tda5225 Infineon Technologies Corporation, tda5225 Datasheet - Page 35

• Manufacturer Part Number: tda5225
• Description: Enhanced Sensitivity Multi-channel Quad-conf Igurat Ion Receiver With Digital Slicer
• Manufacturer: Infineon Technologies Corporation

In case of a Wake-Up, the actual peak value is written in the RSSIPWU register. Even
in case no Wake-Up occurred, actual peak value is written in the RSSIPWU register at
the end of the actual configuration/channel of the Self Polling period. So if no Wake-Up
occurred, then the RSSIPWU register contains the peak value of the last
configuration/channel of the Self Polling period, even in a Multi-Configuration/Multi-
Channel setup. This functionality can be used to track RSSI during unsuccessful Wake-
Up search due to no input signal or due to blocking RSSI detection.
For further details please refer to
Chapter 2.6.2 Polling Timer
Figure 14
Recommended Digital Trimming Procedure
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Data Sheet
Download configuration file (Run Mode Slave; RSSISLOPE, RSSIOFFS set to
default, i.e. RSSISLOPE=1, RSSIOFFS=0)
Turn off AGC (AGCSTART=0) and set gain to AGCGAIN=0
Apply P
Read RSSIRX eleven times (minimum 10 ms in-between readings), use average of
last ten readings (always), store as RSSIM1
Apply P
Read RSSIRX eleven times (minimum 10 ms in-between readings), use average of
last ten readings (always), store as RSSIM2
Calculate measured RSSI slope SLOPEM=(RSSIM2-RSSIM1)/(P
Adjust
RSSISLOPE=SLOPER/SLOPEM
Adjust
RSSIOFFS=(RSSIR2-RSSIM2)+(SLOPEM-SLOPER)*P
The new values for RSSISLOPE and RSSIOFFS have to be added to the
configuration!
internal RSSIPRX =
RSSIPRX Register
internal RSSI
Data Pattern
SPI read out
RSSIPRX
Input
IN1
IN2
RSSIOFFS
RSSISLOPE
= -85 dBm RF input signal
= -65 dBm RF input signal
Peak Detector Behavior
Noise
Reset
Run-In
for
for
Unit.
required
required
Chapter 2.4.8.2 Wake-Up Generator
35
Data
value
RSSI
SPI
RSSIR2
slope
IN2
SLOPER
Functional Description
at
Noise
P
IN2
IN2
-P
Run-In
V1.0, 2010-02-19
IN1
as
as
)
TDA5225
Data
follows:
follows:
and