Microchip TC4426EOA713 Dual MOSFET Driver: Features and Application Circuits
The Microchip TC4426EOA713 stands as a high-performance, dual-channel MOSFET driver designed to efficiently switch N-channel power MOSFETs and IGBTs in a wide array of applications. As a member of Microchip's extensive power management family, this driver is engineered to provide the necessary current to rapidly charge and discharge the large gate capacitances of power switches, which is critical for minimizing switching losses and improving overall system efficiency.
Key Features of the TC4426EOA713
The TC4426EOA713 is packed with features that make it a robust and reliable choice for power conversion circuits.
High Peak Output Current: It can deliver high peak output currents of up to 1.5A, enabling very fast switching speeds for the connected MOSFETs.
Dual Independent Channels: The IC incorporates two independent driver channels, offering design flexibility. They can be used to control two separate switches or configured in a parallel connection to effectively double the available output current for driving a single, very large MOSFET.
Wide Operating Voltage Range: With an operating voltage range from 4.5V to 18V, it is compatible with various logic levels and power supply rails, including standard 5V, 12V, and 15V supplies.
Fast Switching Speeds: It features very fast rise and fall times, typically in the range of 25ns, which ensures clean and efficient switching transitions.
Low Output Impedance: A low output impedance ensures strong gate drive, holding the MOSFET firmly in its on or off state and improving noise immunity.
Latch-Up Protection: The device is built with latch-up resistant construction, preventing catastrophic failure due to parasitic SCR activation.
Matched Propagation Delays: The two channels feature closely matched propagation delays, which is crucial for applications requiring precise timing between channels, such as in half-bridge configurations.
Application Circuits
The versatility of the TC4426EOA713 allows it to be deployed in numerous circuit topologies. Here are two common application circuits:
1. Driving Two Independent MOSFETs:
Each channel of the driver is connected to a separate MOSFET. The input of each channel (IN_A and IN_B) is driven by a separate signal from a PWM controller or microcontroller. The outputs (OUT_A and OUT_B) connect directly to the gates of their respective MOSFETs. A low-impedance, high-frequency bypass capacitor must be placed very close to the Vdd and GND pins of the driver to handle the high peak currents required during switching. This setup is typical in synchronous buck converters or controlling two independent motor windings.
2. Parallel Operation for Higher Current Drive:
For driving a single MOSFET with an exceptionally large gate charge (Qg), the two channels can be connected in parallel. The inputs (IN_A and IN_B) are tied together to receive a single control signal. Similarly, the outputs (OUT_A and OUT_B) are connected together to drive the single gate. This configuration effectively doubles the peak output current capability to approximately 3A, allowing for even faster switching of large power devices. Small series gate resistors (e.g., 1-5 Ω) are often used on each output before they are tied together to prevent potential oscillations and balance the current between the two internal drivers.
3. Half-Bridge Configuration:
While the TC4426 is not an inverting driver, it can be used in a half-bridge topology when the controller provides complementary logic signals. One channel drives the high-side MOSFET and the other drives the low-side MOSFET. The critical requirement here is the use of a bootstrap circuit to generate the voltage required to drive the high-side MOSFET's gate above the supply rail. A bootstrap diode and capacitor are essential components in this setup. The closely matched propagation delays of the TC4426's channels help in minimizing shoot-through current in the half-bridge.
ICGOODFIND Summary
The Microchip TC4426EOA713 is a highly versatile and robust dual MOSFET driver, prized for its high peak current output, fast switching speeds, and design flexibility. Its ability to be configured for independent, parallel, or half-bridge operation makes it an indispensable component in modern power electronics, including switch-mode power supplies (SMPS), motor control systems, Class-D amplifiers, and any application requiring precise and efficient control of power MOSFETs or IGBTs.
Keywords:
MOSFET Driver, Gate Driving, TC4426, Switching Speed, Half-Bridge
