TDA5250 Infineon Technologies, TDA5250 Datasheet - Page 51

• Manufacturer Part Number: TDA5250
• Description: TX/RX ASK/FSK 868-870MHZ 38TSSOP
• Manufacturer: Infineon Technologies
• Type: Transceiverr

Specifications of TDA5250

• Package / Case: 38-TSSOP
• Frequency: 868MHz
• Data Rate - Maximum: 64kbps
• Modulation Or Protocol: ASK, FSK
• Applications: RKE, Remote Control Systems
• Power - Output: 9dBm
• Sensitivity: -109dBm
• Voltage - Supply: 2.1 V ~ 5.5 V
• Current - Receiving: 9mA
• Current - Transmitting: 12mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Operating Frequency: 870 MHz
• Operating Supply Voltage: 2.5 V, 3.3 V, 5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• 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: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Compliant
• Other names: SP000012956; TDA5250; TDA5250INTR; TDA5250XT; TDA5250XT

Choosing C L as large as possible results in a small pulling sensitivity. On the other hand a small C L
keeps the influence of the serial inductance and the tolerances associated to it small (see formula
[3-17]).
Start-up Time
The proportionality of L 1 and C 1 of the crystal is defined by formula [3-13]. For a crystal with a small
C 1 the start -up time will also be slower. Typically the lower the value of the crystal frequency, the
lower the C 1 .
A short conclusion regarding crystal and crystal oscillator dependencies is shown in the following
table:
Table 3-1
The crystal oscillator in the TDA5250 is a NIC (negative impedance converter) oscillator type. The
input impedance of this oscillator is a negative impedance in series to an inductance. Therefore the
load capacitance of the crystal C
capacitance C
Data Sheet
t
δ
Independent variable
δ
Start
frequency of quartz >
C
D
L
=
~
δ
where:
f
δ
−
L OSC >
S
C
´
R
C 1 >
C 0 >
C L >
L
f
Crystal and crystal oscilator dependency
v
S
L
−
as shown in formula [3-17].
1
=
R
2
ext
(
C
-R:
R
0
−
ext
+
C
:
C
1
L
)
2
is the negative impedance of the oscillator
see Figure 3-15
is the sum of all external resistances (e.g. R
other resistance that may be present in the circuit,
see Figure 3-14
Relative Tolerance Maximum Deviation
L
(specified by the crystal supplier) is transformed to the
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TDA5250 D2
t Start-up
Version 1.7
Application
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2007-02-26