User`s manual

XP8900 I/O Configurations s 51
XP8900 Series Circuitry
The XP8900s D/A circuitry consists of eight 12-bit AD5320 D/A convert-
ers, U9 to U16, and two OP497G quad op-amp chips, U3 and U4. The
outputs of the D/A converters are amplified, and the analog outputs appear
on Wago connectors J1 and J2. The input comes on the PLCBus from the
program running on the controller.
Figure 7-3 illustrates the operation of the D/A conversion.
Figure 7-3. Schematic Illustration of D/A Conversion in XP8900 Series
The analog outputs do not need any special configuration. The desired
analog output voltage is set using the software drivers.
The XP8900 Series expansion boards derive +5 V digital power from the
+24 V PLCBus supply via LM7805 at U6. When operating without user-
supplied external voltage rails, the XP8900 Series D/A converters get their
+12 V analog power from the PLCBus +24 V supply via LM7812 at U7.
Charge pump NJU7662 at U17 inverts this for onboard -12 V analog
power. Precision +5 V and + 2 V reference voltages are derived from the
+12 V supply via REF195 at U2 and the voltage divider formed from R33,
R34, and R39. The n-channel FET FDV301N at Q1 is used to switch the
2V reference to 0 V during a power-on reset.
The XP8900 Series D/A converters have the capability of receiving their
+12 V or -12 V supply from an external source. This provides for greater
control of electrical noise in the analog output signals.
The XP8900 Series D/A converters may be used with 12 V
controllers only when ±12 V is supplied externally to pins 7
and 9 of Wago connector J2. Remember to set the jumpers on
headers H1, H2, and H3 as shown in Figure 7-2.
U2
VS
SLEEP
GND
OUT
REF
/2V_EN
+12IN
CPOUT
–12IN
U7
+V
IN
GND
OUT
12 V Reg
+12 V
V+C+
GND
C– VOUT
H3
CPIN
DIN
SCLK
/SYNC
VOUT
DAC
+
–
DA_EN[0–7]
DA_CLK
DA_DATA
+12 V
H1
H2
+5 V REF
R39 36 kΩ
+2 V REF
R33 30 kΩ
R34
11 kΩ
200 kΩ
200 kΩ
205 kΩ
205 kΩ
Q1
FDV301N
U17
U9–U16
-12 V REF
+12 V REF
U3 or U4
OUT[0–7]
!