TDA5251 Infineon Technologies, TDA5251 Datasheet - Page 66

• 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

Timing for data detection looks like the following. Two settings are possible: „Continuous“ and
„Single Shot“, which can be set by D5 and D6 in register 00H.
Figure 3-29
Note 1: Chip internal signal „Sequencer enables data detection“ has a LOW to HIGH transition
about 2.6ms after RX is activated (see Figure 2-15).
Note 2: The positive edge of the „Window Count Complete“ signal latches the result of comparison
of the analog to digital converted RSSI voltage with TH3 (register 08H). A logic combination of this
output and the result of the comparison with single/double TH x defines the internal signal
„data_valid“.
Figure 3-29 shows that the logic is ready for the next conversion after 3 periods of the data signal.
Timing in Single Shot mode can be seen in the subsequent figure:
Figure 3-30
Data Sheet
Frequency Detection timing in continuous mode
Frequency Detection timing in Single Shot mode
Compare with double
(Frequency) Window
Compare with single
Sequenzer enables
TH and latch result
TH and latch result
Compare with double
(Frequency) Window
Compare with single
Sequenzer enables
TH and latch result
TH and latch result
Count Complete
Counter Reset
data detection
Count Complete
Counter Reset
data detection
Gate time
Gate time
Data
start of conversion
Data
start of conversion
reset
reset
no possible start of next conversion
count
because of Single Shot Mode
66
comp.
count
possible start of next conversion
comp.
comp.
ready*
comp.
ready*
reset
count
t
t
t
t
t
t
t
Frequ_Detect_Timing_singleShot_wmf
Frequ_Detect_Timing_continuous.wmf
comp.
t
t
t
t
t
t
t
TDA5251 F1
Version 1.1
Application
2007-02-26