HFC-4S Cologne Chip AG, HFC-4S Datasheet - Page 154

• Manufacturer Part Number: HFC-4S
• Description: Isdn HDLC Fifo Controller With 8 (4) Integrated S/t Interfaces
• Manufacturer: Cologne Chip AG

HFC-4S
HFC-8S
5.5 External circuitries
5.5.1 External receive circuitry
The standard external receive circuitry for TE and NT mode is shown in Figure5.6.
The HFC-4S / 8S has four / eight S/T interfaces. If a S/T is not used, the level adjustment pin
ADJ_LEV0 . . . ADJ_LEV7 must be left open. The S/T receive input pins R_A0 . . . R_A7, LEV_A0 . . . LEV_A7,
LEV_B0 . . . LEV_B7 and R_B0 . . . R_B7 should be tied to ground if their second function (GPI) is
not used as well.
5.5.2 External transmit circuitry
The standard external transmit circuitry for TE and NT mode is shown in Figure5.7.
If a S/T interface is not used, the two transmit pins T_A0 . . . T_A7 and T_B0 . . . T_B7 must be left
open if their second function (GPIO) is not used as well.
The signal level of the transmit circuitry has to be adjusted by VDD_ST (pins 181, 164, 147, 129).
The exact voltage of VDD_ST depends on the used transformer and circuitry dimensioning. For the
standard circuitry in Figure 5.7 it is about 2.8 V.
Figure 5.9 shows a voltage regulation circuitry for VDD_ST voltage generation. The PWM0 pin is
used for fine tuning the voltage by software. Alternatively the regulator circuitry can be fixed to a
suitable voltage.
154 of 273
S/T module part number
transformers:
S
¼
-modules:
ST5069
PT5135
ST5201
ST5202
543 76 009 00
503 740 010 0 (SMD)
Table 5.4: S/T module part numbers and manufacturers
S/T interface
Data Sheet
Manufacturer
Valor Electronics, Inc.
Asia
North America
Europe
Vogt electronic AG
Germany
Phone:
Fax:
URL:
Phone:
Fax:
Phone:
Fax:
Phone:
Fax:
URL:
+49 8591/ 17-0
+49 8591/ 17-240
http://www.vogt-electronic.com
(continued from previous page)
[phone]
[phone]
+1 800 31VALOR
[phone]
[phone]
[phone]
http://www.valorinc.com
March 2003 (rev. A)
Cologne
Chip