nRF52832 SPI voltage level switch circuit doesn't work

[kejun]

I met a big issue when implement the voltage level switch. I used nRF52832's SPI to communicate with an ECG sensor which has 1.8V SPI. The issue is that, 3.3V signal from nRF can switch to 1.8V in ECG side (such as ECG_SPI_SCLK and ECG_SPI_DOUT), but the 1.8V signal from ECG side CAN'T change to 3.3V in nRF side (such as ECG_SPI_DIN). TXS0108 has been used several times in my design and works very well. Is there any tricky I don't know in nRF application?

Thanks

[kejun]

TXS0108 is the IC to implement 3.3V to 1.8V's voltage level shift. I found the sink current for nRF is several mA in the datesheet. It's not reasonable, since I used many MCU which's sink current is only uA level. I want to double confirm this. If it was true, TXS0108 can't drive MISO signal. But I suppose there is something I missed based on my experience.