Overview
The UC2844AQDR, produced by Texas Instruments, is a high-performance fixed-frequency current-mode controller. It is part of the UCx84x series of control integrated circuits, designed to implement off-line or DC-to-DC fixed-frequency current-mode control schemes with a minimal number of external components. This controller is optimized for both off-line and DC-to-DC converters, offering a range of features that enhance its performance and reliability.
Key Specifications
| Parameter | Symbol | Min | Max | Unit | |
|---|---|---|---|---|---|
| Supply Voltage (Low Impedance Source) | VCC | - | - | 30 | V |
| Supply Voltage (ICC < 30mA) | VCC | - | - | Self Limiting | V |
| Error Amp Output Sink Current | ISINK | - | - | 10 | mA |
| Output Current, Source or Sink | IOUT | - | - | 1.0 | A |
| Output Energy (Capacitive Load per cycle) | W | - | - | 5.0 | μJ |
| Power Dissipation (DIP-8) | PD | - | - | 1250 | mW |
| Power Dissipation (SOP-8) | PD | - | - | 800 | mW |
| Junction Temperature | TJ | - | - | 150 | °C |
| Operating Temperature | TOPR | -40 | - | 85 | °C |
| Storage Temperature | TSTG | -65 | - | 150 | °C |
| Startup Threshold (UC2844) | VTHR | 14.5 | 16.0 | 17.5 | V |
| Minimum Operating Voltage After Turn-On (UC2844) | VCC(MIN) | 8.5 | 10.0 | 11.5 | V |
| Maximum Duty Cycle | DCMAX | 47 | 48 | 50 | % |
| Switching Frequency | - | - | - | Up to 500 kHz | - |
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 UC2844AQDR is suitable for a variety of applications, including:
- Off-line power supplies
- DC-to-DC converters
- Switch-mode power supplies
- High-frequency switching applications
Q & A
- What is the UC2844AQDR optimized for?
The UC2844AQDR is optimized for off-line and DC-to-DC converters.
- What is the start-up current of the UC2844AQDR?
The start-up current is less than 1mA.
- What is the maximum switching frequency of the UC2844AQDR?
The maximum switching frequency is up to 500 kHz.
- What type of output stage does the UC2844AQDR have?
The UC2844AQDR has a high-current totem-pole output stage designed to source or sink high-peak current.
- What is the operating temperature range of the UC2844AQDR?
The operating temperature range is from -40°C to 85°C.
- What is the purpose of the undervoltage lockout (UVLO) feature?
The UVLO feature ensures the device operates only within a safe voltage range, preventing damage from low supply voltages.
- How does the automatic feedforward compensation work?
The automatic feedforward compensation helps in stabilizing the control loop by compensating for changes in the input voltage.
- What is the function of the error amplifier in the UC2844AQDR?
The error amplifier is used for loop compensation and has low output resistance, enhancing the overall control loop stability.
- Can the UC2844AQDR be used in high-frequency switching applications?
Yes, the UC2844AQDR is suitable for high-frequency switching applications due to its ability to operate up to 500 kHz.
- What types of packages are available for the UC2844AQDR?
The UC2844AQDR is available in DIP-8 and SOP-8 packages.
