ATA5423 ATMEL Corporation, ATA5423 Datasheet - Page 22

• Manufacturer Part Number: ATA5423
• Manufacturer: ATMEL Corporation

Table 3-7.
3.13
22
Frequency (MHz) TX Current (mA) Output Power (dBm) R1 (k )
433.92
433.92
433.92
868.3
868.3
868.3
315
315
315
345
345
345
915
915
915
Output Power and TX Supply Current versus Supply Voltage and Temperature
ATA5423/25/28/29 [Preliminary]
Measured Output Power and Current Consumption with VS1 = VS2 = 3 V, T
10.5
16.7
11.2
17.8
11.5
16.3
8.5
8.6
9.3
Table 3-8 on page 22
VS = VS1 = VS2 in the 433.92 MHz and 6.2 dBm case versus temperature and supply voltage
measured according to
opposed to the receiver sensitivity, the supply voltage has here the major impact on output
power variations because of the large signal behavior of a power amplifier. Thus, a two battery
system with voltage regulator or a 5 V system shows much less variation than a 2.4 V to 3.6 V
one battery system because the supply voltage is then well within 3.0 V and 3.6 V.
The reason is that the amplitude at the output RF_OUT with optimum load resistance is
AVCC - 0.4 V and the power is proportional to (AVCC – 0.4 V)
changed. This means that the theoretical output power reduction if reducing the supply voltage
from 3.0 V to 2.4 V is 10 log ((3 V – 0.4 V)
ciple behavior in the measurement. This is not the same case for higher voltages, since here
increasing the supply voltage from 3 V to 3.6 V should theoretical increase the power by 1.8 dB;
but a gain of only 0.8 dB in the measurement shows that the amplitude does not increase with
the supply voltage because the load impedance is optimized for 3 V and the output amplitude
stays more constant.
Table 3-8.
T
T
T
amb
amb
amb
VS =
=
= +25°C
= +85°C
–
40°C
Measured Output Power and Supply Current at 433.92 MHz, PWR_H = GND
10.5
–
0.4
5.7
0.1
6.2
5.4
9.5
11
0.3
shows the measurement of the output power for a typical device with
Figure 3-10 on page 21
10.19 mA
10.62 mA
3.8 dBm
4.6 dBm
11.4 mA
3.8 dBm
2.4 V
56
27
27
56
22
22
33
15
22
VPWR_H
2
AVCC
AVCC
AVCC
AVCC
AVCC
/(2.4 V – 0.4 V)
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
with components according to
R
Lopt
2500
2300
1170
920
350
890
300
471
245
10.19 mA
11.19 mA
12.02 mA
5.5 dBm
6.2 dBm
5.4 dBm
3.0 V
2
( )
) = 2.2 dB.
L1 (nH)
amb
2
82
68
56
56
47
33
12
15
10
if the load impedance is not
= 25°C
Table 3-8
Q
28
32
35
40
38
43
58
54
57
L1
C1 (pF) C3 (pF)
10.78 mA
11.79 mA
12.73 mA
shows that prin-
6.2 dBm
7.1 dBm
6.3 dBm
0.75
3.6 V
1.5
2.2
3.9
1.5
2.7
1.0
1.0
1.5
Table
4841A–RKE–02/05
3-7. As
3.3
0
0
0
0
0
0
0
0