Four dmos tubes are integrated inside the motor drive chip to form a standard H-type drive axle. The grid control voltage is provided to the two switch tubes of the upper bridge arm through the charging pump circuit, which is operated by an operating frequency of about 300kHz.
A second charging pump circuit can be formed by connecting an external capacitor in pins 1 and 11. The larger the external capacitor, the faster the capacitor charging speed input to the gate of the switch tube, the shorter the voltage rise time, and the higher the operating frequency.
Pin 2 and 10 are connected to the DC motor armature, and the direction of current should be from the lead step to pin 10 when turning forward; The direction of the current when reversed should be from pin 10 to pin 2. The current detection output pin 8 can be connected to a resistance to the ground, through which the overcurrent is output.
The overcurrent threshold set by the internal protection circuit is 10A. When the overcurrent threshold is exceeded, the output will be automatically blocked and the output will be automatically restored periodically. If the overcurrent lasts for a long time, the overheat protection will shut down the entire output.
The overheating signal can also be output through pin 9, which has an output signal when the junction temperature reaches 145 degrees.
The driver chip adopts standard TTL logic level signal control, with two enable control terminals, which allow or prohibit the device to work without being affected by the input signal, and a logic power input terminal, which makes the internal logic circuit part work under low voltage; Can be connected to the external detection resistance, the change of the feedback to the control circuit.
Driver chip principle:
Four dmos tubes are integrated inside the motor drive chip to form a standard H-type drive axle. The grid control voltage is provided to the two switch tubes of the upper bridge arm through the charging pump circuit, which is operated by an operating frequency of about 300kHz.