Overview
The UC3844AD8TRG4 is a current-mode PWM controller from Texas Instruments, part of the UCx84x family. 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 operates within a temperature range of 0°C to 70°C, making it suitable for a variety of power supply applications. The device features a high level of integration, including an undervoltage lockout (UVLO), automatic feedforward compensation, pulse-by-pulse current limiting, and a totem-pole output stage capable of sourcing or sinking high-peak currents.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| VCC | - | - | 30 | V |
| Output Drive Current | - | - | ±1 A | - |
| Oscillator Frequency | 100 | - | 500 | kHz |
| Operating Temperature | 0 | - | 70 | °C |
| UVLO Enable Threshold | 14.5 | 16 | 17.5 | V |
| UVLO Off Threshold | 10 | - | 16 | V |
| Reference Voltage | 4.9 | 5 | 5.1 | V |
| Error Amplifier Output Sink Current | - | - | 10 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
- 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
- Off-line power supplies
- DC-DC converters
Q & A
- What is the operating temperature range of the UC3844AD8TRG4?
The UC3844AD8TRG4 operates within a temperature range of 0°C to 70°C. - What is the maximum output drive current of the UC3844AD8TRG4?
The maximum output drive current is ±1 A. - What is the oscillator frequency range of the UC3844AD8TRG4?
The oscillator frequency range is from 100 kHz to 500 kHz. - What type of output stage does the UC3844AD8TRG4 have?
The UC3844AD8TRG4 has a high-current totem-pole output stage. - What is the purpose of the undervoltage lockout (UVLO) feature?
The UVLO feature prevents the device from operating below a certain voltage threshold, ensuring safe startup and operation. - Can the UC3844AD8TRG4 be used in DC-DC converters?
Yes, the UC3844AD8TRG4 is suitable for DC-DC converter applications. - What is the reference voltage of the UC3844AD8TRG4?
The reference voltage is typically 5 V, with a range of 4.9 V to 5.1 V. - How does the automatic feedforward compensation work?
The automatic feedforward compensation helps in stabilizing the power converter voltage-feedback loop. - What is the maximum junction temperature of the UC3844AD8TRG4?
The maximum junction temperature is 150°C. - What are the package options available for the UC3844AD8TRG4?
The device is available in SOIC, PDIP, and CFP packages.
