tda5235 Infineon Technologies Corporation, tda5235 Datasheet - Page 78

• Manufacturer Part Number: tda5235
• Description: Enhanced Sensitivity Double-configuration Receiver With Digital Baseband Processing
• Manufacturer: Infineon Technologies Corporation

TDA5235
Functional Description
In default mode the Strobe signal is active high and has a delay of T
/16 relative to the
BIT
data bit and a duration of T
/2. The polarity of the Strobe signal is programmable, this
BIT
can be done via PPCFG2 register.
RXD
D
D
n
n+1
RXSTR
T
/16
T
/2
BIT
BIT
Figure 48
Timing of the Packet Oriented Transparent Payload Mode
Transparent Mode - Chip Data and Strobe (TMCDS)
The receiver’s simple plain data interface in this Transparent Mode is shown in
Figure
49. In this mode, the demodulated data signal is made directly available on the
data output pin of the data interface. Concurrently, an estimate of the chip clock is
optionally provided on the respective clock output line. Note that a sensible chip clock
can only be generated if the selected line encoding exhibits a constant chip rate. The
chip clock generation can be significantly improved by using a run-in signal of alternating
one-zero chips (maximum number of transitions within a data stream).
data
TDA5235
interface
RX data
RX chip strobe
bit
synchronizer
scheduler
Figure 49
Data interface for the Transparent Mode - Chip Data and Strobe
In the TDA5235, there is a specific digital output line for the chip clock estimate as well
as for the data output line, which delivers the encoded chip data. During inactivity of the
receiver, the line is in default mode switched to low.
The PPx pin provides the estimated chip clock, if CH_STR is selected. Further details
are given in
Chapter
2.5.3.
Data Sheet
78
V1.0, 2010-02-19