Overview
The UC2842BDG 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, and a high-current totem pole output ideal for driving power MOSFETs. The device includes protective features such as input and reference undervoltage lockouts, cycle-by-cycle current limiting, and programmable output deadtime.
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 |
| Reference Output Voltage (IO = 1.0 mA, TJ = 25°C) | Vref | 4.95 - 5.05 | V |
| Oscillator Frequency (TJ = 25°C) | fOSC | 48 - 250 kHz | kHz |
| Output Voltage Low State (ISink = 20 mA) | VOL | 0.1 - 1.6 V | V |
| Output Voltage High State (ISource = 20 mA) | VOH | 12 - 13.5 V | V |
| Maximum Power Dissipation @ TA = 25°C (SOIC-14) | Pd | - | mW |
| Thermal Resistance, Junction-to-Air (SOIC-14) | RthJA | - | °C/W |
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.
- 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 under low voltage conditions.
- Low Startup and Operating Current: Minimizes power consumption.
- Pb-Free and Halide-Free Device: Compliant with environmental regulations.
Applications
The UC2842BDG is designed for use in off-line and DC-DC converter applications. It is particularly suitable 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 typical oscillator frequency of the UC2842BDG?
The oscillator frequency is typically guaranteed at 250 kHz, but it can be programmed using external timing components RT and CT.
- What is the maximum output current of the UC2842BDG?
The maximum output current, source or sink, is 1.0 A.
- What are the UVLO thresholds for the UC2842BDG?
The UVLO thresholds are 16 V (on) and 10 V (off) for the UC2842B series.
- What is the reference output voltage of the UC2842BDG?
The reference output voltage is typically 5.0 V, with a range of 4.95 to 5.05 V.
- What are the package options for the UC2842BDG?
The device is available in 8-pin dual-in-line, SOIC-8, and SOIC-14 packages).
- What is the thermal resistance of the SOIC-14 package?
The thermal resistance, junction-to-air, for the SOIC-14 package is specified in the datasheet, but exact values depend on the specific configuration).
- Does the UC2842BDG have built-in current limiting?
Yes, it features cycle-by-cycle current limiting and a latch for single pulse metering).
- Is the UC2842BDG Pb-Free and Halide-Free?
Yes, the device is Pb-Free and Halide-Free, making it compliant with environmental regulations).
- What is the typical DC voltage gain of the error amplifier?
The error amplifier has a typical DC voltage gain of 90 dB).
- What is the maximum power dissipation of the UC2842BDG at TA = 25°C?
The maximum power dissipation at TA = 25°C is specified in the datasheet, but it depends on the package and configuration).
