alinili68
Newbie level 1
Hello Tahmid, i forget to mention that i have tried it too before (connect the pin 9 to the 5V instead of 12V) but it didn't work. After read your reply and re-reading the datasheet i found this typical connection at the datasheet :
and then i changed the circuit base on your reply and the typical connection into this :
the circuit consist of 3 separate power supply :
1. vcc (5V) & gnd from the uC board
2. 7.4V Li-ion batt for the motor supply
3. 12V from the power supply
it works just fine and i able to control the motor speed with PWM (5V) that generated from my microcontroller. And when i connect the 1k resistor between gate and source of each MOSFET, the motor run strangely. The motor seems to run and stop periodically even the PWM is on the high duty cycle. when i disconnect the resistor the motor run normally.
the most strange problem that i face now is when i disconnect all 3 power supply from the circuit and try to run it again, it just do nothing. The motor won't run until change the circuit with 12V on VDD, Lin, and Hin. After i do that (run the motor for a while) i able to control the motor with 5V vdd, 5V Lin, and PWM (5V) to the Hin. i have no idea what is going on, is it from the improper capacitor value?
i think this document is related to your problem :
dt99-7-Alleviating High Side Latch on Problem at Power Up
it is an app note from IRF