Overview
The UC2825BDWG4 from Texas Instruments is an enhanced high-speed PWM (Pulse Width Modulation) controller, designed to improve upon the standard UC3823 and UC3825 families. This component is part of the UC2825 series, which offers significant performance enhancements and additional features. It is compatible with both voltage-mode and current-mode control methods, making it versatile for various power conversion applications. The UC2825BDWG4 operates at switching frequencies up to 1 MHz and features high-current dual totem pole outputs, making it suitable for high-performance power supply designs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VC, VCC) | 22 | V | ||
| Output Current (DC), OUTA, OUTB | 0.5 | A | ||
| Output Current (Pulse), OUTA, OUTB | 2.2 | A | ||
| Propagation Delay to Output | 50 | ns | ||
| Startup Supply Current | 100 | 300 | μA | |
| UVLO Start Threshold Voltage | 8.4 | 9.2 | 9.6 | V |
| UVLO Stop Threshold Voltage | 9 | 10 | V | |
| Maximum Duty Cycle | 85% | |||
| Operating Temperature Range | -40 | 85 | °C |
Key Features
- Compatible with voltage-mode or current-mode control methods
- Practical operation at switching frequencies up to 1 MHz
- 50-ns propagation delay to output
- High-current dual totem pole outputs (2-A peak)
- Trimmed oscillator discharge current for accurate dead time control
- Low 100-μA startup current, ideal for off-line applications
- Pulse-by-pulse current limiting comparator and latched overcurrent comparator with full cycle restart
- Leading edge blanking for noise rejection
- Soft-start and fault management features
- Dual alternating outputs (UC2825A and UC2825B)
Applications
The UC2825BDWG4 is suitable for a variety of high-performance power supply applications, including:
- Switch-mode power supplies
- DC-DC converters
- AC-DC converters
- High-frequency power conversion systems
- Off-line power supplies requiring low startup current
Q & A
- What is the maximum switching frequency of the UC2825BDWG4?
The UC2825BDWG4 can operate at switching frequencies up to 1 MHz.
- What is the peak output current capability of the UC2825BDWG4?
The UC2825BDWG4 has high-current dual totem pole outputs capable of 2-A peak currents.
- What is the startup supply current of the UC2825BDWG4?
The startup supply current is typically 100 μA.
- Does the UC2825BDWG4 support both voltage-mode and current-mode control?
- What is the purpose of the leading edge blanking feature?
The leading edge blanking feature helps in rejecting noise inherent with switched mode power conversion.
- How does the soft-start feature work in the UC2825BDWG4?
The soft-start is programmed by a capacitor on the SS pin, and during power up, the SS pin is discharged, allowing the error amplifier output to follow until closed loop regulation takes over.
- What happens when an overcurrent condition is detected?
When an overcurrent condition is detected, the fault latch is set, and the output pins are driven low. The soft-start capacitor is then discharged by a 250-μA current sink.
- What is the operating temperature range of the UC2825BDWG4?
The operating temperature range is -40°C to 85°C.
- What is the UVLO start threshold voltage for the UC2825BDWG4?
The UVLO start threshold voltage is between 8.4 V and 9.6 V.
- What type of packaging is available for the UC2825BDWG4?
The UC2825BDWG4 is available in SOIC-16 packaging.
