Overview
The UC3842BVDR2G 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.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage | VCC | - | - | 30 | V |
| Output Current | IO | - | - | ±1 | A |
| Analog Inputs (Pin 2, 3) | V(ANA) | -0.3 | - | 6.3 | V |
| Error Amp Output Sink Current | ISINK (E.A) | - | - | 10 | mA |
| Reference Output Voltage | VREF | 4.90 | 5.00 | 5.10 | V |
| Oscillation Frequency | f | 47 | 52 | 57 | kHz |
| Current Sense Input Voltage Gain | AV | 2.85 | 3.00 | 3.15 | V/V |
| Maximum Current Sense Input Threshold | Vth | 0.9 | 1.00 | 1.10 | V |
| Output Voltage Low State (ISink = 20 mA) | VOL | - | - | 0.4 | V |
| Output Voltage High State (ISource = 20 mA) | VOH | 13 | - | 13.5 | V |
| Storage Temperature Range | TSTG | -65 | - | +150 | °C |
Key Features
- Trimmed Oscillator for Precise Frequency Control: The oscillator frequency is programmable using the timing components RT and CT, ensuring precise duty cycle control.
- Current Mode Operation: The device operates in current mode up to 500 kHz, providing cycle-by-cycle current limiting and peak inductor current control.
- High Gain Error Amplifier: Features a high-gain error amplifier for accurate voltage feedback and control.
- Current Sensing Comparator: Includes a current sensing comparator to monitor and control the peak inductor current.
- High Current Totem Pole Output: Capable of driving power MOSFETs with high current output.
- Undervoltage Lockout with Hysteresis: Provides UVLO thresholds with hysteresis to ensure stable operation and prevent false triggering.
- Low Startup and Operating Current: Designed for low startup and operating currents, making it energy-efficient.
- Pb-Free and Halide-Free: The device is lead-free and halide-free, adhering to environmental standards).
Applications
The UC3842BVDR2G is specifically designed for off-line and DC-DC converter applications. It is suitable for a variety of power supply designs, including:
- Switch-Mode Power Supplies: Ideal for designing efficient switch-mode power supplies with minimal external components.
- DC-DC Converters: Used in DC-DC converter applications requiring precise duty cycle control and high current output).
- Power Management Systems: Can be integrated into power management systems requiring high performance and reliability).
Q & A
- What is the primary function of the UC3842BVDR2G?
The UC3842BVDR2G is a high-performance, fixed-frequency current mode controller designed for off-line and DC-DC converter applications.
- What are the UVLO thresholds for the UC3842BVDR2G?
The UC3842BVDR2G has UVLO thresholds of 16 V (on) and 10 V (off)).
- What is the maximum output current of the UC3842BVDR2G?
The maximum output current is ±1 A).
- What is the typical oscillation frequency of the UC3842BVDR2G?
The typical oscillation frequency is 52 kHz, programmable using RT and CT components).
- What are the key features of the error amplifier in the UC3842BVDR2G?
The error amplifier features high gain, low input bias current, and high unity gain bandwidth).
- How does the current sensing comparator work in the UC3842BVDR2G?
The current sensing comparator monitors the peak inductor current and compares it to a level derived from the error amplifier output, ensuring cycle-by-cycle current limiting).
- What are the storage temperature range and operating temperature range for the UC3842BVDR2G?
The storage temperature range is -65°C to +150°C, and the operating temperature range varies by model but includes up to +105°C for some versions).
- Is the UC3842BVDR2G Pb-free and halide-free?
- What types of packages are available for the UC3842BVDR2G?
The device is available in 8-pin dual-in-line and surface mount (SOIC-8) packages, as well as a 14-pin plastic surface mount (SOIC-14) package).
- How does the undervoltage lockout with hysteresis work in the UC3842BVDR2G?
The undervoltage lockout with hysteresis prevents the device from operating below a certain voltage threshold, ensuring stable operation and preventing false triggering).
