Overview
The UC3842BD1R2 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 power MOSFETs.
Key Specifications
| Rating | 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 | mJ |
| Current Sense, Voltage Feedback, Vref and Rt/Ct Inputs | Vin | −0.3 to + 5.5 | V |
| Error Amp Output Sink Current | IO | 10 | mA |
| Reference Output Voltage | Vref | 4.95 to 5.05 | V |
| Line Regulation (VCC = 12 V to 25 V) | Regline | −2.0 to 20 | mV |
| Load Regulation (IO = 1.0 mA to 20 mA) | Regload | −3.0 to 25 | mV |
| Operating Junction Temperature | TJ | −40 to +150 | °C |
| Storage Temperature Range | Tstg | −65 to +150 | °C |
Key Features
- Trimmed Oscillator for Precise Frequency Control: The oscillator frequency is programmable using external timing components RT and CT.
- Current Mode Operation: Supports operation up to 500 kHz.
- Automatic Feed Forward Compensation: Enhances stability and performance.
- Latching PWM for Cycle-By-Cycle Current Limiting: Ensures single pulse metering and prevents multiple pulses in a cycle.
- Internally Trimmed Reference with Undervoltage Lockout: Provides a stable reference voltage and protects against undervoltage conditions.
- High Current Totem Pole Output: Suitable for driving power MOSFETs.
- Undervoltage Lockout with Hysteresis: Protects against input and reference undervoltage conditions.
- Low Startup and Operating Current: Minimizes power consumption.
- Pb-Free and Halide-Free Device: Compliant with environmental regulations.
Applications
The UC3842BD1R2 is designed for various power conversion applications, including:
- Off-line converters
- DC-DC converters
- Step-Up and Step-Up/Step-Down converters
- Power supplies requiring high efficiency and reliability
Q & A
- What is the primary function of the UC3842BD1R2?
The UC3842BD1R2 is a high-performance fixed frequency current mode controller designed for off-line and DC-DC converter applications.
- What are the key features of the UC3842BD1R2?
Key features include a trimmed oscillator, current mode operation, automatic feed forward compensation, latching PWM, internally trimmed reference, high current totem pole output, and undervoltage lockout with hysteresis.
- What is the maximum output current of the UC3842BD1R2?
The maximum output current is 1.0 A.
- What is the operating junction temperature range of the UC3842BD1R2?
The operating junction temperature range is −40 to +150°C.
- What types of packages are available for the UC3842BD1R2?
The device is available in 8-pin dual-in-line and surface mount (SOIC-8) packages, as well as a 14-pin surface mount (SOIC-14) package.
- How is the oscillator frequency programmed in the UC3842BD1R2?
The oscillator frequency is programmed using external timing components RT and CT.
- What protective features are included in the UC3842BD1R2?
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.
- Is the UC3842BD1R2 compliant with environmental regulations?
Yes, it is a Pb-Free and Halide-Free device.
- What is the typical reference output voltage of the UC3842BD1R2?
The typical reference output voltage is 5.0 V.
- What are the common applications of the UC3842BD1R2?
Common applications include off-line converters, DC-DC converters, and power supplies requiring high efficiency and reliability.
