TDK5111FXT Infineon Technologies, TDK5111FXT Datasheet - Page 26

• Manufacturer Part Number: TDK5111FXT
• Manufacturer: Infineon Technologies

Specifications of TDK5111FXT

• Operating Temperature (min): -40C
• Operating Temperature (max): 125C
• Operating Temperature Classification: Automotive
• Product Depth (mm): 4.4mm
• Operating Supply Voltage (min): 2.1V
• Operating Supply Voltage (typ): 2.5/3.3V
• Lead Free Status / Rohs Status: Compliant

In practice the RF-saturation voltage of the PA transistor and other parasitics reduce the
“critical” R
The output power P
R
The power efficiency (and the bandwidth) increase when operating at a slightly higher
R
The collector efficiency E is defined as
The diagram of Figure 14 was measured directly at the PA-output at V
the matching circuitry decrease the output power by about 1.5 dB. As can be seen from
the diagram, 250 Ω is the optimum impedance for operation at 3 V. For an approximation
of R
and
Figure 14
The DC collector current I
the load resistor R
collector current will show a characteristic dip at the resonance frequency for this type of
“overcritical” operation. The depth of this dip will increase with higher values of R
Data Sheet
L
L
, as shown in Figure 14.
> R
OPT
LC
and P
.
LC
.
OUT
Output power P
at other supply voltages those two formulas can be used:
L
. This is typical for overcritical operation of class C amplifiers. The
o
is reduced by operating in an “overcritical” mode characterised by
18
16
14
12
10
8
6
4
2
0
0
c
of the power amplifier and the RF output power P
o
100
(mW) and collector efficiency E vs. load resistor R
200
P
E =
R
OUT
RL [Ohm]
OPT
26
V
~
300
P
~
S
O
R
I
V
C
OPT
S
400
500
Pout [mW]
10*Ec
S
V 1.1, 2007-09-18
= 3 V. Losses in
Applications
TDK5111F
o
vary with
L
L
.
.