TDA5212_06 INFINEON [Infineon Technologies AG], TDA5212_06 Datasheet - Page 34

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

Wireless Components
U
input. The time constant appearing in this case can be denoted as T3, which
can be calculated with
Figure 4-12
As an example the choice of C2 = 20nF and C = 47nF yields
τ
T
T
This means that in this case the inrush current could flow for a duration of
0.64ms but stops already after 0.49ms when the U
T3 should always be chosen to be shorter than T2.
It has to be noted finally that during the turn-on duration T2 the overall device
power consumption is increased by the 240µA needed to charge C.
The precharge circuit may be disabled if C2 is not equipped. This yields a T2
close to zero. Note that the sum of R4 and R5 has to be 600k Ω in order to pro-
duce 3V at the THRES pin as this voltage is internally used also as the refer-
ence for the FSK demodulator.
2
2
3
Smax
= 0.4ms
= 0.64ms
= 0.49ms
= 2.5V which is also the approximate operating point of the data filter
Us
Uc
Voltage transient on capacitor C attached to pin 20
4 - 13
T
3
=
U
T3
240
S
max
µ
×
A
C
=
240
2
5 .
V
µ
A
×
Smax
C
Specification, December 2006
limit has been reached.
Applications
TDA 5212
e-Fkt2.WMF