BA6104 five-digit LED level meter driver integrated circuit basic application circuit

BA6104 five-digit LED level meter driver integrated circuit basic application circuit

Since the input stage of BA6104 adopts the PNP composite transistor base input method, its input impedance is very high. The output stage adopts the emitter follower form. By adjusting the LED external resistor RL in the figure, the LED drive current can be changed. Connecting an external resistor to pin 7 can change Vref. When pin 7 is open, the reference voltage Vref is controlled by the IC internally, and its value is approximately 1V. If the LED display level is required to be lower than 1V, just connect a resistor RD between pin 7 and ground to reduce Vref, as shown in the figure; if the display level is required to be higher than 1V, just connect a resistor R between pin 7 and power supply VCC, then Vref will increase, and the relationship is: Vref=[Vcc 0.75R(kΩ)]]／[0.75R(kΩ) 1].