Overview
The UC3843ANG4 is a fixed-frequency current-mode PWM (Pulse Width Modulation) controller produced by Texas Instruments. This integrated circuit is specifically designed for off-line and DC-to-DC converter applications, requiring a minimal number of external components. It is part of the UCx84x family, which offers a range of features and specifications tailored for various power supply designs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | - | - | 30 | V |
| Output Current (IO) | - | - | ±1 A | A |
| Analog Input Voltage (VANA) | -0.3 | - | 6.3 | V |
| Error Amp Output Sink Current (ISINK) | - | - | 10 mA | mA |
| Operating Frequency (fOSC) | 100 kHz | - | 500 kHz | kHz |
| Reference Output Voltage (VREF) | 4.9 V | 5 V | 5.1 V | V |
| Start-Up Current (IST) | - | - | 1 mA | mA |
| Operating Supply Current (ICC) | - | 14 mA | 17 mA | mA |
| Maximum Duty Cycle (DMAX) | 95% | 97% | 100% | % |
| Minimum Duty Cycle (DMIN) | - | - | 0% | % |
| Operating Temperature Range | 0°C | - | 70°C | °C |
| Storage Temperature Range | -65°C | - | 150°C | °C |
Key Features
- Low start-up current (< 1 mA)
- Automatic feedforward compensation
- Pulse-by-pulse current limiting
- Enhanced load-response characteristics
- Undervoltage lockout with hysteresis
- Double-pulse suppression
- High-current totem-pole output for driving N-channel MOSFETs
- Internally trimmed bandgap reference
- Operating frequency up to 500 kHz
- Error amplifier with low output resistance
Applications
- Switching regulators of any polarity
- Transformer-coupled DC-DC converters
- Off-line power supplies
- DC-DC converters
- Isolated-flyback power supply controllers for Constant-Voltage (CV) and Constant-Current (CC) output regulation
Q & A
- What is the UC3843ANG4 used for?
The UC3843ANG4 is used for off-line and DC-to-DC converter applications, providing fixed-frequency current-mode PWM control.
- What is the operating frequency range of the UC3843ANG4?
The operating frequency range is from 100 kHz to 500 kHz.
- What is the maximum duty cycle for the UC3843ANG4?
The maximum duty cycle for the UC3843ANG4 is 95% to 100%.
- What is the start-up current of the UC3843ANG4?
The start-up current is less than 1 mA.
- What are the key features of the UC3843ANG4?
Key features include low start-up current, automatic feedforward compensation, pulse-by-pulse current limiting, undervoltage lockout with hysteresis, and a high-current totem-pole output.
- What is the operating temperature range for the UC3843ANG4?
The operating temperature range is from 0°C to 70°C.
- What types of applications can the UC3843ANG4 be used in?
It can be used in switching regulators, transformer-coupled DC-DC converters, off-line power supplies, and DC-DC converters.
- What is the reference output voltage of the UC3843ANG4?
The reference output voltage is between 4.9 V and 5.1 V.
- How does the undervoltage lockout (UVLO) work in the UC3843ANG4?
The UVLO has a start threshold and an off threshold with hysteresis to prevent the device from operating below a certain voltage level.
- What is the maximum output current of the UC3843ANG4?
The maximum output current is ±1 A.
