ATA8741 ATMEL Corporation, ATA8741 Datasheet - Page 12

• Manufacturer Part Number: ATA8741
• Manufacturer: ATMEL Corporation

8. Application
12
ATA8741
For the blocking of the supply voltage, a capacitor value of C
and C
22 pF/NP0 and C
should be used to achieve a better tolerance value and to have the possibility of realizing the
Z
Together with the pins and the PCB board wires C
presses the 1
suppression is achieved when C
The loop antenna should not exceed a width of 1.5 mm, otherwise the Q-factor of the loop
antenna is too high.
L
load resonance frequency of the crystal. Normally, a value of 12 pF results for a 15 pF
load-capacitance crystal.
Figure 8-1.
Load,opt
1
(50 nH to 100 nH) can be printed on PCB. C
2
using standard valued capacitors.
are used to match the loop antenna to the power amplifier, where C
GND
VS
st
ESD Protection Circuit
harmonic, hence the position of C
2
is 10.8 pF/NP0 (18 pF + 27 pF in series); for C
CLK
1
is placed as close as possible to the pins ANT1 and ANT2.
PA_ENABLE
4
should be selected that the XTO runs on the
1
on the PCB is important. Normally the best
1
forms a series resonance loop that sup-
ANT1
ANT2
3
= 68 nF/X7R is recommended. C
XTAL
2
two capacitors in series
ENABLE
9140B–INDCO–07/09
1
typically is
1