I have a dual channel digital pot using an SPI interface (MCP4261):


http://ww1.microchip.com/downloads/en/DeviceDoc/22059b.pdf

I'm confused about this SPI interface based on the following reasons:

On page 41 (section 6.1.5), it states that "the CS signal must transition from the inactive state (VIH) to an active state (VIL or VIHH)."

On page 11, it demonstrates this by showning CS going from VIH (a voltage between VIHH and VIL) to VIHH.

Furthermore, on page 9, it states that min schmitt trigger high input threshold (VIH) is .45Vdd (at Vdd = 5V), while VIL is <= .2Vdd.

So does this mean I have to keep CS between 1V and 2.25V (for Vdd=5V) for it to be "inactive"? This is counter to most SPI interfaces I've used (CS is inactive when high, active when low).

Any help or insight is appreciated!

Thanks,
Dave