Cirrus Logic CS61880 - Manual (Page 50)

CS61880
50 DS450PP3
18. APPLICATIONS
Figure 16. Internal RX/TX Impedance Matching
+
RGND
+3.3V
RV+
T1 1:2
REF
CS61880
One Channel
T R I N G
T T I P
TRANSMIT
LINE
T2 1:1.15
R T I P
R R I N G
R1
R2
13.3k
Ω
GND
CBLSEL
TV+
VCCIO
+3.3V
+
TGND
+
GNDIO
NC
75
Ω
Cable
120
Ω
Cable
+3.3V
68
µ
F
0.1
µ
F 0.1
µ
F
0 .1
µ
F
0 .1
µ
F
RECEIVE
LINE
Note 2
Note 1 Note 1
Notes:1) Required Capacitor between each TV+, RV+, VCCIO and TGND, RGND, GNDIO respec-
tively.
2) Common decoupling capacitor for all TVCC and TGND pins.
Component E1 75
Ω
Coaxial Cable E1 120
Ω
Twisted Pair Cable
R1 (
Ω
) 15 15
R2 (
Ω
) 15 15