tda5255e1 Infineon Technologies Corporation, tda5255e1 Datasheet - Page 31

• Manufacturer Part Number: tda5255e1
• Description: Ask/fsk 434mhz Wireless Transceiver
• Manufacturer: Infineon Technologies Corporation

Confidential
Note: The time delay between start of ON time and the 15µs LOW impulse is 2.6ms + 3 period of
data rate.
If ADC & Data Detect Logic are in continuous mode the 15µs LOW impulse is applied at PwdDD
after each data valid decision.
In self polling mode if D9=0 (Register 00h) and when PwdDD pin level is HIGH the CLK output is
on during ON time and off during OFF time. If D9=1, the CLK output is always on.
TIMER MODE: Only the internal Timer (determined by the ON_TIME and OFF_TIME registers) is
active to support an external logic with periodical Interrupts. After ON_TIME + OFF_TIME a 15µs
LOW impulse is applied at the PwdDD pin (Pin 27).
Figure 2-11
Please note to add a serial resistor in the VDD supply line as mentioned on page 13 and in
Section 4.4
2.4.17
Data signals generate a typical spectrum and this can be used to determine if valid data is on air.
Figure 2-12
The “data valid” criterion is generated from the result of RSSI-TH3 comparison and t
TH1 and TH2 result as shown below. In case of Manchester coding the 0,5*TH1 and 0,5*TH2 gives
improved performance.
Preliminary Specification
TIMER MODE
PwdDD pin in
Data Valid Detection, Data Pin
Timing for Timer Mode
Frequency and RSSI Window
Action
RSSI
Amplitude
15µs
Register 04H
ON_TIME
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
x x x x x x x x x x x x x
f
Register 05H
OFF_TIME
Frequency & RSSI Window
31
DATA on air
no DATA on air
15µs
Register 04H
ON_TIME
Frequency
Functional Description
t
t
TDA5255 E1
Version 1.1
timing_timermode.wmf
GATE
data_rate_detect.wmf
2002-11-28
between