ATA5811-PLQX Atmel, ATA5811-PLQX Datasheet - Page 19

• Manufacturer Part Number: ATA5811-PLQX
• Manufacturer: Atmel

Specifications of ATA5811-PLQX

• Operating Temperature (min): -40C
• Operating Temperature (max): 105C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 7mm
• Product Height (mm): 0.9mm
• Product Length (mm): 7mm
• Lead Free Status / Rohs Status: Compliant

Table 7. Measured Output Power and Current Consumption with VS1 = VS2 = 3 V, T
Output Power and TX Supply
Current versus Supply
Voltage and Temperature
4689B–RKE–04/04
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
10.5
16.7
11.2
17.8
11.5
16.3
8.5
8.6
9.3
Figure 16. Power Setting and Output Matching
Table 8 on page 20 shows the measurement of the output power for a typical device
with VS1 = VS2 = VS in the 433.92 MHz and 6.2 dBm case versus temperature and
supply voltage measured according to Figure 16 on page 19 with components according
to Table 7. As 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)
not changed. This means that the theoretical output power reduction if reducing the sup-
ply voltage from 3.0 V to 2.4 V is 10 log ((3 V - 0.4 V)
on page 20 shows that principle 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 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.
10.5
-0.3
0.4
5.7
0.1
6.2
5.4
9.5
11
RF
ATA5811/ATA5812 [Preliminary]
56
27
27
56
22
22
33
15
22
OUT
C
3
VPWR_H
VPWR_H
AVCC
AVCC
AVCC
AVCC
GND
GND
GND
GND
GND
GND
C
1
L
R
1
1
10
8
9
R
C
Lopt
2
2500
2300
1170
920
350
890
300
471
245
RF_OUT
R_PWR
PWR_H
ATA5811/ATA5812
( )
amb
2
/(2.4 V - 0.4 V)
= 25°C
L1 (nH)
82
68
56
56
47
33
12
15
10
2
if the load impedance is
Q
28
32
35
40
38
43
58
54
57
L1
2
) = 2.2 dB. Table 8
C1 (pF) C3 (pF)
0.75
1.5
2.2
3.9
1.5
2.7
1.0
1.0
1.5
3.3
0
0
0
0
0
0
0
0
19