///　　　　The basic specs of the ADS7870 are:

///　　　　- Fast SPI interface (up to 20MHz)

///　　　　- 12-bit results

///　　　　- 8 single-ended or 4 differential input channels

///　　　　- Programmable gain stage (1,2,4,5,8,10,16,20x gains)

///　　　　- Software or hardware triggered conversion

///　　　　- 4-bit auxiliary digital I/O lines (controlled via serial interface)

///　　　　- Up to 50KHz conversion rate

///　　　　- External reference or internal 2.5V, 2.048V, 1.15V reference

///　　　　- NOTE: use pin-compatible ADS7871 for 14-bit results