TDA5230XT Infineon Technologies, TDA5230XT Datasheet - Page 73

• Manufacturer Part Number: TDA5230XT
• Manufacturer: Infineon Technologies

Specifications of TDA5230XT

• Operating Temperature (min): -40C
• Operating Temperature (max): 105C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 4.4mm
• Product Length (mm): 9.7mm
• Lead Free Status / Rohs Status: Compliant

Accuracy is optimized by trimming true RSSI at noise level (no input signal) to a
calculated value of -0.92 to 0.90 and at strong input signals (about -10 dBm) to +1.
It is recommended either to use RSSI with the default settings (minimum offset, minimum
gain) or to use the following trim procedure. This guarantees optimal ASK sensitivity. It
is not recommended to use trimming to increase RSSI resolution or slope.
Recommended Analog Trimming Procedure:
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See also the Recommended Digital Trimming Procedure in
Detector. If trimming is required it is only necessary to do either analog or digital
trimming, but results of the two trimming procedures are slightly different.
Usually, it is recommended to use the digital RSSI.
Recommended applications for the analog RSSI are:
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If optimal accuracy is required and to reduce thermal drift, it is recommended to read all
four RSSI signals (RSSI+, RSSI-, REF+ and REF-) within a few seconds.
Data Sheet
Download configuration file
Send 0x35 to the register LIMC1; this enables the RSSI buffer, selects RSSI-, and
sets the RSSI offset to a middle value
Measure RSSI- voltage at RSSI pin (26)
Send 0x55 to the register LIMC1, REF+ is selected
Measure REF+ voltage at RSSI pin (26)
Send 0x75 to the register LIMC1, REF- is selected
Measure REF- voltage at RSSI pin (26)
Send 0x15 to the register LIMC1, RSSI+ is selected
Measure a RSSI voltage curve at RSSI pin (26) from noise or (no input signal) to a
high signal (about -10 dBm) using a continuous wave input signal.
Normalize the curve using the formula for true RSSI earlier in this chapter
Change LIMOFFS (LIMC1, bit 0..3) until true RSSI without input signal is between -
0.92 and -0.9
Change LIMGAIN (LIMC0, bit 0..4) until true RSSI at -10 dBm is smaller but next to
+1
The new values for LIMGAIN and LIMOFFS must be added to the configuration!
Debugging and watching RF traffic
External ASK demodulation
Relative signal power measurements
69
Chapter 2.4.8.3 RSSI Peak
Functional Description
Version 4.0, 2007-06-01
TDA523x