Part Number: ISO7841
We input high signal on OUT pin, and find the signal is pulled to GND. Is it normal symptom?
Are there any internal pull down circuit in ISO7841?
In reply to Anand Reghunathan:
This can happen is ISO7841 (or ISOW7841) is used to isolate an SPI device. The isolated device (VCC2 side) only drives the isolated MISO signal when enabled by the chip select signal. Unfortunately, the ISO7841 drives the MISO signal on the VCC1 side, even if MISO on the VCC2 side is not driven by the device. This prevents other SPI devices on the VCC1 side using MISO.
This can be overcome with a three-state buffer (1G125 for example) which allows SPI devices on the VCC1 side to use MISO when the isolated device is not enabled. It would be connected like this....
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