Instruction Manual

CS61884
DS485F3 51
18. APPLICATIONS
Figure 17. Internal RX/TX Impedance Matching
+
RGND
+3.3V
RV+
T1 1:2
REF
CS61884
One Channel
TRING
TTIP
TRANSMIT
LINE
T2 1:2
RTIP
RRING
R1
R2
13.3k Ω
GND
CBLSEL
TV+
VCCIO
+3.3V
+
TGND
+
GNDIO
NC
100 Ω
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
T1/J1 100Ω
Twisted Pair
Cable
E1 75Ω
Coaxial
Cable
E1 120Ω
Twisted Pair
Cable
R1 (Ω) 15 15 15
R2 (Ω) 15 15 15