Philips Semiconductors
Analog cordless telephone IC
Product specification
UAA2062
LNA GAIN SELECTION
The LNA has an internal programmable voltage conversion gain. This allows to tune the gain in order to achieve the best
compromise in term of performance. The LNA gain is given with a reference value of L = 390 nH (Qloaded = 40) at
50 MHz.
Table 12 LNA gain selection; L = 390 nH at BPFI; QLoaded = 40; f = 50 MHz
BIT 1
0
0
1
1
BIT 0
0
1
0
1
STEP
0
1
2
3
LNA GAIN (dB)
17
19
21
23
LNA INPUT RESISTIVE IMPEDANCE SELECTION
The LNA has an internal programmable input resistive impedance (RIN) in order to improve the duplexer and LNA
performance. To calculate the input resistive impedance we must know the typical LNA gain (i.e. the value of the external
inductance and its Q). A small capacitance at the LNA input is needed to improve matching between LNA and duplexer.
The programmability of tuning the input impedance allows to obtain an optimum sensitivity performance in the active and
in the RX mode of operation.
Table 13 LNA input resistive impedance selection
BIT 1
0
0
1
1
BIT 0
0
1
0
1
STEP
0
1
2
3
TYPICAL LNA INPUT RESISTIVE IMPEDANCE
LNA VOLTAGE
GAIN = 17 dB
LNA VOLTAGE
GAIN = 23 dB
1.2 kΩ
3.0 kΩ
7.1 kΩ
22.9 kΩ
645 Ω
1.6 kΩ
3.8 kΩ
14.5 kΩ
2000 Aug 10
19