TDA7100 Datasheet, PDF (14/41 Pages) Infineon Technologies AG – 434 MHz ASK/FSK Transmitter in 10-pin Package

TDA7100
Functional Description
Table 5
ASKDTA - Power Amplifier
ASKDTA (pin6)
Low¹⁾
Open²⁾, High³⁾
Power Amplifier
OFF
ON
1) Low:
2) Open:
3) High:
Voltage at pin < 0.5V
Pin open
Voltage at pin > 1.5V
The Power Amplifier has an Open Collector output at PAOUT (pin 9) and requires an
external pull-up coil to provide bias. The coil is part of the tuning and matching LC
circuitry to get best performance with the external loop antenna. To achieve the best
power amplifier efficiency, the high frequency voltage swing at PAOUT (pin 9) should be
twice the supply voltage.
The power amplifier has its own ground pin PAGND (pin 8) in order to reduce the amount
of coupling to the other circuits.
2.4.4 Power Modes
The IC provides three power modes, the POWER DOWN MODE, the PLL ENABLE
MODE and the TRANSMIT MODE.
2.4.4.1 Power Down Mode
In the POWER DOWN MODE the complete chip is switched off.
The current consumption is typically 0.3 nA at 3 V 25°C.
The value is typically 5nA at 70°C.
2.4.4.2 PLL Enable Mode
In the PLL ENABLE MODE the PLL is switched on but the power amplifier is turned off
to avoid undesired power radiation during the time the PLL needs to settle. The turn on
time of the PLL is determined mainly by the turn on time of the crystal oscillator and is
less than 1 msec when the specified crystal is used.
The current consumption is typically 3.5 mA.
Data Sheet
14
V 1.0, 2007-05-02