ATA2745
5.1 Output Power Measurement
The following output network (Figure 5-1 on page 5) can be used for output power evaluation,
the exact values of L10 and C10 are dependent on the layout.
L10 and C10 form the transformation network to adopt the output impedance of the IC to 50Ω. The
following table shows the values for an output power of 2 mW and an RPWRSET = 1.2 kΩ.
Table 5-1. Transformation Network
f [MHz]
315
433.92
C10 [pF]
2.7
1.8
Figure 5-1. Measurement Output Network
PWRVCC
ANT
L10 [nH]
56
33
VS
L10
ZLoad-opt
C10
50Ω
ZLoad-opt [Ω]
260 + j330
185 + j268
Figure 5-2. Application Circuit
+VS = 2.2 ... 4.0 V
ASK
EN
C6
CLK
3.39 MHz
C5
R4
ASK
1
EN
2
VCC
3
CLK
4
GND
5
LFVCC
6
LFGND
7
C1 LF
8
OR
Power
up
VCO
f
64
f
n
ATA2745
PA
XTO
C2
GND
16
PWRSET
15
PWRVCC
14
RPWRSET
ANT
C4
13
PWRGND1
12
CLoop2
LFeed
CLoop1
PWRGND2
11
XTO1
13.56 MHz
10
NC
C3
9
Antenna
5
4898B–RKE–08/06