Introduction
LY3306 is a fully integrated motor drive control IC incorporating a lithium battery charge management module, motor drive module, freewheeling diode, push-button gear control, and protection module, with a standby current of only 5uA. The charging current is 0.6A; the red LED illuminates during charging, the green LED illuminates when fully charged, the green LED illuminates during discharge, and the green LED flashes to indicate low battery. The IC uses duty cycle control for 3-gear output, with gear switching via a single button press in the sequence: 50% - 75% - 100% - Off. It supports trickle, constant current, and constant voltage charging, and can charge a 0V battery. When the battery voltage falls below 2.8V, the IC enters trickle charge mode at 0.12× the constant current charge rate; once the voltage exceeds 2.8V, it transitions to constant current charging; as the battery voltage approaches 4.2V, the charging current gradually decreases until it falls to 0.12× the constant current charge rate, at which point charging terminates. After the battery is fully charged, if the 5V input remains present, the IC monitors the battery voltage and restarts charging when the voltage drops below the recharge threshold of 3.95V, preventing unnecessary repeated charge cycles to extend battery life. The IC has built-in thermal protection: during charging, if the internal temperature exceeds 120°C, the charging current is automatically reduced to stabilize the temperature; during motor drive operation, if the internal temperature reaches 150°C, the output is shut down and re-enabled once the temperature drops to 120°C. The IC continuously monitors the VM pin current; when the sustained current rises to a typical value of 2.6A, the output is shut down for protection, and a button press is required to resume operation. During discharge, when the battery voltage falls below 3.2V, the green LED flashes at 0.5Hz as a warning until the output is shut down.
