Overview
The UC3842BVD1R2 is a high-performance fixed frequency current mode controller produced by onsemi. It is part of the UC3842B and UC3843B series, which are specifically designed for off-line and DC-DC converter applications. These controllers offer a cost-effective solution with minimal external components, making them ideal for a variety of power management applications.
The device 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. This output is well-suited for driving power MOSFETs. Additionally, the controller 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 | Symbol | Value | 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) | W | 5.0 | μJ |
| Current Sense, Voltage Feedback, Vref and Rt/Ct Inputs | Vin | −0.3 to +5.5 | V |
| Compensation Voltage | Vcomp | −0.3 to +7.2 | V |
| Output Voltage | Vo | −0.3 to VCC or VC + 0.3 | V |
| Error Amp Output Sink Current | IO | 10 | mA |
| Output Voltage Low State (ISink = 20 mA) | VOL | 0.8 - 1.1 | V |
| Output Voltage High State (ISource = 20 mA) | VOH | 5.0 - 6.2 | V |
| Output Voltage Rise Time (CL = 1.0 nF, TJ = 25°C) | tr | 50 - 150 | ns |
| Output Voltage Fall Time (CL = 1.0 nF, TJ = 25°C) | tf | 50 - 150 | ns |
Key Features
- Trimmed oscillator for precise duty cycle control
- Temperature-compensated reference
- High-gain error amplifier with a typical DC voltage gain of 90 dB and a unity gain bandwidth of 1.0 MHz
- Current sensing comparator
- High-current totem pole output for driving power MOSFETs
- Input and reference undervoltage lockouts with hysteresis
- Cycle-by-cycle current limiting
- Programmable output deadtime
- Latch for single pulse metering
- Available in 8-pin dual-in-line and surface mount (SOIC-8 and SOIC-14) packages
Applications
- Off-line power supplies
- DC-DC converters
- Switch-mode power supplies
- Power management systems requiring high performance and reliability
Q & A
- What is the UC3842BVD1R2 used for?
The UC3842BVD1R2 is used in off-line and DC-DC converter applications, offering a cost-effective solution with minimal external components.
- What are the key features of the UC3842BVD1R2?
The key features include a trimmed oscillator, temperature-compensated reference, high-gain error amplifier, current sensing comparator, and a high-current totem pole output.
- What are the maximum ratings for the UC3842BVD1R2?
The maximum ratings include bias and driver voltages up to 30V, total power supply and zener current up to 30mA, and output current up to 1A.
- What is the output voltage range of the UC3842BVD1R2?
The output voltage range is from −0.3V to VCC or VC + 0.3V.
- What are the protective features of the UC3842BVD1R2?
The protective features include input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering.
- In what packages is the UC3842BVD1R2 available?
The UC3842BVD1R2 is available in 8-pin dual-in-line and surface mount (SOIC-8 and SOIC-14) packages.
- What is the typical DC voltage gain of the error amplifier?
The typical DC voltage gain of the error amplifier is 90 dB.
- What is the unity gain bandwidth of the error amplifier?
The unity gain bandwidth of the error amplifier is 1.0 MHz.
- How is the oscillator frequency programmed in the UC3842BVD1R2?
The oscillator frequency is programmed by the values selected for the timing components RT and CT.
- What is the purpose of the current sensing comparator?
The current sensing comparator is used to monitor and control the current in the power converter circuit.
