Overview
The UC3844BD1R2G is a high-performance fixed frequency current mode PWM controller produced by onsemi. This integrated circuit is specifically designed for off-line and DC-to-DC converter applications, offering a cost-effective solution with minimal external components. It features an oscillator, a temperature-compensated reference, a high gain error amplifier, a current sensing comparator, and a high current totem pole output stage ideal for driving power MOSFETs.
The device includes protective features such as input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, and a latch for single pulse metering. It also allows for adjustable output deadtimes from 50% to 70%.
Key Specifications
| Characteristic | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Oscillator Frequency | - | 250 | - | kHz |
| Output Switching Frequency | - | - | 500 | kHz |
| UVLO Thresholds (UC3844B) | 10 | - | 16 | V |
| UVLO Thresholds (UC3845B) | 7.6 | - | 8.5 | V |
| Output Current - Sink | - | - | 200 | mA |
| Output Current - Source | - | - | 200 | mA |
| Power Supply Voltage Range | 14 | - | 36 | V |
| Package Type | - | - | SOIC-8 | - |
Key Features
- Trimmed Oscillator for Precise Frequency Control
- Current Mode Operation up 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 Available
Applications
The UC3844BD1R2G is designed for use in off-line and DC-to-DC converter applications. It is particularly suitable for:
- Switch Mode Power Supplies
- DC-to-DC Converters
- Step-Up and Step-Down Converters
- High Efficiency Power Conversion Systems
Q & A
- What is the primary function of the UC3844BD1R2G?
The UC3844BD1R2G is a high-performance fixed frequency current mode PWM controller designed for off-line and DC-to-DC converter applications.
- What is the typical oscillator frequency of the UC3844BD1R2G?
The typical oscillator frequency is 250 kHz.
- What are the UVLO thresholds for the UC3844B?
The UVLO thresholds for the UC3844B are 16 V (on) and 10 V (off).
- What is the maximum output switching frequency of the UC3844BD1R2G?
The maximum output switching frequency is up to 500 kHz.
- What protective features does the UC3844BD1R2G include?
The device includes input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, and a latch for single pulse metering.
- What is the power supply voltage range for the UC3844BD1R2G?
The power supply voltage range is from 14 V to 36 V.
- What type of package is the UC3844BD1R2G available in?
The UC3844BD1R2G is available in an 8-pin SOIC package.
- Does the UC3844BD1R2G support Pb-free packaging?
- What is the typical output current sink and source capability of the UC3844BD1R2G?
The typical output current sink and source capability is up to 200 mA.
- What applications is the UC3844BD1R2G suited for?
The UC3844BD1R2G is suited for switch mode power supplies, DC-to-DC converters, step-up and step-down converters, and high efficiency power conversion systems.
