ATA5279-PLQW Atmel, ATA5279-PLQW Datasheet - Page 29

• Manufacturer Part Number: ATA5279-PLQW
• Description: RF Wireless Misc High-end multiple antenna driver IC
• Manufacturer: Atmel

Specifications of ATA5279-PLQW

• Package / Case: VQFN-48
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9125L–RKE–03/11
See the following description for details:
Mean value measured during an LF carrier transmission with the desired output current.
P
Alternative formula for calculating the output power.
Note:
The input power determination should be done by transmitting a single LF carrier burst with a
length of for example 8ms. The required electrical data needs to be recorded with a digital
sampling oscilloscope (DSO) and a current probe. Note that the start-up phase of the LF field
must not be used for reading out the data.
Figure 4-2.
Note:
The power dissipation of the external components depends on their parameters and the sup-
ply current. Regarding choke L
it is the forward biasing voltage. In addition, the equivalent series resistance (ESR) of the
charging capacitor C
Figure 4-1 on page
P
P
P
P
diss,ext
diss,tot
in
out
out
=
=
=
U
is the sum of power dissipated by the external components.
The output power can either be calculated by using the impedance of the antenna or by mea-
suring the peak-to-peak amplitude of the sinusoidal voltage applied to the antenna. As the
impedance may change under load conditions, it is recommended to use the formula with the
peak-to-peak antenna voltage.
If the VDS output voltage regulation fails due to too high input currents or too high output volt-
age, the power dissipation increases up to 40%
VS
=
I
------------ -
I
------------ -
Ant,p
Ant,p
P
2
2
in
I
VBATT
–
Power Dissipation on Chip Measured at Application Board ATAB5279
2
P
U
----------------- -
2
out
Z
Ant,pp
27).
3
Ant
is important. The devices' names refer to the application schematic (see
14.00
12.00
10.00
8.00
6.00
4.00
2.00
2
+
+
8.0
P
P
diss,ext
diss,ext
2
9.0
, it is the DC resistance, regarding the freewheeling diode D
Z(Ant) = 12.5Ω
I(Ant) = 700 mAp
10.0
Supply Voltage V
11.0
Z(Ant) = 12.5Ω
I(Ant) = 1000 mAp
12.0
13.0
S
(V)
14.0
Atmel ATA5279
15.0
16.0
29
2
,