Part Number: ISOW7841
I used ISOW7841 at VCC = 3.3V, VISO = 3.3V and connected 510Ω as a VISO load.
Vcc and VISO are connected to 10uF and 0.1uF respectively.
The Icc at that time is 270 mA with a pulse width of 3 us and repeats in 15 to 25 us cycles.Is this a normal current waveform?
Yes, this is expected peak current. If you would like to reduce the peak current then you can either use a series ferrite bead that limits the peak current or reduce output decoupling capacitors from "10uF + 0.1uF" to "3.3uF + 0.1uF". You can also do both of these options which should definitely reduce the input peak current. Let me know the resuojce you try these experiments. Thanks.
Regards, Koteshwar Rao
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In reply to Koteshwar Rao:
Thank you for your reply.
I would like to check the current when the output decoupling capacitors are reduced.
In addition, I am thinking of double-insulating SPI communication using two ISOW7841 as shown below. Please tell me the optimum value of the C1-C3 capacitor in this circuit.
In reply to user6246671:
The decoupling capacitors for each ISOW device should be independently provided and also placed within 2mm distance from its power supply pins, Hence, each ISOW7841 device should have 10µF + 0.1µF at VCC and 3.3µF + 0.1µF at VISO. Therefore, you would have to replace C2 with two sets of resistors (10µF + 0.1µF at VCC and 3.3µF + 0.1µF).
Let me know if you have any other questions, thank you.
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