Overview
The MC34067PG, produced by onsemi, is a high-performance zero voltage switch resonant mode controller. This integrated circuit is designed for off-line and dc-to-dc converter applications, utilizing frequency modulated constant off-time or constant deadtime control. It is particularly suited 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
| Parameter | Value | Unit |
|---|---|---|
| Power Supply Voltage (VCC) | 20 | V |
| Drive Output Current (Continuous) | 0.3 | A |
| Drive Output Current (Pulsed, 0.5 μs, 25% Duty Cycle) | 1.5 | A |
| Reference Output Voltage | 5.0 - 5.2 | V |
| Maximum Switching Frequency | 2200 | kHz |
| Operating Junction Temperature | -40 to +150 | °C |
| Operating Ambient Temperature | 0 to +70 (MC34067), -40 to +85 (MC33067, NCV33067) | °C |
| Storage Temperature | -55 to +150 | °C |
| ESD Capability (HBM Model) | 2.0 kV |
Key Features
- Zero Voltage Switch Resonant Mode Operation
- Variable Frequency Oscillator with a control range exceeding 1000:1
- Precise retriggerable one-shot timer
- Temperature compensated reference
- High gain wide bandwidth error amplifier
- Steering flip-flop and dual high current totem pole outputs for driving power MOSFETs
- Protective features including high speed fault comparator and latch, programmable soft-start circuitry, input undervoltage lockout with selectable thresholds, and reference undervoltage lockout
- Separate power ground pin to isolate sensitive analog circuitry from large transient currents
Applications
The MC34067PG 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 half-bridge converters, such as a 75 W output from a 48 V source, and other resonant mode power supply configurations.
Q & A
- What is the primary function of the MC34067PG?
The MC34067PG is a high-performance zero voltage switch resonant mode controller designed to provide a fixed off-time to the gates of external power MOSFETs at a repetition rate regulated by a feedback control loop.
- What are the key benefits of using the MC34067PG in power supply designs?
The key benefits include lower switching losses, higher efficiency, lower EMI emission, and smaller size.
- What is the maximum switching frequency of the MC34067PG?
The maximum switching frequency is 2200 kHz.
- What type of converters is the MC34067PG optimized for?
The MC34067PG is optimized for double-ended push-pull or bridge type converters operating in continuous conduction mode.
- What protective features does the MC34067PG include?
The protective features include a high speed fault comparator and latch, programmable soft-start circuitry, input undervoltage lockout with selectable thresholds, and reference undervoltage lockout.
- How does the MC34067PG handle fault conditions?
The MC34067PG includes a fault latch that disables the oscillator and the one-shot timer when a fault condition occurs. The fault latch can be reset during startup or by momentarily pulling the Enable/UVLO Adjust pin low.
- What is the purpose of the separate power ground pin on the MC34067PG?
The separate power ground pin isolates the sensitive analog circuitry from large transient currents.
- What is the operating temperature range for the MC34067PG?
The operating ambient temperature range is 0 to +70°C for the MC34067 and -40 to +85°C for the MC33067 and NCV33067.
- What is the storage temperature range for the MC34067PG?
The storage temperature range is -55 to +150°C.
- What is the ESD capability of the MC34067PG?
The ESD capability is 2.0 kV according to the HBM model.
