TDA5251 Infineon Technologies, TDA5251 Datasheet - Page 61

• 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 3-22
3.6
The data slicer is an analog-to-digital converter. It is necessary to generate a threshold value for the
negative comparator input (data slicer). The TDA5251 offers an RC integrator and a peak detector
which can be selected via logic. Independent of the choice, the peak detector outputs are always
active.
3.6.1
Table 3-12
Necessary external component (Pin14): C
This integrator generates the mean value of the data filter output. For a stable threshold value, the
cut-off frequency has to be lower than the lowest signal frequency. The cutoff frequency results from
the internal resistance R=100k Ω and the external capacitor C
Cut-off frequency:
Component calculation: (rule of thumb)
T
Data Sheet
L
D15
Bit
– longest period of no signal change
Data Slicer - Slicing Level
RC Integrator
Sub Address 00H: CONFIG
Function
SLICER
Typ. RSSI Level (Eval Board) @3V
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
-120
C
f
-110
SLC
cut
−
≥
off
-100
100
=
3
0= LP, 1= Peak Detector
2
⋅
-90
T
k
π
L
Ω
⋅
100
-80
SLC
Description
RF /dBm
1
k
-70
Ω
61
⋅
C
-60
SLC
-50
<
Min
high gain
low gain
-40
{
f
SLC
-30
Signal
on Pin14.
-20
}
ADC
Default
0
TDA5251 F1
Version 1.1
Application
[3 – 30]
[3 – 31]
2007-02-26
SET
0
RSSI.wmf