Overview
The MC34067DWG is a high-performance bipolar integrated circuit (IC) designed by ON Semiconductor for variable frequency power control in resonant mode applications. This IC is specifically tailored for off-line and DC-to-DC converter applications that utilize frequency modulated constant off-time or constant deadtime control. It is part of the MC34067/MC33067 family, which includes automotive-grade versions marked as NCV33067. The MC34067DWG is optimized for zero voltage switching (ZVS) quasi-resonant converter (QRC) applications, offering benefits such as lower switching losses, higher efficiency, lower EMI emission, and smaller size.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Power Supply Voltage | VCC | - | - | 20 | V |
| Drive Output Current (Continuous) | IO | - | - | 0.3 A | A |
| Drive Output Current (Pulsed, 0.5 μs, 25% Duty Cycle) | IO | - | - | 1.5 A | A |
| Input Voltage Range | Vin | -1.0 | - | 6.0 | V |
| Operating Junction Temperature | TJ | - | - | 150 | °C |
| Operating Ambient Temperature | TA | 0 | - | 70 | °C |
| Storage Temperature | Tstg | -55 | - | 150 | °C |
| Reference Output Voltage | Vref | 5.0 | 5.1 | 5.2 | V |
| Line Regulation | Regline | -1.0 | - | 20 | mV |
| Load Regulation | Regload | -1.0 | - | 20 | mV |
| Total Output Variation Over Line, Load, and Temperature | Vref | 4.9 | - | 5.3 | V |
Key Features
- Zero Voltage Switch Resonant Mode Operation: Designed for zero voltage switching (ZVS) quasi-resonant converter (QRC) applications, minimizing switching losses.
- Variable Frequency Oscillator: Offers a control range exceeding 1000:1, allowing for flexible frequency modulation.
- Precise Retriggerable One-Shot Timer: Ensures accurate timing and control over the power supply system.
- Temperature Compensated Reference: Provides a stable reference voltage across a wide temperature range.
- High Gain Wide Bandwidth Error Amplifier: Supports precise feedback control of the power supply system.
- Dual High Current Totem Pole Outputs: Capable of sourcing and sinking 1.5 A, ideal for driving power MOSFETs.
- Protective Features: Includes high speed fault comparator and latch, programmable soft-start circuitry, input undervoltage lockout with selectable thresholds, and reference undervoltage lockout.
- Separate Power Ground Pin: Isolates sensitive analog circuitry from large transient currents.
Applications
The MC34067DWG is specifically designed for zero voltage switching (ZVS) quasi-resonant converter (QRC) applications. It is optimized for double-ended push-pull or bridge type converters operating in continuous conduction mode. These converters are used in various power supply designs where high efficiency, low EMI emission, and minimal switching losses are critical.
Example applications include:
- DC-to-DC converters
- Off-line power supplies
- High-efficiency power conversion systems
- Resonant mode power supplies
Q & A
- What is the primary function of the MC34067DWG?
The primary function of the MC34067DWG is to provide a fixed off-time to the gates of external power MOSFETs at a repetition rate regulated by a feedback control loop in resonant mode power supply applications.
- What are the key benefits of using the MC34067DWG in power supply designs?
The key benefits include lower switching losses, higher efficiency, lower EMI emission, and smaller size.
- What types of converters is the MC34067DWG optimized for?
The MC34067DWG is optimized for double-ended push-pull or bridge type converters operating in continuous conduction mode.
- What is the maximum operating frequency of the MC34067DWG?
The MC34067DWG can operate at frequencies exceeding 1.0 MHz.
- What protective features does the MC34067DWG include?
The IC includes high speed fault comparator and latch, programmable soft-start circuitry, input undervoltage lockout with selectable thresholds, and reference undervoltage lockout.
- How does the MC34067DWG handle system startup and fault conditions?
The IC ensures that system startup and fault conditions are administered in a safe, controlled manner through its various protective and support functions.
- What is the purpose of the separate power ground pin on the MC34067DWG?
The separate power ground pin isolates the sensitive analog circuitry from large transient currents.
- What is the maximum drive output current of the MC34067DWG?
The maximum drive output current is 1.5 A for both sourcing and sinking.
- What is the operating ambient temperature range for the MC34067DWG?
The operating ambient temperature range is from 0°C to 70°C.
- Is the MC34067DWG available in automotive-grade versions?
Yes, automotive-grade versions are available and are marked as NCV33067.
