
2000 Feb 17
7
Philips Semiconductors
Objective specification
Low power GSM/DCS/PCS multi-band transceiver
UAA3535HL
IF
SYNTHESIZER AND
VCO
CONTROL
The IF synthesizer is only necessary in transmit mode.
The TX IF VCO and synthesizer section can be
powered-up with the control bit TXIFON; see Table 2.
If TXIFON is not used, the IF VCO and synthesizer section
will be enabled with the signal TXON.
Table 2
IF synthesizer and VCO power control
LNA
POWER CONTROL
When the receiver is on, it is possible to switch-off the low
noise amplifier separately. Separate control of the low
noise amplifier is accomplished by the control bit LNA; see
Table 3.
Table 3
LNA power control
B
AND SELECTION CONTROL
The receiver includes two RF front-end and RF LO
sections; one for GSM where the RF LO is divided-by-2
and fed to the 925 to 960 MHz front-end, and the other
one for DCS and/or PCS where the RF LO is not divided
and fed to the 1805 to 1990 MHz front-end. The selection
of these 2 modes is accomplished by the control bit BND;
see Table 4.
Table 4
Band selection control
S
IDEBAND SELECTION CONTROL
The receiver includes an image rejection front-end which
allows the use of a RF LO 100 kHz below the RF input
frequency (infradyne) or 100 kHz above the RF input
frequency (supradyne). Between these two states the
proper image should be selected for rejection.
The selection of these 2 modes is accomplished by the
control bit SBD; see Table 5.
Table 5
Sideband selection control
TX
CHARGE PUMP CURRENT CONTROL
The transmit modulation loop includes a transmit charge
pump where sink and source currents are determined by
an external resistor. When determined, this nominal
current can be divided-by-1 or 2 to cope with different
transmit VCO gains. The selection of these 2 modes is
accomplished by the control bit TXI; see Table 6.
Table 6
TX charge pump current control
R
EFERENCE DIVIDER CONTROL
The reference divider can be programmed to divide the
external reference frequency by 65 or 130. The selection
of these 2 modes is accomplished by the control bit
REFDIV; see Table 7.
Table 7
Reference divider control
BIT TXIFON
IF SYNTHESIZER AND
VCO MODE
0
1
off
on
BIT LNA
LNA MODE
0
1
off
on
BIT BND
BAND MODE
0
1
GSM
DCS and/or PCS
BIT SBD
SIDEBAND MODE
0
1
supradyne
infradyne
BIT TXI
TX CHARGE PUMP CURRENT MODE
0
1
nominal current
nominal current divided-by-2
BIT REFDIV
REFERENCE DIVIDER MODE
0
1
divide-by-65
divide-by-130