Overview
The MC34025DW, produced by ON Semiconductor, is a high-speed, fixed-frequency, double-ended pulse width modulator (PWM) controller. This integrated circuit is optimized for high-frequency operation and is specifically designed for off-line and DC-to-DC converter applications. It offers a cost-effective solution with minimal external components, making it an ideal choice for designers seeking efficient and reliable power management solutions.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Power Supply Voltage | VCC | - | - | 30 | V |
| Output Driver Supply Voltage | VC | - | - | 25 | V |
| Output Current, Source or Sink (DC) | IO | - | - | 0.5 A | A |
| Output Current, Source or Sink (Pulsed 0.5 μs) | IO | - | - | 2.0 A | A |
| Input and Reference Undervoltage Lockout (VCC) | - | 9.2 V | - | 8.4 V | V |
| Input and Reference Undervoltage Lockout (Vref) | - | 4.2 V | - | 3.6 V | V |
| Operating Junction Temperature | TJ | - | - | +150°C | °C |
| Operating Ambient Temperature | TA | -40°C | - | +105°C | °C |
| Reference Output Voltage (IO = 1.0 mA, TJ = +25°C) | Vref | 5.05 V | 5.1 V | 5.15 V | V |
Key Features
- High-speed, fixed-frequency operation
- Dual high current totem pole outputs for direct drive of power MOSFETs
- Wide bandwidth error amplifier
- Fully-latched logic with double pulse suppression
- Latching PWM for cycle-by-cycle current limiting
- 50 ns propagation delay to outputs
- Temperature compensated reference (5.1 V bandgap reference)
- Input and reference undervoltage lockouts with hysteresis
- Soft-start capability and hiccup mode recovery for output short circuits
- Separate pins for VC and Power Ground to reduce switching transient noise
Applications
The MC34025DW is specifically designed for off-line and DC-to-DC converter applications. It is suitable for use in:
- Switch-mode power supplies
- DC-DC converters
- High-frequency power management systems
- Power MOSFET drivers
Q & A
- What is the primary function of the MC34025DW?
The MC34025DW is a high-speed, fixed-frequency, double-ended pulse width modulator (PWM) controller designed for off-line and DC-to-DC converter applications.
- What is the maximum power supply voltage for the MC34025DW?
The maximum power supply voltage (VCC) is 30 V.
- What is the output current capability of the MC34025DW?
The output current capability is up to ±2.0 A peak drive current.
- What protective features are included in the MC34025DW?
The IC includes input and reference undervoltage lockouts, cycle-by-cycle current limiting, and a latch for single pulse metering.
- How is the oscillator frequency programmed in the MC34025DW?
The oscillator frequency is programmed by the values selected for the timing components RT and CT.
- What is the typical rise and fall time of the output drivers?
The typical rise and fall time of the output drivers is 30 ns driving a 1.0 nF load.
- What is the purpose of the separate VC supply input?
The separate VC supply input allows the designer to tailor the drive voltage independent of VCC and reduces switching transient noise.
- What is the reference output voltage of the MC34025DW?
The reference output voltage is 5.1 V with an initial accuracy of ±1.0% at 25°C.
- How does the MC34025DW handle output short circuits?
The IC features a hiccup mode recovery for output short circuits, which discharges the Soft-Start capacitor when a current limit is exceeded.
- What is the operating junction temperature range of the MC34025DW?
The operating junction temperature range is from -40°C to +105°C.
