Overview
The UC3842BVD1R2G is a high-performance fixed frequency current mode controller produced by onsemi. It is specifically designed for off-line and DC-DC converter applications, offering a cost-effective solution with minimal external components. This integrated circuit features a trimmed oscillator for precise duty cycle control, a temperature-compensated reference, a high-gain error amplifier, a current sensing comparator, and a high current totem pole output suitable for driving a power MOSFET. The device includes protective features such as input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Bias and Driver Voltages (VCC, VC) | - | - | 30 | V |
| Total Power Supply and Zener Current (ICC + IZ) | - | - | 30 | mA |
| Output Current, Source or Sink (IO) | - | - | 1.0 | A |
| Output Energy (Capacitive Load per Cycle) | - | - | 5.0 | μJ |
| Reference Output Voltage (Vref) | 4.95 | 5.0 | 5.05 | V |
| Line Regulation (VCC = 12 V to 25 V) | -2.0 | - | 20 | mV |
| Load Regulation (IO = 1.0 mA to 20 mA) | -3.0 | - | 25 | mV |
| Temperature Stability | -0.2 | - | - | mV/°C |
| Oscillator Frequency | - | - | 250 | kHz |
| UVLO Startup Threshold | 16 | - | - | V |
| UVLO Turn-Off Threshold | 10 | - | - | V |
Key Features
- Trimmed Oscillator for Precise Frequency Control
- Oscillator Frequency Guaranteed at 250 kHz
- Current Mode Operation up to 500 kHz
- 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 UC3842BVD1R2G is designed for off-line and DC-DC converter applications. It is particularly suitable for:
- Off-line power supplies
- DC-DC converters, including flyback, forward, and boost converters
- High-performance power management systems requiring precise control and protection features
Q & A
- What is the primary function of the UC3842BVD1R2G?
The UC3842BVD1R2G is a high-performance fixed frequency current mode controller designed for off-line and DC-DC converter applications.
- What are the key protective features of the UC3842BVD1R2G?
The device includes input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering.
- What is the typical oscillator frequency of the UC3842BVD1R2G?
The oscillator frequency is guaranteed at 250 kHz.
- What is the maximum output current of the UC3842BVD1R2G?
The maximum output current is 1.0 A.
- What are the UVLO thresholds for the UC3842BVD1R2G?
The UVLO startup threshold is 16 V, and the turn-off threshold is 10 V.
- What types of packages are available for the UC3842BVD1R2G?
The device is available in 8-pin dual-in-line, SO-8, and 14-pin SO-14 packages.
- What is the purpose of the trimmed oscillator in the UC3842BVD1R2G?
The trimmed oscillator provides precise duty cycle control and is temperature-compensated to minimize frequency variations.
- How does the current sensing comparator work in the UC3842BVD1R2G?
The current sensing 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.
- What is the significance of the high current totem pole output in the UC3842BVD1R2G?
The high current totem pole output is ideally suited for driving a power MOSFET, ensuring efficient and reliable operation.
- Is the UC3842BVD1R2G available in Pb-free packages?
