Overview
The UC3845BVDR2G is a high-performance fixed frequency current mode controller produced by onsemi. It is part of the UC3844B and UC3845B series, designed for off-line and dc-to-dc converter applications. This integrated circuit offers a cost-effective solution with minimal external components, making it ideal for a variety of power management needs. The device features an oscillator, a temperature-compensated reference, a high gain error amplifier, a current sensing comparator, and a high current totem pole output suitable for driving power MOSFETs.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Oscillator Frequency | 250 kHz | |
| Output Switching Frequency | Up to 500 kHz | |
| Output Deadtime Adjustable | 50% to 70% | |
| UVLO Thresholds (On/Off) | 8.5 V / 7.6 V | V |
| Minimum Operating Voltage After Turn-On | 7.6 V | V |
| High Current Totem Pole Output | 200 mA / 200 mA (Sink/Source) | mA |
| Package Type | SOIC-14 | |
| Operating Temperature Range | -40°C to +105°C | °C |
Key Features
- Trimmed Oscillator for Precise Frequency Control
- 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 and RoHS Compliant
Applications
The UC3845BVDR2G is specifically designed for off-line and dc-to-dc converter applications. It is suitable for use in:
- Off-line converters
- Dc-to-dc converters
- Boost and flyback converters
- Power supplies requiring high efficiency and reliability
Q & A
- What is the primary function of the UC3845BVDR2G?
The UC3845BVDR2G is a high-performance fixed frequency current mode controller designed for off-line and dc-to-dc converter applications.
- What is the oscillator frequency of the UC3845BVDR2G?
The oscillator frequency is guaranteed at 250 kHz.
- What is the range of output deadtime adjustment for the UC3845BVDR2G?
The output deadtime can be adjusted from 50% to 70%.
- What are the UVLO thresholds for the UC3845BVDR2G?
The UVLO thresholds are 8.5 V (on) and 7.6 V (off).
- What is the minimum operating voltage after turn-on for the UC3845BVDR2G?
The minimum operating voltage after turn-on is 7.6 V.
- What type of package is the UC3845BVDR2G available in?
The UC3845BVDR2G is available in a SOIC-14 package.
- What is the operating temperature range for the UC3845BVDR2G?
The operating temperature range is -40°C to +105°C.
- Is the UC3845BVDR2G Pb-Free and RoHS compliant?
- What are some of the protective features of the UC3845BVDR2G?
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 typical current output of the totem pole output stage?
The high current totem pole output can sink and source up to 200 mA.
