Rabbit BL2020, Руководство пользователя

Страница: 22 / 94

18 Wildcat (BL2000)
Figure 7(c). Example of Logic Gate Driving BL2000 Digital Input
The actual switching threshold is approximately 2.40 V for channels IN0–IN10. Anything
below this value is a logic 0, and anything above is a logic 1
.
The A/D converter inputs can be used as additional digital inputs using the parameters
specified for the
digIn
software function call. The default threshold for channels IN11–
IN21 is also set to 2.40 V, but may be changed by adding two lines to your program as dis-
cussed for the
digIn
software function call.
The digital inputs are each fully protected over a range of -36 V to +36 V, and can handle
short spikes of ±40 V.
Figure 8. BL2000 Digital Input Protected Range
10 nF
22 k W
27 k W
Rabbit 2000™
Microprocessor
Vcc
1
3
JP6
+40 V
+36 V
+3.3 V
–40 V
Normal Switching
Levels
Spikes
Digital Input V
oltage
Spikes
Spikes