SA60 and LMD18245 drive DC motor circuit

SA60 driving DC motor circuit

Figure 4 is a typical wiring diagram of SA60 driving a DC motor. In this diagram, the chip is connected in analog input mode. A capacitor CT is connected between the digital input terminal (pin 2) and the analog ground. By changing its size, the frequency of the PWM carrier can be adjusted between 22 and 250kHz.

Although the continuous current output index of LDM18245 is less than one-third of that of SA60, it is flexible and convenient in terms of control mode. Different connection modes can be used to realize different control modes of the motor and obtain different control performances. Figure 5 is an example of driving a DC motor with a bipolar output mode. The fixed chopping time is 1.1 RC; the current sensing resistor RW

is calculated by the reference formula: UREF is the reference voltage of the D/A conversion circuit, D is the input voltage value of the D/A conversion circuit, and IS is the maximum setting value of the motor current. Unlike SA60, there is no PWM circuit in the LMD18245 chip. If you want to control the speed and direction of the motor through the PWM duty cycle, you need an external controller. The connection method is shown in the figure.