ATA3742_07 ATMEL [ATMEL Corporation], ATA3742_07 Datasheet - Page 14

• Manufacturer Part Number: ATA3742_07
• Description: UHF ASK/FSK Receiver
• Manufacturer: ATMEL [ATMEL Corporation]

14
ATA3742
Figure 5-2.
For best noise immunity it is recommended to use a low span between T
This is achieved using a fixed frequency at a 50% duty cycle for the transmitter preburst. A
“11111...” or “10101...” sequence in Manchester or bi-phase is a good choice given this recom-
mendation. A good compromise between receiver sensitivity and susceptibility to noise is a time
window of ±25% regarding the expected edge-to-edge time t
tain various edge-to-edge time periods, the bit check limits must be programmed according to
the required span.
The bit check limits are determined by means of the formula below:
T
T
Lim_min and Lim_max are defined by a 5-bit word each within the LIMIT register.
Using the above formulas, Lim_min and Lim_max can be determined according to the required
T
minimum edge-to-edge time t
ing Mode” on page
value of the upper limit is Lim_max = 63.
Lim_min
Lim_max
Lim_min
, T
= Lim_min
= (Lim_max – 1)
Lim_max
Valid Time Window for Bit Check
and T
17. Due to this, the lower limit should be set to Lim_min
T
Dem_out
XClk
XClk
. The time resolution when defining T
T
XClk
ee
(t
DATA_L_min
T
T
Lim_max
Lim_min
T
, t
ee
DATA_H_min
1/f
Sig
) is defined according to Section
ee
. Using preburst patterns that con-
Lim_min
and T
Lim_min
Lim_max
10. The maximum
4900B–RKE–11/07
and T
is T
XClk
“Receiv-
Lim_max
. The
.