Overview
The UC2842BD1013TR, part of the UC284xB family, is a high-performance current mode PWM (Pulse Width Modulation) controller produced by STMicroelectronics. This IC is designed to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. It features a trimmed oscillator for precise frequency control, automatic feed-forward compensation, and latching PWM for cycle-by-cycle current limiting. The device is suitable for driving N-Channel MOSFETs and includes an internally trimmed reference with under-voltage lockout, ensuring reliable operation in various power supply applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage (low impedance source) | 30 | V |
| Supply Voltage (Ii < 30mA) | Self Limiting | |
| Output Current | ±1 | A |
| Output Energy (capacitive load) | 5 | µJ |
| Analog Inputs (pins 2, 3) | – 0.3 to 5.5 | V |
| Error Amplifier Output Sink Current | 10 | mA |
| Power Dissipation at Tamb ≤ 25 °C (Minidip) | 1.25 | W |
| Power Dissipation at Tamb ≤ 25 °C (SO8) | 800 | mW |
| Storage Temperature Range | – 65 to 150 | °C |
| Junction Operating Temperature | – 40 to 150 | °C |
| Lead Temperature (soldering 10s) | 300 | °C |
| Oscillator Frequency | 49 to 250 | KHz |
| Maximum Duty Cycle (UC2842B/3B) | 94 to 100 | % |
| Maximum Duty Cycle (UC2844B/5B) | 47 to 50 | % |
| Under-Voltage Lockout Start Threshold (UC2842B/4B) | 15 to 17 | V |
| Under-Voltage Lockout Start Threshold (UC2843B/5B) | 7.8 to 9.0 | V |
Key Features
- Trimmed oscillator for precise frequency control up to 500kHz.
- Current mode operation with automatic feed-forward compensation.
- Latching PWM for cycle-by-cycle current limiting.
- Internally trimmed reference with under-voltage lockout and hysteresis.
- High current totem pole output stage suitable for driving N-Channel MOSFETs.
- Low start-up and operating current (less than 0.5mA start-up current).
- Different under-voltage lockout thresholds and maximum duty cycle ranges for various members of the UC284xB family.
Applications
The UC2842BD1013TR is widely used in various power supply applications, including off-line and DC to DC converters. It is particularly suited for high-performance power management systems that require precise control over the switching frequency and current limiting. Common applications include:
- Switch-mode power supplies.
- DC to DC converters.
- Motor control systems.
- High-frequency power conversion systems.
Q & A
- What is the primary function of the UC2842BD1013TR?
The UC2842BD1013TR is a high-performance current mode PWM controller designed for implementing off-line or DC to DC fixed frequency current mode control schemes. - What is the maximum oscillator frequency of the UC2842BD1013TR?
The oscillator frequency can be programmed up to 500kHz. - What is the purpose of the under-voltage lockout feature?
The under-voltage lockout feature ensures that the device operates only when the supply voltage is within a safe range, preventing malfunction or damage. - How does the latching PWM feature work?
The latching PWM feature provides cycle-by-cycle current limiting by terminating the output switch conduction based on the current sense input. - What is the typical start-up current of the UC2842BD1013TR?
The start-up current is less than 0.5mA. - Can the UC2842BD1013TR drive N-Channel MOSFETs?
Yes, the high current totem pole output stage is designed to drive N-Channel MOSFETs. - What are the different under-voltage lockout thresholds for the UC284xB family?
The under-voltage lockout start thresholds vary between 15V to 17V for UC2842B/4B and 7.8V to 9.0V for UC2843B/5B. - What is the maximum duty cycle range for the UC2842B/3B?
The maximum duty cycle range for UC2842B/3B is 94% to 100%. - What is the maximum duty cycle range for the UC2844B/5B?
The maximum duty cycle range for UC2844B/5B is 47% to 50%. - What is the thermal resistance junction-ambient for the SO8 package?
The thermal resistance junction-ambient for the SO8 package is 150 °C/W.
