Overview
The UC3844BVD1G is a high-performance fixed frequency current mode 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, making it ideal for driving power MOSFETs. The device is available in various package options, including 8-pin dual-in-line and surface mount (SO-8 and SO-14) packages, with the SO-14 package having separate power and ground pins for the totem pole output stage.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Reference Output Voltage | Vref | 4.95 | 5.0 | 5.05 | V |
| Oscillator Frequency | fosc | - | 250 kHz | - | kHz |
| Output Switching Frequency | fsw | - | - | 500 kHz | kHz |
| UVLO Turn-On Threshold | VUVLO(on) | 16 V | - | - | V |
| UVLO Turn-Off Threshold | VUVLO(off) | 10 V | - | - | V |
| Typical Quiescent Current | Iq | - | - | - | mA |
| Maximum Duty Cycle | D(max) | - | - | 50% | % |
| Output Voltage Swing High State | VOH | - | - | 6.2 V | V |
| Output Voltage Swing Low State | VOL | - | - | 1.1 V | V |
| Maximum Operating Supply Voltage | VCC(max) | - | - | 30 V | V |
| Minimum Operating Supply Voltage | VCC(min) | 10 V | - | - | V |
| Operating Temperature Range | Tj | -40°C | - | 125°C | °C |
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 and RoHS Compliant
Applications
The UC3844BVD1G is designed for off-line and dc-to-dc converter applications. It is particularly useful in power supply designs where high efficiency and reliability are critical. Some common applications include:
- Off-line power supplies
- Dc-to-dc converters
- Switch-mode power supplies
- High-efficiency power conversion systems
Q & A
- What is the primary function of the UC3844BVD1G?
The UC3844BVD1G 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 UC3844BVD1G?
The oscillator frequency is guaranteed at 250 kHz.
- What are the UVLO thresholds for the UC3844BVD1G?
The UVLO thresholds are 16 V (on) and 10 V (off).
- What is the maximum output switching frequency of the UC3844BVD1G?
The maximum output switching frequency is 500 kHz.
- Does the UC3844BVD1G have protective features?
Yes, it includes input and reference undervoltage lockouts, cycle-by-cycle current limiting, and a latch for single pulse metering.
- What are the package options available for the UC3844BVD1G?
The device is available in 8-pin dual-in-line and surface mount (SO-8 and SO-14) packages.
- Is the UC3844BVD1G Pb-Free and RoHS compliant?
Yes, the UC3844BVD1G is Pb-Free and RoHS compliant.
- What is the operating temperature range of the UC3844BVD1G?
The operating temperature range is from -40°C to 125°C.
- Can the output deadtime be adjusted in the UC3844BVD1G?
Yes, the output deadtime can be adjusted from 50% to 70%.
- Does the UC3844BVD1G have automatic feed forward compensation?
Yes, it includes automatic feed forward compensation.
