Instruments. This component is part of the UCx84x family, which is optimized for off-line and DC-DC converter applications. The UC3843A is specifically designed to operate within a temperature range of 0°C to 70°C, making it suitable for a variety of power supply designs.
It features a high-speed PWM capability with switching frequencies up to 500 kHz, an onboard totem-pole gate driver, and an undervoltage lockout (UVLO) with a start-up current of less than 1 mA. This controller is ideal for applications requiring precise control over power conversion processes.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Temperature Range | 0 | - | 70 | °C |
| UVLO Start Threshold | 7.8 | 8.4 | 9 | V |
| UVLO Minimum Operation Voltage After Turn-On | 7 | 7.6 | 8.2 | V |
| Maximum Duty Cycle | - | - | 94% | - |
| Oscillator Frequency | 47 | 52 | 57 | kHz |
| Output Drive Current | - | - | ±1 A | - |
| Error Amplifier Output Sink Current | - | - | 10 mA | - |
| Output Voltage (VOUT) High | 5 | - | 6 V | - |
| Output Voltage (VOUT) Low | 0.7 | - | 1.1 V | - |
Key Features
- Current-Mode PWM Control: Optimized for off-line and DC-DC converters with a high-speed PWM capability up to 500 kHz.
- Undervoltage Lockout (UVLO): Features a start-up current of less than 1 mA and a UVLO start threshold of 7.8V to 9V.
- Totem-Pole Output Stage: Capable of sourcing or sinking high-peak current, suitable for driving N-channel MOSFETs.
- Precision Reference and Error Amplifier: Trimmed for accuracy with an open-loop gain of 80 dB and a common mode rejection ratio of 60 dB to 70 dB.
- Low Start-Up Current: Less than 0.5 mA, which is beneficial for power-saving designs.
- Thermal Stability: Operates within a temperature range of 0°C to 70°C, ensuring reliable performance in various environments.
Applications
- Off-Line Power Supplies: Ideal for isolated and non-isolated power supply designs, including flyback converters.
- DC-DC Converters: Suitable for a wide range of DC-DC conversion applications requiring high precision and reliability.
- High-Frequency Switching Applications: The 500 kHz switching frequency makes it suitable for high-frequency switching applications.
- Industrial and Consumer Electronics: Used in various industrial and consumer electronic devices that require efficient and reliable power management.
Q & A
- What is the operating temperature range of the UC3843AD8TRG4?
The UC3843AD8TRG4 operates within a temperature range of 0°C to 70°C.
- What is the maximum switching frequency of the UC3843AD8TRG4?
The UC3843AD8TRG4 can operate at switching frequencies up to 500 kHz.
- What is the UVLO start threshold for the UC3843AD8TRG4?
The UVLO start threshold for the UC3843AD8TRG4 is between 7.8V and 9V.
- What is the output drive current capability of the UC3843AD8TRG4?
The UC3843AD8TRG4 can source or sink up to ±1 A of peak current.
- What type of output stage does the UC3843AD8TRG4 have?
The UC3843AD8TRG4 features a totem-pole output stage suitable for driving N-channel MOSFETs.
- What is the typical application for the UC3843AD8TRG4?
The UC3843AD8TRG4 is typically used in off-line and DC-DC converter applications, including flyback converters and other high-frequency switching applications.
- What is the error amplifier's open-loop gain in the UC3843AD8TRG4?
The error amplifier in the UC3843AD8TRG4 has an open-loop gain of 80 dB.
- What is the common mode rejection ratio (CMRR) of the UC3843AD8TRG4?
The CMRR of the UC3843AD8TRG4 is between 60 dB and 70 dB.
- What are the package options available for the UC3843AD8TRG4?
The UC3843AD8TRG4 is available in various packages including SOIC (8), PDIP (8), and CFP (8).
- How does the UC3843AD8TRG4 handle thermal stability?
The UC3843AD8TRG4 is designed to ensure thermal stability with specified thermal metrics such as junction-to-ambient thermal resistance and junction-to-case thermal resistance.
