Overview
The UC3844DTRG4 is a fixed-frequency current-mode PWM (Pulse Width Modulation) controller produced by Texas Instruments. It is part of the UCx84x family of control integrated circuits, designed to implement off-line and DC-to-DC fixed-frequency current-mode control schemes with a minimal number of external components. This device is optimized for various power supply applications, including off-line and DC-to-DC converters, and offers a range of features that enhance its performance and reliability.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Temperature Range | 0 | - | 70 | °C |
| Supply Voltage (VCC) | - | - | 30 | V |
| Start-Up Current | - | < 1 | - | mA |
| Operating Frequency | 47 | 52 | 57 | kHz |
| Reference Output Voltage (VREF) | 4.90 | 5.00 | 5.10 | V |
| Maximum Duty Cycle | 47% | 48% | 50% | % |
| UVLO Start Threshold (VTH(ST)) | 14.5 | 16.0 | 17.5 | V |
| UVLO Off Threshold (VCCOFF) | 8.5 | 10.0 | 11.5 | V |
Key Features
- Optimized for off-line and DC-to-DC converters
- Low start-up current (< 1mA)
- 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 500kHz operation
- Error amplifier with low output resistance
Applications
The UC3844DTRG4 is suitable for a variety of power supply applications, including:
- Off-line power supplies
- DC-to-DC converters
- Switch-mode power supplies (SMPS)
- High-efficiency power conversion systems
Q & A
- What is the operating temperature range of the UC3844DTRG4?
The operating temperature range is from 0°C to 70°C.
- What is the start-up current of the UC3844DTRG4?
The start-up current is less than 1mA.
- What is the maximum operating frequency of the UC3844DTRG4?
The maximum operating frequency is up to 500kHz.
- What are the UVLO thresholds for the UC3844DTRG4?
The UVLO start threshold is between 14.5V to 17.5V, and the UVLO off threshold is between 8.5V to 11.5V.
- What is the maximum duty cycle of the UC3844DTRG4?
The maximum duty cycle is 50%.
- What type of output stage does the UC3844DTRG4 have?
The UC3844DTRG4 has a high-current totem-pole output stage designed to source or sink high-peak current.
- Is the UC3844DTRG4 suitable for driving N-channel MOSFETs?
Yes, the output stage is suitable for driving N-channel MOSFETs).
- What is the reference output voltage of the UC3844DTRG4?
The reference output voltage (VREF) is between 4.90V to 5.10V).
- Does the UC3844DTRG4 have undervoltage lockout with hysteresis?
Yes, it features undervoltage lockout with hysteresis).
- What is the power dissipation at TA ≤ 25°C for the 8-SOP package?
The power dissipation at TA ≤ 25°C for the 8-SOP package is 460mW).
