TDA5250D2_07 INFINEON [Infineon Technologies AG], TDA5250D2_07 Datasheet - Page 19

• Manufacturer Part Number: TDA5250D2_07
• Description: ASK/FSK 868MHz Wireless Transceiver
• Manufacturer: INFINEON [Infineon Technologies AG]

2.4
2.4.1
The power amplifier is operating in C-mode. It can be used in either high or low power mode. In
high-power mode the transmit power is approximately +13dBm into 50 Ohm at 5V and +4dBm at
2.1V supply voltage. In low power mode the transmit power is approximately -7dBm at 5V and -
32dBm at 2.1V supply voltage using the same matching network. The transmit power is controlled
by the D0-bit of the CONFIG register (subaddress 00H) as shown in the following Table 2-2. The
default output power mode is high power mode.
Table 2-2
In case of ASK modulation the power amplifier is turned fully on and off by the transmit baseband
data, i.e. 100% On-Off-Keying.
2.4.2
The LNA is an on-chip cascode amplifier with a voltage gain of 15 to 20dB and symmetrical inputs.
It is possible to reduce the gain to 0 dB via logic.
Table 2-3
2.4.3
The Double Balanced 1
down to the intermediate frequency (IF) at approximately 290MHz. The local oscillator frequency is
generated by the PLL synthesizer that is fully implemented on-chip as described in Section 2.4.5.
This local oscillator operates at approximately 1157MHz in receive mode providing the above
mentioned IF frequency of 290MHz. The mixer is followed by a low pass filter with a corner
frequency of approximately 350MHz in order to prevent RF and LO signals from appearing in the
290MHz IF signal.
2.4.4
The Low pass filter is followed by 2 mixers (inphase I and quadrature Q) that convert the 289MHz
IF signal down to zero-IF. These two mixers are driven by a signal that is generated by dividing the
local oscillator signal by 4, thus equalling the IF frequency.
Data Sheet
Bit
D0
Bit
D4
Functional Block Description
Power Amplifier (PA)
Low Noise Amplifier (LNA)
Downconverter 1
Downconverter 2
LNA_GAIN
Sub Address 00H: CONFIG
Sub Address 00H: CONFIG
Function
PA_PWR
Function
st
Mixer converts the input frequency (RF) in the range of 868-870 MHz
st
nd
0= low TX Power, 1= high TX Power
Mixer
I/Q Mixers
0= low Gain, 1= high Gain
19
Description
Description
Functional Description
Default
Default
TDA5250 D2
Version 1.7
1
1
2007-02-26