5 PICOSCALE HARDWARE
5.3.1 Differential Digital Interface DDI
The Differential Digital Interface (DDI) provides two differential digital
signals, which can be used
for di
ff
erent digital protocols, e.g. AquadB and Serial Data. With the Breakout-Box the signals are
distributed to three DSub 15 connectors, one per channel. The pin assignment is shown in
fi
gure
5.4 and speci
fi
ed in table 5.1.
8
7
6
5
4
3
2
1
15
14
13
12
11
10
9
Figure 5.4: Pin assignment of the DSub 15 connector.
Table 5.1
–
Pin assignment of DSub 15 AquadB connectors
Signal
Direction
AquadB
serial data
1
Out
A positive
CLOCK positive
2
Out
B positive
DATA positive
3 - 7
-
not connected
-
8
-
System Ground
System Ground
9
Out
A negative
CLOCK negative
10
Out
B negative
DATA negative
11 - 15
-
not connected
-
Shielding
-
System Ground
System Ground
The output levels of the speci
fi
c DD
I
pins are illustrated in
fi
gure 5.5. Main performance parame-
ters are listed in 5.2.
1
3.5
V
t
AquadB.X_P
AquadB.X_N
Figure 5.5: Output level of the speci
fi
c pins of the AquadB connector, where the
X
is to be replaced
by the individual channel number and quadrature (A or B). The indices
P
and
N
denote
the positive and negative part of a di
ff
erential AquadB pair.
36
PicoScale User Manual
