YTD428_07 Datasheet, PDF (12/28 Pages) YAMAHA CORPORATION – IDSU ISDN DSU for Terminal Equipment

- 10 -
s T Reference Point Section
PIN DESCRIPTIONS
Pin No.
15
16
17
18
20
21
23
24
Pin Name
LI1
LICT
CX2
LI2
CX1
LO1
LO2
RX
I/O
Function
Remarks
IN S/T line input
OUT S/T line reference source output
Connecting external capacitor and resistor
- 0.1 µF capacitor and 1 MΩ resistor are to be connected across the CX2 pin
and the AVSS2 pin.
IN S/T line input
-
Connecting external capacitor
22 µF capacitor is to be connected across the CX1 pin and the AVSS2 pin.
OUT S/T line output
OUT S/T line output
-
Connecting external resistor
33 kΩ resistor is to be connected across the RX pin and the AVSS2 pin .
Note 1 When not using T ref. pt. analog interface, set these pins as bellow.
The LI1, LI2 and LICT pins are to be connected each other (short).
0.1 µF capacitor is to be connected across the LICT pin and the AVSS2 pin.
Note 2 About how to connect external capacitor and resistor, refer to “REFERENCE CIRCUIT” .
Pin No.
27
28
29
30
Pin Name
HRD
LRD
HTD
LTD
I/O
Function
OUT
NTSEL = "H": DSU transmit data (+)
NTSEL = "L": TE receive data (+)
OUT
NTSEL = "H": DSU transmit data (--)
NTSEL = "L": TE receive data (--)
IN
NTSEL = "H": DSU receive data (+)
NTSEL = "L": TE transmit data (+)
IN
NTSEL = "H": DSU receive data (--)
NTSEL = "L": TE transmit data (--)
Note
When not using TTL interface, set HTD, LTD pins as bellow.
When TDP = “H”, set HTD, LTD = “L”
When TDP = “L”, set HTD, LTD = “H”
Remarks