Overview
The UC2844DG4 is a current-mode PWM controller from Texas Instruments, part of the UCx84x series. This integrated circuit is designed to implement off-line and DC-to-DC fixed-frequency current-mode control schemes with a minimal number of external components. It features a low start-up current of less than 1 mA, automatic feedforward compensation, pulse-by-pulse current limiting, and enhanced load-response characteristics. The device includes an undervoltage lockout (UVLO) with hysteresis, double-pulse suppression, and a high-current totem-pole output stage suitable for driving N-channel MOSFETs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC | - | - | 30 | V |
| VFB and VISENSE | -0.3 | - | 6.3 | V |
| Output Drive Current | - | - | ±1 A | A |
| Error Amplifier Output Sink Current | - | - | 10 mA | mA |
| Oscillator Frequency | 100 | - | 500 | kHz |
| Operating Temperature Range | -40 | - | 85 | °C |
| Reference Voltage | 4.95 | 5 | 5.05 | V |
| UVLO Enable Threshold | 15 | 16 | 17 | V |
| UVLO Off Threshold | 9 | 10 | 11 | V |
| Maximum Duty Cycle | 46% | 48% | 50% | % |
| Start-up Current | 0.5 | 1 | - | mA |
Key Features
- Optimized for off-line and DC-to-DC converters
- 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 stage
- Internally trimmed bandgap reference
- Up to 500-kHz operation
- Error amplifier with low output resistance
Applications
- Switching regulators of any polarity
- Transformer-coupled DC-DC converters
Q & A
- What is the UC2844DG4 used for?
The UC2844DG4 is used for implementing off-line and DC-to-DC fixed-frequency current-mode control schemes in power supply applications. - What is the operating temperature range of the UC2844DG4?
The operating temperature range of the UC2844DG4 is from -40°C to 85°C. - What is the maximum duty cycle of the UC2844DG4?
The maximum duty cycle of the UC2844DG4 is up to 50%. - What is the start-up current of the UC2844DG4?
The start-up current of the UC2844DG4 is less than 1 mA. - What type of output stage does the UC2844DG4 have?
The UC2844DG4 has a high-current totem-pole output stage suitable for driving N-channel MOSFETs. - What is the purpose of the undervoltage lockout (UVLO) in the UC2844DG4?
The UVLO in the UC2844DG4 ensures that the device operates only when the input voltage is within a safe range, preventing damage from low voltage conditions. - What is the oscillator frequency range of the UC2844DG4?
The oscillator frequency range of the UC2844DG4 is from 100 kHz to 500 kHz. - What type of compensation does the UC2844DG4 offer?
The UC2844DG4 offers automatic feedforward compensation and allows for external compensation components to be connected to the error amplifier. - What are some common applications of the UC2844DG4?
Common applications include switching regulators of any polarity and transformer-coupled DC-DC converters. - How does the UC2844DG4 handle current limiting?
The UC2844DG4 features pulse-by-pulse current limiting to protect against overcurrent conditions.
