Overview
The UC3842AN2 is a high-performance current mode PWM (Pulse Width Modulation) controller produced by onsemi. It is designed for off-line and DC-to-DC converter applications, offering a cost-effective solution with minimal external components. This controller is available in an 8-pin dual-in-line plastic package (PDIP) and is part of the UC3842A series, which includes other variants like the UC3843A and UC2842A/UC2843A for different voltage applications.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage | VCC | - | - | 30 | V |
| Reference Output Voltage | Vref | 4.95 | 5.0 | 5.05 | V |
| Line Regulation | Regline | -2.0 | - | 20 | mV |
| Load Regulation | Regload | -3.0 | - | 25 | mV |
| Temperature Stability | TS | -0.2 | - | - | mV/°C |
| Oscillator Frequency | fosc | 47 | 52 | - | kHz |
| Output Current Sink/Source | ISink/ISource | 2.0/-0.5 | - | 12/-1.0 | mA |
| Operating Junction Temperature | TJ | - | - | 150 | °C |
| Operating Ambient Temperature | TA | 0 | - | 70 | °C |
| Storage Temperature Range | Tstg | -65 | - | 150 | °C |
Key Features
- Trimmed Oscillator Discharge Current: For precise duty cycle control.
- Current Mode Operation: Up to 500 kHz.
- Automatic Feed Forward Compensation: Enhances stability.
- Latching PWM for Cycle-by-Cycle Current Limiting: Ensures safe operation.
- Internally Trimmed Reference with Undervoltage Lockout (UVLO): UVLO thresholds of 16 V (on) and 10 V (off) for UC3842A, and 8.5 V (on) and 7.6 V (off) for UC3843A.
- High Current Totem Pole Output: Suitable for driving power MOSFETs.
- Programmable Output Deadtime: Allows for customization of deadtime.
- Single Pulse Metering Latch: For protective features.
- Separate Power and Ground Pins for Totem Pole Output Stage (in SOIC-14 package): Improves performance and noise reduction.
Applications
The UC3842AN2 is specifically designed for off-line and DC-to-DC converter applications. It is suitable for a variety of power supply designs, including:
- Off-line converters
- DC-to-DC converters
- Switch-mode power supplies
- High-efficiency power conversion systems
Q & A
- What is the primary function of the UC3842AN2?
The UC3842AN2 is a current mode PWM controller designed for off-line and DC-to-DC converter applications.
- What are the UVLO thresholds for the UC3842A and UC3843A?
The UC3842A has UVLO thresholds of 16 V (on) and 10 V (off), while the UC3843A has thresholds of 8.5 V (on) and 7.6 V (off).
- What is the maximum operating frequency of the UC3842AN2?
The UC3842AN2 can operate up to 500 kHz.
- What type of output does the UC3842AN2 have?
The UC3842AN2 has a high current totem pole output, suitable for driving power MOSFETs.
- What are the key protective features of the UC3842AN2?
The key protective features include input and reference undervoltage lockouts, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering.
- What are the available package types for the UC3842AN2?
The UC3842AN2 is available in an 8-pin dual-in-line plastic package (PDIP) and a 14-pin plastic surface mount (SOIC-14) package.
- What is the operating ambient temperature range for the UC3842AN2?
The operating ambient temperature range is from 0°C to 70°C.
- What is the storage temperature range for the UC3842AN2?
The storage temperature range is from -65°C to 150°C.
- Does the UC3842AN2 have automatic feed forward compensation?
Yes, the UC3842AN2 includes automatic feed forward compensation to enhance stability.
- Can the UC3842AN2 operate at 100% duty cycle?
Yes, the UC3842A and UC3843A can operate within a 100% duty cycle.
