ATA5757 ATMEL Corporation, ATA5757 Datasheet - Page 11

• Manufacturer Part Number: ATA5757
• Description: (ATA5756 / ATA5757) UHF ASK/FSK TRANSMITTER
• Manufacturer: ATMEL Corporation

Application Circuits
4702H–RKE–09/04
For the supply voltage blocking capacitor C
(see Figure 10 on page 12 and Figure 11 on page 13). C
loop antenna to the power amplifier. For C
achieve a better tolerance value and to enable it to realize Z
with standard values.
Together with the pins of ATA5756 and the PCB board wires, C
loop that suppresses the 1
Normally, the best suppression is achieved when C
the pins ANT1 and 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
runs on the load resonance frequency of the crystal. Normally, a value of 10 pF results
in a 12 pF load-capacitance crystal due to the board parasitic capacitances and the
inductive impedance of the XTO1 pin.
1
(50 nH to 100 nH) can be printed on the PCB. C
st
harmonic, hence the position of C
2
, two capacitors in series should be used to
3
, a value of 68 nF/X7R is recommended
4
ATA5756/ATA5757
should be selected so that the XTO
1
is placed as close as possible to
1
and C
Load,opt
1
1 forms
on the PCB is important.
2
are used to match the
by using capacitors
a series resonance
11