Overview
The UC2842BNG 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 ideal for driving power MOSFETs.
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. It is available in various package options, including 8-pin dual-in-line and surface mount (SOIC-8) as well as a 14-pin surface mount (SOIC-14) package.
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 | μJ |
| Current Sense, Voltage Feedback, Vref and Rt/Ct Inputs | Vin | −0.3 to + 5.5 | V |
| Reference Output Voltage | Vref | 4.95 to 5.05 | V |
| Oscillator Frequency | fOSC | 48 to 250 kHz | kHz |
| Minimum Operating Voltage After Turn-On (VCC) | VCC(min) | 9.0 to 11.5 | V |
| Power Supply Current (Startup) | ICC + IC | 0.3 to 17 | mA |
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: Provides robust current limiting capabilities.
- Internally Trimmed Reference with Undervoltage Lockout: Ensures stable reference voltage and protects against undervoltage conditions.
- High Current Totem Pole Output: Suitable for driving power MOSFETs.
- Undervoltage Lockout with Hysteresis: Prevents operation below safe voltage levels.
- Low Startup and Operating Current: Minimizes power consumption.
- Pb-Free and Halide-Free Device: Compliant with environmental regulations.
Applications
The UC2842BNG is designed for use in off-line and DC-DC converter applications. It is particularly suited for:
- Switch-mode power supplies
- DC-DC converters
- High-efficiency power conversion systems
- Industrial power supplies
- Consumer electronics power management
Q & A
- What is the primary function of the UC2842BNG?
The UC2842BNG 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 UC2842BNG oscillator?
The oscillator is trimmed for precise frequency control, programmable using external timing components RT and CT, and operates up to 500 kHz.
- What protective features does the UC2842BNG include?
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 reference output voltage of the UC2842BNG?
The typical reference output voltage is 5.0 V.
- What is the maximum output current of the UC2842BNG?
The maximum output current is 1.0 A.
- What is the minimum operating voltage after turn-on for the UC2842BNG?
The minimum operating voltage after turn-on is between 9.0 V and 11.5 V depending on the specific model.
- Is the UC2842BNG Pb-Free and Halide-Free?
Yes, the UC2842BNG is Pb-Free and Halide-Free, making it compliant with environmental regulations.
- What are the typical package options for the UC2842BNG?
The device is available in 8-pin dual-in-line and surface mount (SOIC-8) as well as a 14-pin surface mount (SOIC-14) package.
- What is the purpose of the error amplifier in the UC2842BNG?
The error amplifier provides a fully compensated output with access to the inverting input and output, featuring a high DC voltage gain and unity gain bandwidth.
- How does the UC2842BNG handle current sensing and limiting?
The device includes a current sensing comparator and supports cycle-by-cycle current limiting, ensuring robust current management.
