A/D Converter Inputs - Z-World Wolf BL2600 User Manual

3.4 A/D Converter Inputs

The single A/D converter chip used in the BL2600 has a resolution of 12 bits (11 bits for the
value and one bit for the polarity). The A/D converter chip has a programmable amplifier.
Each external input has circuitry that provides scaling and filtering. All 8 external inputs
are scaled and filtered to provide the user with an input impedance of 1 MΩ and a variety
of single-ended unipolar, single-ended bipolar, and differential bipolar ranges as shown in
Table 7.
Figure 16 shows a pair of A/D converter input circuits. The resistors form an approx. 10:1
attenuator, and the capacitors filter noise pulses from the A/D converter inputs.
+ V
The A/D converter chip can only accept positive voltages. By pairing the analog inputs and
setting the reference voltage from the D/A converter [0 V for single-ended unipolar or dif-
ferential measurements, V = (voltage range) ÷ 9 for single-ended bipolar measurements],
single-ended unipolar, single-ended bipolar, differential bipolar, or current (4–20 mA on
channels 0–3 only) measurements are possible, and can be configured for each channel or
channel pair with the
Adjacent A/D converter inputs are paired to make bipolar measurements. The default
setup is to measure only voltages for the ranges listed in Table 7.
24
1 MW
AIN0
AIN1
AGND
Figure 16. Buffered A/D Converter Inputs
parameter in the
opmode
Ref. Voltage
from D/A Converter
105 kW
1 nF
105 kW
1 nF
software function call.
anaInConfig
ADC
Wolf (BL2600)