Rabbit BL2020, User Manual

Page: 33 / 94

User’s Manual 29
Only the BL2000 and the BL2020 models are stuffed with D/A converters. The D/A con-
verters provide only a voltage output. This means that in order to maintain the maximum
accuracy of the D/A converters, only a small amount of current should be drawn from the
D/A converter output (of the order of µA).
With D/A converters installed, the user has the option of using an unbuffered A/D con-
verter input to read the output of a D/A converter or one of the two fixed voV or
Vcc. The standard BL2000 configuration is for A/D converter channels 9 and 10 to moni-
tor D/A converter channels 0 and 1 respectively.
Figure 19 shows the D/A converter outputs with buffer amplifiers, which may be used to
increase the D/A converter output voltage range to 0 V to +10 V.
Figure 19. D/A Converter Outputs
11 k
W
10 nF
DAC0
AGND
DAC1
DAC0
ADC
AIN9
1 k
W
+
–
+
–