TDA5252XT Infineon Technologies, TDA5252XT Datasheet - Page 38

• Manufacturer Part Number: TDA5252XT
• Manufacturer: Infineon Technologies

Specifications of TDA5252XT

• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 4.4mm
• Product Length (mm): 9.7mm
• Operating Supply Voltage (min): 2.1V
• Operating Supply Voltage (max): 5.5V
• Lead Free Status / Rohs Status: Compliant

Figure 3-2
The RF-signal is able to run from the RF-input-SMA-connector to the LNA-input-pin LNI via C1, C2,
C7, L3 and C9. R1 does not affect the matching circuit due to its high resistance. The other input of
the differential LNA LNIX can always be AC-grounded using a large capacitor without any loss of
performance. In this case the differential LNA can be used as a single ended LNA, which is easier
to match. The S11 of the LNA at pin LNI on the evalboard is 0.931 / -44° (equals a resistor of
1.2kOhm in parallel to a capacitor of 1.4pF) for both high and low-gain-mode of the LNA. (pin LNIX
AC-grounded) This impedance has to be matched to 50 Ohm with the parts C9, L3, C7 and C2. C1
is a DC-decoupling-capacitor. On the evalboard the most important matching components are
(shunt) L3 and (series)C7, C2. The capacitors is mainly a DC-decoupling-capacitor and may be
used for some fine tuning of the matching circuit. A good CAE tool (featuring smith-chart) may be
used for the calculation of the values of the components. However, the final values of the matching
components always have to be found on the board because of the parasitics of the board, which
highly influence the matching circuit at RF.
Data Sheet
RX-Mode
RX/TX-pin of IC)
(with jumper or
SMA-connector
grounded
50 Ohm
RF I/O
RX/TX
C2
C1
R1
C6
C7
38
C3
L3
L2
C9
C4
L1
C10
VCC
C5
RX/TX
LNI
LNIX
PA
TDA5252 G2
Version 1.1
Application
2007-02-26
RX_Mode.wmf