ATA5743 ATMEL Corporation, ATA5743 Datasheet - Page 23

• Manufacturer Part Number: ATA5743
• Description: Ata5743 Uhf Ask/fsk Receiver
• Manufacturer: ATMEL Corporation

Figure 6-20. Output of Digital Noise at the End of the Data Stream
Figure 6-21. Automatic Noise Suppression
Figure 6-22. Occurrence of a Pulse at the End of the Data Stream
6.5.2
4839B–RKE–08/05
Controlled Noise Suppression by the Microcontroller
Data_out (DATA)
DATA_CLK
DATA_CLK
Data_out (DATA)
Dem_out
Data_out (DATA)
DATA_CLK
Bit-check
mode
Bit-check
mode
Bit check ok
Bit check ok
The controlled noise suppressionis illustrated in
(see
of a valid data stream. To suppress the noise, the pin POLLING/_ON must be set to Low. The
receiver remains in receiving mode. Then, the OFF command causes the change to the start-up
mode. The programmed sleep time (see
level at pin POLLING/_ON is Low, but the bit check is active. The OFF command activates the
bit check also if the pin POLLING/_ON is held to Low. The receiver changes back to receiving
mode if the bit check was successful. To activate the polling mode at the end of the data trans-
mission, the pin POLLING/_ON must be set to High.
This way of suppressing the noise is recommended if the data stream is not Manchester or
Bi-phase coded.
Preburst
Preburst
Receiving mode,
data clock control
logic active
Table 6-9 on page
Receiving mode,
data clock control
logic active
Receiving mode,
data clock control
logic active
1
Data stream
Timing error
Data
Data
1
1
26) in the OPMODE register is set to “0”, digital noise appears at the end
Digital Noise
(
T
ee
T
Receiving mode,
bit check aktive
ee
< T
Lim_min
Bit-check
mode
or T
T
Digital Noise
Pulse
Lim_max
Table 6-7 on page
Bit check ok
Bit check ok
< T
Digital noise
Figure 6-23 on page
ee
Preburst
Preburst
Bit-check mode
< T
Receiving mode,
data clock control
logic active
Receiving mode,
data clock control
logic active
Lim_min_2T
26) will not be executed because the
Data
Data
or T
ee
> T
24. If the bit Noise_Disable
Lim_max_2T
Receiving mode,
bit check aktive
Digital Noise
Bit-check
mode
)
ATA5743
23