PSB3186FV14XP Lantiq, PSB3186FV14XP Datasheet - Page 50

• Manufacturer Part Number: PSB3186FV14XP
• Manufacturer: Lantiq

Specifications of PSB3186FV14XP

• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / Rohs Status: Compliant

3.3.6.2
Synchronization problems can occur on a S-Bus that is not terminated properly.
Therefore, it is recommended to change the resistor values in the receive path. The sum
of both resistors is increased from 10 k W (1.8 + 8.2) to e.g. 34 k W (6.8 + 27) for either
receiver line. This change is possible but not necessary for a S-Bus that is terminated
properly.
Figure 25
Note: Lower or higher values than 34 k W may be used as well, however for values above
3.3.7
The S/T transmitter is shifted by two S/T bits minus 7 oscillator periods (plus analog
delay plus delay of the external circuitry) with respect to the received frame. To
compensate additional delay introduced into the receive and transmit path by the
external circuit the delay of the transmit data can be reduced by another two oscillator
periods (2 x 130 ns). Therefore PDS of the TR_CONF2 register must be programmed to
’1’. This delay compensation might be necessary in order to comply with the "total phase
deviation input to output" requirement of ITU-T recommendation I.430 which specifies a
phase deviation in the range of – 7% to + 15% of a bit period.
3.3.8
If MODE1.CFS is set to ’0’, the clocks are also provided in power down state, whereas
if CFS is set to ’1’ only the analog level detector is active in power down state. All clocks,
including the IOM-2 interface, are stopped (DD, DU are ’high’, DCL and BCL are ’low’).
Data Sheet
34 k W the additional delay must be compensated by setting TR_CONF2.PDS=1
(compensates 260 ns) so the allowed input phase delay is not violated.
S-Transceiver Synchronization
S/T Interface Delay Compensation
Level Detection Power Down
Note: Capacitors (up to 10 pF) are optional for noise reduction.
SR2
SR1
External Circuitry for Symmetrical Receivers
GND
R1
R1
50
Description of Functional Blocks
R2
R2
V
DD
1:1
21150_33
S Bus
ISAC-SX TE
PSB 3186
2003-01-30