ATA8743 ATMEL Corporation, ATA8743 Datasheet - Page 12

• Manufacturer Part Number: ATA8743
• Manufacturer: ATMEL Corporation

8. Application
12
ATA8743
For the supply-voltage blocking capacitor C
are used to match the loop antenna to the power amplifier, where C
C
value and to have the possibility of realizing the Z
Together with the pins of T5750 and the PCB board wires, C
suppresses the 1
best suppression is achieved when C
ANT2.
The loop antenna should not exceed a width of 1.5 mm, otherwise the Q-factor of the loop
antenna is too high.
L
the load resonance frequency of the crystal. Normally, a value of 12 pF results for a 15 pF
load-capacitance crystal.
Figure 8-1.
1
2
(
is 1 pF/NP0; for C
50 nH to 100 nH) can be printed on PCB. C
GND
VS
ESD Protection Circuit
st
harmonic, hence the position of C
2
two capacitors in series should be used to achieve a better tolerance
CLK
1
PA_ENABLE
is placed as close as possible to the pins ANT1 and
3
, a value of 68 nF/X7R is recommended. C
Load,opt
4
should be selected so that the XTO runs on
1
ANT1
ANT2
by using standard valued capacitors.
on the PCB is important. Normally the
1
forms a series resonance loop that
1
XTAL
typically is 3.9 pF/NP0 and
ENABLE
9152A–INDCO–07/09
1
and C
2