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TRS3122E: Unused pin and schematic check

Part Number: TRS3122E

Hi Sirs,

As title,

Could you help check schematic first and give us some suggestion on unused pin, ( I saw Unused driver inputs should be connected to GND or VCC). How about Rout/Dout/Rin unused pin?

20180124-TRS3122ERGER.output.pdf

Thanks!!

  • Shu-Cheng,
    Actually internally Din is pulled up to VL by 2MOhm resistor. It's OK you leave them open or externally connected to gnd/Vcc. Rin has 5kOhm pull down resistor due to RS232 standard. You'd better keep as is. Rout and Dout will be biased or become high impedance with no power. There is no risk leaving them open.
    Talking about schematic, I would recommend to use 16V rating for the caps (C4020, C4021, C4023, C4024, C4025), since the supply voltage could be tripled by the charge pump circuitry.
    Please let me know if you have other questions.
    Regards,
    Hao