Overview
The UC3842BD1013TR is a high-performance current mode PWM (Pulse Width Modulation) controller from STMicroelectronics. It is part of the UC384xB family, designed to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. This IC is particularly suited for applications requiring precise frequency control, high current handling, and robust protection features.
Key Specifications
| Parameter | Test Conditions | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|
| Supply Voltage (Vi) | Low impedance source | - | - | 30 | V |
| Output Current (IO) | - | - | - | ±1 | A |
| Oscillator Frequency (fOSC) | Tj = 25°C, RT = 6.2k, CT = 1nF | 49 | 250 | 275 | kHz |
| Reference Voltage (VREF) | Tj = 25°C, Io = 1mA | 4.90 | 5.00 | 5.10 | V |
| Under-Voltage Lockout (UVLO) Start Threshold | - | 14.5 | 16 | 17.5 | V |
| Maximum Duty Cycle | - | 94 | 96 | 100 | % |
| Start-up Current (Ist) | Vi = 6.5V | 0.3 | 0.5 | - | mA |
| Operating Supply Current (Ii) | VPIN2 = VPIN3 = 0V | 12 | 17 | - | mA |
Key Features
- Trimmed Oscillator: Provides precise frequency control up to 500 kHz.
- Current Mode Operation: Supports current mode PWM with automatic feed-forward compensation.
- High Current Totem Pole Output: Capable of sourcing or sinking high peak currents up to 1 A.
- Under-Voltage Lockout (UVLO): Features UVLO with hysteresis to ensure reliable start-up and operation.
- Latching PWM: Provides cycle-by-cycle current limiting for enhanced protection.
- Internally Trimmed Reference: Offers a precision reference voltage with low noise and high stability.
- Low Start-up and Operating Current: Minimizes power consumption during start-up and operation.
Applications
- Off-line Power Supplies: Ideal for designing high-efficiency off-line power supplies.
- DC to DC Converters: Suitable for fixed frequency DC to DC conversion applications.
- Switch Mode Power Supplies: Used in various switch mode power supply designs requiring precise control and high reliability.
- Industrial Power Systems: Applicable in industrial power systems where robust and efficient power management is crucial.
Q & A
- What is the UC3842BD1013TR used for?
The UC3842BD1013TR is used for implementing off-line or DC to DC fixed frequency current mode control schemes in power supply applications.
- What is the maximum oscillator frequency of the UC3842BD1013TR?
The maximum oscillator frequency is up to 500 kHz.
- What is the output current capability of the UC3842BD1013TR?
The output can source or sink peak currents up to 1 A.
- What is the under-voltage lockout (UVLO) start threshold for the UC3842BD1013TR?
The UVLO start threshold is between 14.5 V and 17.5 V.
- What is the maximum duty cycle of the UC3842BD1013TR?
The maximum duty cycle is up to 100%.
- What is the start-up current of the UC3842BD1013TR?
The start-up current is less than 0.5 mA.
- How does the UC3842BD1013TR handle current limiting?
The IC features latching PWM for cycle-by-cycle current limiting.
- What is the reference voltage stability of the UC3842BD1013TR?
The reference voltage has a total output variation of 4.9 V to 5.1 V over line, load, and temperature.
- What are the typical applications of the UC3842BD1013TR?
Typical applications include off-line power supplies, DC to DC converters, and switch mode power supplies.
- What is the thermal resistance junction-ambient of the UC3842BD1013TR in SO8 package?
The thermal resistance junction-ambient is up to 150 °C/W.
