TDA7100XT Infineon Technologies, TDA7100XT Datasheet - Page 30

• Manufacturer Part Number: TDA7100XT
• Manufacturer: Infineon Technologies

Specifications of TDA7100XT

• Operating Temperature (min): -20C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (min): 2.1V
• Operating Supply Voltage (typ): 2.5/3.3V
• Lead Free Status / Rohs Status: Compliant

Figure 16
The optimum load at the collector of the power amplifier for “critical” operation under
idealized conditions at resonance is:
The theoretical value of R
“Critical” operation is characterized by the RF peak voltage swing at the collector of the
PA transistor to just reach the supply voltage V
The high degree of efficiency under “critical” operating conditions can be explained by
the low power losses at the transistor. During the conducting phase of the transistor, its
collector voltage is very small. This way the power loss of the transistor, equal to i
is minimized. This is particularly true for small current flow angles of
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 17 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
Data Sheet
L
L
, as shown in Figure 17.
> R
LC
.
LC
.
Equivalent power amplifier tank circuit
o
is reduced by operating in an “overcritical” mode characterised by
LC
for an RF output power of P
R
LC
=
2
R
L
*
E =
LC
. 0
3
00316
=
2
C
30
V
2
P
S
V
O
I
*
C
S
S
P
2
.
=
O
1423
R
V
L
S
Ω
o
= 5 dBm (3.16 mW) is:
θ<<π.
S
V 1.0, 2007-05-02
= 3 V. Losses in
Applications
TDA7100
C
*u
CE