Advance Information
MH88437-P
15
13
RS
11
LOOP
VR+
LCD
TIP
ILOOP
16K
3
4
5
28
1
VR-
NB1
NB2
DUT
VX
21
22
23
2
VLOOP5
VLOOP4
VLOOP3
VLOOP2
VLOOP1
27
10
RING
82K
24
25
VBIAS
10uF
+
LC RV AGND VCC ZA
9
7
6
16
8
1K
4.7K
5V
= Ground (Earth)
5V
Figure 6 - Test Circuit 1
-V
10H 500Ω
15
13
11
100uF
+
RS
LOOP
VR+
LCD
TIP
3
4
5
I=20mA
28
1
VR-
NB1
DUT
VX
16K
Vs
21
22
23
2
VLOOP5
NB2
Impedance = Zin
VLOOP4
VLOOP3
VLOOP2
VLOOP1
100uF
+
27
10
RING
82K
24
25
10H 500Ω
VBIAS
10uF
+
LC RV AGND VCC ZA
7
9
6
16
8
1K
4.7K
5V
5V
= Ground (Earth)
Gain = 20 * Log (VX / Vs)
Figure 7 - Test Circuit 2
11