Overview
The UC3844BVD is a high-performance fixed frequency current mode controller produced by ON Semiconductor. It is specifically designed for off-line and DC-to-DC converter applications, offering a cost-effective solution with minimal external components. This integrated circuit features an oscillator, a temperature-compensated reference, a high-gain error amplifier, a current sensing comparator, and a high-current totem pole output ideal for driving a power MOSFET. The device includes protective features such as input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, and adjustable output deadtimes from 50% to 70%.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Manufacturer | ON Semiconductor | |
| Series | UC3844B | |
| Package | 8-pin DIP, 8-pin SOIC, 14-pin SOIC | |
| Operating Temperature | -40°C to 105°C | °C |
| Supply Voltage (Vcc) | 10 V to 36 V | V |
| Switching Frequency | Up to 500 kHz | kHz |
| Output Current | ±1 A | A |
| Reference Output Voltage | 4.9 V to 5.1 V | V |
| UVLO Thresholds | 16 V (on), 10 V (off) | V |
| Duty Cycle | Up to 48% | % |
| Output Deadtime Adjustable | 50% to 70% | % |
Key Features
- Trimmed Oscillator for Precise Frequency Control
- Oscillator Frequency Guaranteed at 250 kHz
- Current Mode Operation to 500 kHz Output Switching Frequency
- Output Deadtime Adjustable from 50% to 70%
- Automatic Feed Forward Compensation
- Latching PWM for Cycle-By-Cycle Current Limiting
- Internally Trimmed Reference with Undervoltage Lockout
- High Current Totem Pole Output
- Undervoltage Lockout with Hysteresis
- Low Startup and Operating Current
- Pb-Free Packages are Available
- Fault-Tolerant Design for High Reliability
- Low Noise and RFI Immunity
Applications
The UC3844BVD is designed for various power management applications, including:
- Off-Line Converters
- DC-to-DC Converters
- Boost, Flyback, and Isolation Capable Output Step-Up/Step-Down Converters
- Power Supplies requiring high efficiency and reliability
Q & A
- What is the primary function of the UC3844BVD?
The UC3844BVD is a high-performance fixed frequency current mode controller designed for off-line and DC-to-DC converter applications.
- What are the available package options for the UC3844BVD?
The device is available in 8-pin DIP, 8-pin SOIC, and 14-pin SOIC packages.
- What is the operating temperature range of the UC3844BVD?
The operating temperature range is -40°C to 105°C.
- What is the maximum switching frequency of the UC3844BVD?
The maximum switching frequency is up to 500 kHz.
- What are the UVLO thresholds for the UC3844BVD?
The UVLO thresholds are 16 V (on) and 10 V (off).
- Can the output deadtime be adjusted in the UC3844BVD?
Yes, the output deadtime can be adjusted from 50% to 70%.
- Does the UC3844BVD have built-in protective features?
Yes, it includes protective features such as input and reference undervoltage lockouts with hysteresis and cycle-by-cycle current limiting.
- Is the UC3844BVD suitable for high-reliability applications?
Yes, it is designed with a fault-tolerant design for high reliability.
- What is the typical reference output voltage of the UC3844BVD?
The typical reference output voltage is 5.0 V.
- Is the UC3844BVD Pb-free and RoHS compliant?
Yes, the device is Pb-free and RoHS compliant.
