TDA5250XT Infineon Technologies, TDA5250XT Datasheet - Page 42

• Manufacturer Part Number: TDA5250XT
• Manufacturer: Infineon Technologies

Specifications of TDA5250XT

• 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

tolerances of components affect matching too much. This will cause problems in a tuning-free mass
production of the application. A good CAE-tool will help to see the effects of component tolerances
on the input matching more accurate by tweaking each value.
A very high selectivity can be reached by using SAW-filters at the expense of higher cost and lower
sensitivity which will be reduced by the losses of the SAW-Filter of approx. 4dB.
Image-suppression:
Due to the quite high 1
frequency of the receiver is at:
The image suppression on the evalboard is about 16dB.
LO-leakage:
The LO of the 1
The LO-leakage of the evalboard on the RF-input is about –98dBm. This is far below the ETSI-
radio-regulation-limit for LO-leakage.
3.1.3
The evalboard can be set into the TX-Mode by grounding the RX/TX-jumper on the evalboard or
programming the TDA5250 to operate in the TX-Mode. If the IC is programmed to operate in the
TX-Mode, the RX/TX-pin will act as an open drain output at a logical LOW. Then a DC-current can
flow from VCC to GND via L1, L2, D1, R1 and D2.
Now both pin-diodes are biased with a current of approx. 0.3mA@3V and have a very low
impedance for RF.
Data Sheet
f
LO
I
f
PIN
IMAGE
=
−
DIODE
f
RECEIVE
=
f
Switch in TX-Mode
SIGNAL
=
*
Vcc
st
4
3
Mixer is at:
+
=
−
2
868
2
∗
∗
st
f
3 .
V
-IF of the frontend, the image frequency is quite far away. The image
IF
MHz
FORWARD
R
=
1
868
∗
4
3
,
3 .
PIN
=
MHz
−
1157
DIODE
+
.
73
2
*
MHz
289
42
4 .
=
1447
2 .
MHz
TDA5250 D2
Version 1.7
Application
2007-02-26
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