Overview
The MC33368DR2, produced by onsemi, is an active power factor controller designed to function as a boost preconverter in off-line power supply applications. This device is optimized for low power, high density power supplies, minimizing board area, component count, and power dissipation. The MC33368 features a narrow body SOIC package, providing a small footprint, and integrates high voltage startup, saving approximately 0.7 W of power compared to resistor bootstrapped circuits.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Power Supply Voltage (Transient) | VCC | - | - | 20 | V |
| Maximum Power Dissipation @ TA = 70°C | PD | - | - | 450 | mW |
| Thermal Resistance, Junction-to-Air | RJA | - | - | 178 | °C/W |
| Operating Junction Temperature | TJ | - | - | 150 | °C |
| Operating Ambient Temperature | TA | -25 | - | 125 | °C |
| Storage Temperature Range | Tstg | -55 | - | 150 | °C |
| Input Bias Current (VFB = 5.0 V) | IIB | - | 0 | 1.0 | μA |
| Input Offset Voltage (VComp = 3.0 V) | VIO | - | - | 50 | mV |
| Transconductance (VComp = 3.0 V) | gm | 30 | 51 | 80 | μmho |
Key Features
- Lossless Off-Line Startup
- Output Overvoltage Comparator
- Leading Edge Blanking (LEB) for Noise Immunity
- Watchdog Timer to Initiate Switching
- Restart Delay Timer
- Zero Current Detector for Critical Conduction Operation
- Transconductance Error Amplifier
- Current Sensing Comparator
- 5.0 V Reference
- Undervoltage Lockout (UVLO) Circuit
- CMOS Driver for Driving MOSFETs
- Programmable Output Switching Frequency Clamp
- Cycle-by-Cycle Current Limiting
Applications
The MC33368DR2 is designed for use in off-line power supply applications, particularly in scenarios requiring high power factor correction. It is suitable for low power, high density power supplies where minimizing board area and component count is crucial. Typical applications include:
- Switch Mode Power Supplies
- Power Factor Correction (PFC) Circuits
- Boost Preconverters
- High Efficiency Power Supplies
Q & A
- What is the primary function of the MC33368DR2?
The MC33368DR2 functions as an active power factor controller and boost preconverter in off-line power supply applications.
- What are the key benefits of the high voltage startup feature?
The high voltage startup feature saves approximately 0.7 W of power compared to resistor bootstrapped circuits.
- What is the purpose of the watchdog timer?
The watchdog timer initiates output switching to ensure proper operation.
- What protection features does the MC33368DR2 include?
The device includes an output overvoltage comparator, restart delay timer, cycle-by-cycle current limiting, and undervoltage lockout (UVLO) circuit.
- What is the operating ambient temperature range for the MC33368DR2?
The operating ambient temperature range is from -25°C to +125°C.
- What is the maximum power dissipation at TA = 70°C?
The maximum power dissipation at TA = 70°C is 450 mW.
- What is the thermal resistance, junction-to-air for the SOIC-16 package?
The thermal resistance, junction-to-air is 178°C/W.
- What is the input bias current when VFB = 5.0 V?
The input bias current is typically 0 μA and maximum 1.0 μA.
- What is the transconductance of the error amplifier when VComp = 3.0 V?
The transconductance is between 30 μmho and 80 μmho.
- What are the typical applications for the MC33368DR2?
Typical applications include switch mode power supplies, power factor correction (PFC) circuits, boost preconverters, and high efficiency power supplies.
