P1 is a five-pin XH connector that is used to apply the chips’ supply and control signals to the board. C2, C8, D1, and D10 are selected according to the datasheet and the application requirements. Internal reverse Schottky diodes have been embedded in the MOSFETs however, using these external Schottky diodes reduces the stress on the internal diodes as well. The 1N4148 diode discharges the gate’s capacitor.ĭ4, D5, D6, and D7 3 are used to suppress the DC motor’s reverse current spikes. Don’t forget that a MOSFET introduces a capacitance on its gate pin. R1 and D2, R2 and D3, R3 and D8, and R4 and D9 have been used to damp down the ringing and parasitics that might be introduced by the inductors and capacitors at the on/off times of the MOSFETs. As it is clear, the supply of the chip and load (motor) does not need to be identical however, both supplies share a common ground.įigure 2: Wiring diagram of the IR2104 MOSFET driver chipĬ1, C3, C4, C5, C6, C7, and C9 have been used to reduce the noise. Figure 2 shows the basic wiring diagram of the chip. The good news about the IR2104 is that this chip is compatible with both 3.3-V and 5-V logic levels. The floating channel can be used to drive an N-channel power MOSFET or IGBT in the high-side configuration, which operates from 10 to 600 V.”
The output drivers feature a high-pulse-current buffer stage designed for minimum driver cross-conduction. The logic input is compatible with standard CMOS or LSTTL output, down to 3.3-V logic. Proprietary HVIC and latch-immune CMOS technologies enable ruggedized monolithic construction. According to the IR2104 datasheet: “The IR2104(S) are high-voltage, high-speed power MOSFET and IGBT drivers with dependent high- and low-side referenced output channels.
I’ve selected two IR2104 2 to drive the MOSFETs. The low thermal resistance and low package cost of the TO-220 contribute to its wide acceptance throughout the industry.” The TO-220 package is universally preferred for all commercial-industrial applications at power dissipation levels to approximately 50 W. This benefit, combined with the fast switching speed and ruggedized device design that HEXFET power MOSFETs are well known for, provides the designer with an extremely efficient and reliable device for use in a wide variety of applications. According to the IRF3205 datasheet: “Advanced HEXFET power MOSFETs from International Rectifier utilize advanced processing techniques to achieve extremely low on-resistance per silicon area. This MOSFET offers nice characteristics that are essential for this application, very low R DS(on) resistance, and high current-handling capability. I’ve selected 4 IR3205 1 to do the switching. Figure 1: Schematic diagram of the H-bridge DC motor driver