Overview
The MC34067DWR2 is a high-performance resonant mode controller designed by onsemi. This integrated circuit is specifically tailored for off-line and DC-to-DC converter applications, utilizing frequency modulated constant off-time or constant deadtime control. The device features a variable frequency oscillator, a precise retriggerable one-shot timer, a temperature-compensated reference, a high-gain wide-bandwidth error amplifier, a steering flip-flop, and dual high-current totem pole outputs ideal for driving power MOSFETs.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Reference Output Voltage (IO = 0 mA, TJ = 25°C) | Vref | 5.0 | 5.1 | 5.2 | V |
| Line Regulation (VCC = 10 V to 18 V) | Regline | -1.0 | - | 20 | mV |
| Load Regulation (IO = 0 mA to 10 mA) | Regload | -1.0 | - | 20 | mV |
| Total Output Variation Over Line, Load, and Temperature | Vref | 4.9 | - | 5.3 | V |
| Output Short Circuit Current (0°C to 70°C) | IO | 30 | 25 | 100 | mA |
| Reference Undervoltage Lockout Threshold | Vth | 3.8 | 4.3 | 4.8 | V |
| Error Amplifier Input Offset Voltage (VCM = 1.5 V) | VIO | -1.0 | - | 10 | mV |
| Error Amplifier Input Bias Current (VCM = 1.5 V) | IIB | -0.2 | - | 1.0 | μA |
| Error Amplifier Open Loop Voltage Gain (VCM = 1.5 V, VO = 2.0 V) | AVOL | 70 | 100 | - | dB |
| Gain Bandwidth Product (f = 100 kHz) | GBW | 3.0 | 2.7 | 5.0 | MHz |
| Input Common Mode Rejection Ratio (VCM = 1.5 V to 5.0 V) | CMR | 70 | 95 | - | dB |
| Power Supply Rejection Ratio (VCC = 10 V to 18 V, f = 120 Hz) | PSR | 80 | 100 | - | dB |
| Output Voltage Swing | - | - | - | 9.5 to 10.3 | V |
| Output Voltage Rise Time (CL = 1.0 nF) | tr | 20 | - | 50 | ns |
| Output Voltage Fall Time (CL = 1.0 nF) | tf | 15 | - | 50 | ns |
Key Features
- Zero Voltage Switch Resonant Mode Operation: Optimized for minimal switching loss.
- Variable Frequency Oscillator: Control range exceeding 1000:1.
- Precise Retriggerable One-Shot Timer: Ensures accurate timing.
- Temperature Compensated Reference: Provides stable reference voltage.
- High-Gain Wide-Bandwidth Error Amplifier: Enhances control loop stability.
- Dual High-Current Totem Pole Outputs: Ideal for driving power MOSFETs.
- Protective Features: Includes high-speed fault comparator, programmable soft-start circuitry, input undervoltage lockout, and reference undervoltage lockout.
Applications
The MC34067DWR2 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 commonly used in DC-to-DC power supplies where high efficiency and minimal switching losses are critical.
- DC-to-DC Converters: Particularly suited for half-bridge and full-bridge configurations.
- Off-Line Power Supplies: Used in applications requiring high efficiency and reliability.
- Resonant Mode Controllers: Ideal for applications that benefit from zero voltage switching to reduce losses.
Q & A
- What is the primary application of the MC34067DWR2?
The MC34067DWR2 is primarily used in zero voltage switching (ZVS) quasi-resonant converter (QRC) applications, particularly in DC-to-DC converters and off-line power supplies.
- What are the key features of the MC34067DWR2?
Key features include a variable frequency oscillator, a precise retriggerable one-shot timer, a temperature-compensated reference, a high-gain wide-bandwidth error amplifier, and dual high-current totem pole outputs.
- What protective features does the MC34067DWR2 have?
The device includes a high-speed fault comparator, programmable soft-start circuitry, input undervoltage lockout, and reference undervoltage lockout.
- What is the operating temperature range of the MC34067DWR2?
The operating temperature range is from 0°C to 70°C, with storage temperature ranging from -55°C to 150°C.
- What is the typical output short circuit current of the MC34067DWR2?
The typical output short circuit current is 25 mA, with a maximum of 100 mA.
- How does the MC34067DWR2 reduce switching losses?
The device reduces switching losses through zero voltage switching (ZVS) resonant mode operation, ensuring that the voltage across the power transistor is zero before turn-on.
- What type of packages is the MC34067DWR2 available in?
The device is available in dual-in-line and surface mount packages.
- What is the gain bandwidth product of the error amplifier?
The gain bandwidth product is typically 2.7 MHz to 5.0 MHz.
- What is the input common mode rejection ratio?
The input common mode rejection ratio is typically 95 dB.
- How does the MC34067DWR2 ensure stable operation?
The device ensures stable operation through its temperature-compensated reference and high-gain wide-bandwidth error amplifier.
