TDA5251 Infineon Technologies, TDA5251 Datasheet - Page 49

• Manufacturer Part Number: TDA5251
• Description: TXRX FSK/ASK SGL LP TSSOP-38
• Manufacturer: Infineon Technologies
• Type: Transceiverr

Specifications of TDA5251

• Package / Case: 38-TSSOP
• Frequency: 315MHz
• Data Rate - Maximum: 64kbps
• Modulation Or Protocol: ASK, FSK
• Applications: RKE, Remote Control Systems
• Power - Output: 13dBm
• Sensitivity: -109dBm
• Voltage - Supply: 2.1 V ~ 5.5 V
• Current - Receiving: 9.3mA
• Current - Transmitting: 14mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Operating Frequency: 0.35 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: SP000014554; TDA5251; TDA5251INTR; TDA5251XT

Figure 3-13
With the aid of this formula it becomes obvious that the higher the serial capacitance C V is, the
higher is the influence of L OSC .
The tolerance of the internal oscillator inductivity is much higher, so the inductivity is the dominating
value for the tolerance.
FSK modulation and tuning are achieved by a variation of C
In case of small frequency deviations (up to +/- 1000 ppm), the desired load capacitances for FSK
modulation are frequency depending and can be calculated with the formula below.
Data Sheet
C
L
=
C L ±
C
1
V
−
Crystal Oscillator
ω
1
=
2
L
C L
----------------------------------------------------------------------------------------- -
OSC
C
ω:
L
C
C
C
f:
N:
∆f:
OSC
1
L
L
0
1
+ −
:
:
:
:
±
↔
C 0
----------
N f ⋅
:
∆f
C
⋅
----------
N f ⋅
V
∆f
-R
⋅
=



crystal load capacitance for nominal frequency
angular frequency
inductivity of the crystal oscillator - typ: 2.2µH with pad of board
crystal load capacitance for nominal frequency
shunt capacitance of the crystal
motional capacitance of the crystal
crystal oscillator frequency
division ratio of the PLL
peak frequency deviation
1
C
⋅
1
+



L
1
2
---------------------------------
+
+
⋅
ω
1
(
2
---------------------------------
C 0
2
TDA 5250
⋅
C
L
(
1
L
OSC
C
+
OSC
C
0
C L
1
+
C
)



L
)
49



f, C
v
.
L
C
V
2.1µH without pad
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TDA5251 F1
Version 1.1
Application
2007-02-26
QOSZ_NIC.wmf