Overview
The UCC28083DR is a BiCMOS pulse width modulation (PWM) controller from Texas Instruments, designed for dc-to-dc or off-line fixed-frequency current-mode switching power supplies. It is part of the UCC38083/4/5/6 family and is specifically configured for push-pull topology. The device features dual output stages that switch at half the oscillator frequency, with a dead time between the two outputs typically limited to 110 ns, ensuring each output’s duty cycle is less than 50%.
Key Specifications
| Parameter | Value | Units |
|---|---|---|
| Package | SOIC (D) | - |
| Pins | 8 | - |
| Operating Temperature Range | -40°C to 85°C | °C |
| Start-Up Current | 120 µA (typical) | µA |
| Run Current | 1.5 mA (typical) | mA |
| Oscillator Frequency | 50 kHz to 1 MHz | kHz to MHz |
| Output Current Capability | 1-A Sink, 0.5-A Source | A |
| Undervoltage Lockout (UVLO) | 12.5 V / 8.3 V (turn on/off thresholds) | V |
| Soft-Start Interval Time | 3.5 ms (typical) | ms |
Key Features
- Programmable Slope Compensation
- Internal Soft-Start on the UCC38083/4
- Cycle-by-Cycle Current Limiting
- Low Start-Up Current and Typical Run Current
- Single External Component Oscillator Programmable from 50 kHz to 1 MHz
- High-Current Totem-Pole Dual Output Stage Drives Push-Pull Configuration
- Current Sense Discharge Transistor to Improve Dynamic Response
- Internally Trimmed Bandgap Reference
- Undervoltage Lockout with Hysteresis
Applications
- High-Efficiency Switch-Mode Power Supplies
- Telecom dc-to-dc Converters
- Point-of-Load or Point-of-Use Power Modules
- Low-Cost Push-Pull and Half-Bridge Applications
Q & A
- What is the primary function of the UCC28083DR?
The UCC28083DR is a BiCMOS PWM controller designed for dc-to-dc or off-line fixed-frequency current-mode switching power supplies.
- What is the operating temperature range of the UCC28083DR?
The operating temperature range is -40°C to 85°C.
- What are the typical start-up and run currents of the UCC28083DR?
The typical start-up current is 120 µA, and the typical run current is 1.5 mA.
- What is the programmable frequency range of the oscillator?
The oscillator frequency can be programmed from 50 kHz to 1 MHz.
- What is the output current capability of the UCC28083DR?
The device has a 1-A sink and 0.5-A source capability.
- What are the undervoltage lockout (UVLO) thresholds for the UCC28083DR?
The UVLO thresholds are 12.5 V / 8.3 V for turn on/off.
- What is the typical soft-start interval time for the UCC28083DR?
The typical soft-start interval time is 3.5 ms.
- What are some key applications of the UCC28083DR?
Key applications include high-efficiency switch-mode power supplies, telecom dc-to-dc converters, point-of-load or point-of-use power modules, and low-cost push-pull and half-bridge applications.
- What is the purpose of the programmable slope compensation in the UCC28083DR?
The programmable slope compensation helps in stabilizing the current-mode control loop and preventing subharmonic oscillations.
- How does the current sense discharge transistor improve the dynamic response of the UCC28083DR?
The current sense discharge transistor discharges any filter capacitance on the CS pin during each cycle, minimizing filter capacitor values and current sense delay.
