Microchip TC4432CPA 6-A MOSFET Driver: Datasheet, Pinout, and Application Circuit Guide

Power MOSFETs are essential components in modern electronics, controlling high currents and voltages in applications from motor drives to switch-mode power supplies. However, they cannot be driven directly by low-power signals from microcontrollers or logic circuits. This is where a dedicated MOSFET driver like the Microchip TC4432CPA becomes critical. This article provides a comprehensive overview of this powerful driver IC, covering its key specifications, pinout, and a typical application circuit.

Datasheet Overview and Key Features

The TC4432 is a member of Microchip's family of inverting MOSFET drivers. The "CPA" suffix denotes its commercial grade temperature range and its 8-pin PDIP package. It is designed to source and sink high peak current pulses of up to 6 Amps, making it capable of swiftly charging and discharging the large gate capacitances of power MOSFETs and IGBTs. This high-speed switching is crucial for minimizing transition times and reducing power losses.

Key specifications from the datasheet include:

High Peak Output Current: 6A (source and sink).

Supply Voltage Range: 4.5V to 18V, offering flexibility to drive a wide range of MOSFETs.

Logic Input Compatibility: The input is compatible with both TTL and CMOS logic levels (as low as 2.0V for a high signal), allowing for easy interfacing with microcontrollers.

Inverting Logic: The output state is the logical inverse of the input signal.

Robust Design: Features internal protection circuitry, including shoot-through protection and latch-up immunity.

TC4432CPA Pinout Configuration

Understanding the pinout is the first step to successful implementation. The TC4432CPA comes in an 8-pin PDIP package.

1. VDD (Pin 1): This is the positive supply voltage pin. A bypass capacitor must be placed as close as possible to this pin and ground.

2. Input A (Pin 2): The control input for the driver. Applying a logic-high signal here will result in a logic-low output at the corresponding OUT pin.

3. GND (Pin 3): System ground.

4. OUT A (Pin 4): The high-current output that connects directly to the gate of the MOSFET.

5. OUT B (Pin 5): High-current output for a second channel (Note: The TC4432 is a dual driver, but the TC4432 is a single driver. This pin is not connected (N/C) in the TC4432 package).

6. GND (Pin 6): System ground.

7. Input B (Pin 7): Input for a second channel (N/C for TC4432).

8. VDD (Pin 8): Positive supply voltage pin.

Note: For the single-channel TC4432, pins 5 and 7 are not internally connected and should be left floating.

Application Circuit Guide

A typical application circuit for driving an N-channel MOSFET is straightforward but requires careful attention to component selection and layout.

Components Required:

Microcontroller or logic signal source

TC4432CPA MOSFET Driver

N-Channel Power MOSFET (e.g., IRFZ44N)

Load (e.g., Motor, Lamp, Solenoid)

Bypass Capacitor: A 0.1µF to 10µF ceramic capacitor placed directly between VDD (Pin 1/8) and GND (Pin 3/6). This is critical for stability as it provides the high peak current required by the driver.

Gate Resistor (R_G): A small resistor (typically between 5Ω to 100Ω) in series with the MOSFET gate. This resistor helps dampen ringing and overshoot caused by parasitic inductances and the MOSFET's gate capacitance.

Circuit Operation:

1. The microcontroller sends a logic-high (e.g., 5V) signal to the INPUT pin (Pin 2) of the TC4432.

2. Due to its inverting architecture, the driver's OUTPUT (Pin 4) immediately switches to GND (0V), pulling the gate of the MOSFET down and turning it OFF.

3. When the microcontroller signal goes LOW (0V), the driver responds by switching its OUTPUT to VDD. This applies the full supply voltage (e.g., 12V) to the MOSFET's gate, rapidly turning it ON.

This simple circuit allows a low-power 5V microcontroller to effortlessly control a high-side load switched by a MOSFET that may be handling dozens of amps and high voltages.

ICGOOFind: The TC4432CPA is a robust and reliable workhorse for power electronics design. Its high 6A drive strength, wide operating voltage, and logical inversion make it an ideal choice for applications requiring fast switching speeds and minimal power loss, such as in motor control, power supplies, and pulse transformers. Always remember to use a sufficient bypass capacitor and a gate resistor to ensure stable and oscillation-free operation.

Keywords:

1. MOSFET Driver

2. Gate Driving

3. TC4432CPA

4. High-Current Switch

5. Inverting Driver