手册中BAL引脚接两个超级电容0.05F到1F,因PCB空间有限放不下这两个大电容。
请问这两个电容是必须的吗?容值是否一定要这么大?
谢谢!
Anfeng Qu:
从芯片应用的角度,当然可以不用这两个超级电容!从实际产品对Vout输出电压动态没有特别快速度要求,也可以不用。
若仍有担忧,也可以考虑留上接点,电容放到产品的其它空余空间处,然后通过导线连过来也是个方法。
The LM8850 has an internal balancing circuit that helps maintain voltage balance between the two capacitorswithin the super capacitor. The BAL pin regulates a voltage of VOUT/ 2 between the two capacitors. If onecapacitor is overcharged or less charged, the LM8850 will use the balancing circuit to correct this chargeinbalance. The balancing circuit can be turned off/on via the I2C registers (BALMODE – Control Reg01, bit 3).The balancing circuit also has the ability to stay ON even after the LM8850 is shutting down (BAL – ControlReg00, bit 4).