PC/104 Board Delivers 24-Bit A/D Conversion

The MPC624 PC/104 expansion board debuts as the first of its kind to offer 24-bit a/d conversion to PC/104 users. It provides two measurement options: voltage with accuracy up to 6.5 digits and direct connection to standard sensors. Mounting in a PC/104 stack, the board adds up to four channels of differential voltage readings over a software selectable input range of ±1.01 Vdc or ±10.1 Vdc with fault protection up to ±40 Vdc. The 24-bit, delta-sigma a/d converter specifies a dynamic range of 132 dB and allows all common sensors to connect directly to the board via screw terminals. For sensors requiring excitation, the board provides constant current or constant voltage through a matrix of jumpers to all channels, which are individually jumper selectable for an input impedance of 10 k?, 100 k?, or 1 G?. Ten conversion speeds with single cycle settling from 6.8 Hz to 3.5 kHz are available with an accuracy-versus-speed tradeoff. Additionally, at the lowest sampling rate, the board exhibits noise levels of 1.2 mV&subRMS; and a long-term stability of ±3 ppm. Single-unit price is $425. MICRO/SYS INC., Montrose, CA. (818) 244-4600.