TDA5212_06 INFINEON [Infineon Technologies AG], TDA5212_06 Datasheet - Page 33

• Manufacturer Part Number: TDA5212_06
• Description: ASK/FSK 915MHz Single Conversion Receiver
• Manufacturer: INFINEON [Infineon Technologies AG]

Wireless Components
This circuit charges the capacitor C with an inrush current I
duration of T
age U
these voltages are equal or the duration T
disabled.
τ
as the sum of R1 and R2 is sufficiently large and thus can be neglected. T2 can
then be calculated according to the following formula:
The voltage transient during the charging of C2 is shown in the following figure:
Figure 4-11
The voltage appearing on the capacitor C connected to pin 20 is shown in the
following figure. It can be seen that due to the fact that it is charged by a con-
stant current source it exhibits is a linear increase in voltage which is limited to
2
is the time constant of the charging process of C which can be calculated as
s
2.4V
at the input of the data filter. This voltage is limited to 2.5V. As soon as
3V
U2
2
Voltage appearing on C2 during precharging process
until the voltage U
4 - 12
T
2
=
τ
2
c
ln
τ
2
appearing on the capacitor is equal to the volt-
2






≈
1
20
−
2
k ×
1
3
Ω
4 .
V
2
V
T2
is exceeded the precharge circuit is
C






2
≈
τ
2
⋅
Specification, December 2006
1
6 .
load
of 240µA for a
Applications
TDA 5212
e-fkt1.WMF