Overview
The UC3842BVD1G is a high-performance fixed frequency current mode controller produced by onsemi. This device is part of the UC3842B and UC3843B series, which are specifically designed for off-line and DC-to-DC converter applications. The UC3842BVD1G offers a cost-effective solution with minimal external components, making it an ideal choice for a wide range of power management needs.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Reference Output Voltage | Vref | 4.95 | 5.0 | 5.05 | V |
| Oscillator Frequency | fOSC | - | 250 kHz | - | kHz |
| Maximum Duty Cycle | DC(max) | - | 94% | - | % |
| Startup Threshold (VCC) | Vth | 16 | - | 17 | V |
| Minimum Operating Voltage After Turn-On (VCC) | VCC(min) | 9.0 | - | 11 | V |
| Output Current, Source or Sink | IO | - | - | 1.0 A | A |
| Power Dissipation @ TA = 25°C | - | - | - | 751 mW | mW |
| Thermal Resistance, Junction-to-Air | - | - | - | 100°C/W | °C/W |
Key Features
- Trimmed Oscillator for Precise Frequency Control: The oscillator frequency is programmable using external timing components RT and CT, ensuring precise duty cycle control.
- Current Mode Operation: Supports operation up to 500 kHz, making it suitable for high-frequency applications.
- Automatic Feed Forward Compensation: Enhances stability and performance of the converter.
- Latching PWM for Cycle-by-Cycle Current Limiting: Ensures reliable current limiting and prevents overcurrent conditions.
- Internally Trimmed Reference with Undervoltage Lockout: Provides a stable reference voltage and protects against undervoltage conditions.
- High Current Totem Pole Output: Capable of driving power MOSFETs with high current output.
- Low Startup and Operating Current: Minimizes power consumption during startup and operation.
- Pb-Free and Halide-Free Device: Compliant with environmental regulations.
Applications
- Off-Line Converters: Suitable for designing off-line power supplies due to its high voltage handling capabilities.
- DC-to-DC Converters: Ideal for DC-to-DC conversion applications requiring high performance and reliability.
- Power Management Systems: Used in various power management systems where precise control over output voltage and current is necessary.
Q & A
- What is the primary function of the UC3842BVD1G?
The UC3842BVD1G is a high-performance fixed frequency current mode controller designed for off-line and DC-to-DC converter applications.
- What is the typical oscillator frequency of the UC3842BVD1G?
The oscillator frequency is typically 250 kHz.
- How is the oscillator frequency programmed in the UC3842BVD1G?
The oscillator frequency is programmed using external timing components RT and CT.
- What is the maximum output current of the UC3842BVD1G?
The maximum output current is 1.0 A.
- Does the UC3842BVD1G have undervoltage lockout protection?
Yes, it includes undervoltage lockout protection with hysteresis.
- What is the thermal resistance of the UC3842BVD1G in the SOIC-14 package?
The thermal resistance is typically 100°C/W.
- Is the UC3842BVD1G Pb-Free and Halide-Free?
Yes, it is Pb-Free and Halide-Free, complying with environmental regulations.
- What are the typical operating temperature ranges for the UC3842BVD1G?
The operating temperature ranges are from 0°C to 70°C for UC3842B and from -40°C to 105°C for UC3842BV.
- How does the current sense comparator work in the UC3842BVD1G?
The current sense comparator monitors the inductor current and compares it to a level derived from the error amplifier output, controlling the peak inductor current on a cycle-by-cycle basis.
- Can the UC3842BVD1G be synchronized with an external clock signal?
Yes, it can be synchronized with an external clock signal by applying the clock to the RT/CT pin.
