TDA7100 Datasheet, PDF (15/41 Pages) Infineon Technologies AG – 434 MHz ASK/FSK Transmitter in 10-pin Package

TDA7100
Functional Description
2.4.4.3 Transmit Mode
In the TRANSMIT MODE the PLL is switched on and the power amplifier is turned on too.
The current consumption of the IC is typically 7 mA when using a proper transforming
network at PAOUT, see Figure 8.
2.4.4.4 Power mode control
The bias circuitry is powered up via a voltage V > 1.5 V at the pin PDWN (pin10).
When the bias circuitry is powered up, the pins ASKDTA and FSKDTA are pulled up
internally.
Forcing the voltage at the pins low overrides the internally set state.
Alternatively, if the voltage at ASKDTA or FSKDTA is forced high externally, the PDWN
pin is pulled up internally via a current source. In this case, it is not necessary to connect
the PDWN pin, it is recommended to leave it open.
The principle schematic of the power mode control circuitry is shown in Figure 3
PDWN
ASKDTA
FSKDTA
OR
On
Bias
Source
120 kΩ
Figure 3
120 kΩ
PLL
434
MHz
On
PA
FSK
IC
Power mode control circuitry
FSKOUT
PAOUT
Data Sheet
15
V 1.0, 2007-05-02