101-0506 Rabbit Semiconductor, 101-0506 Datasheet - Page 103

• Manufacturer Part Number: 101-0506
• Description: CARD CPU SR9160 128K SRAM SMRTST
• Manufacturer: Rabbit Semiconductor

Specifications of 101-0506

• Accessory Type: Smart Star CPU Card
• For Use With/related Products: SR9160
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Figure 39 shows the complete pinout for the user interface on header J1. Note that pin 1 is
indicated by a small arrow on the ribbon cable connector.
Figure 39. D/A Converter Card User Interface Pinout
The D/A Converter Card has eight analog output channels,
, and is also
D/A_OUT[0–7]
equipped with a remote sensing capability through sensing inputs
for the
D/A_SEN[0–7]
voltage-amplifier versions of the D/A Converter Card (models SR9400 and SR9410).
These sensing inputs compensate for the voltage drop across the wire leads of low-impedance
loads to provide a more precise output across the load.
Let’s look at Figure 40 to see how this happens. Assume the load is 500 Ω. If the imped-
ance of the wire used to connect the load to the output terminal on the D/A Converter Card
is 5 Ω, there will be a voltage drop of about 5 Ω/500 Ω = 1% across the wire. The voltage
across the load will then be 1% less, which is about 40 counts for the SR9400. By connect-
ing
D/A_SEN
as shown in Figure 40, the output driver will be able to sense the voltage
drop across the wire and provide a more accurate voltage output across the load. If the
load impedance is much greater than the impedance of the wire leads, simply leave the
sensing inputs open.
D/A_SEN
W
W
W
W
W
W
Figure 40. D/A Converter Output for Low-Impedance Loads
User’s Manual
103