• Resolved

TRS3232E: Output signal issue at case of Vcc=5V

Part Number: TRS3232E


Output signal has issue at Vcc=5V.
Please see below waveform.
Blue is input signal, Purple is output signal.
Do you know the reason why output waveform has ripple?

Best regards,

  • Hello Shimizu-san,

    The driver works by pulling the output voltage to the V+ rail to send a high/positive level and by pulling it to the V- rail to send a low/negative level. There is expected to be some ripple on the V+ and V- rails since they are generated based on VCC using a switching charge pump circuit. The level and frequency of ripple will be a function of the charge pump design as well as the external capacitance values and the loading on the RS-232 output. You can read more about the charge pump in this blog:


    Considering this, the waveforms you provided look normal. This should not present issues for communication since even with the ripple the signals will always exceed the high-level and low-level thresholds defined by the RS-232 standard.

    Please let me know if this is not clear or if you have any further questions.