Philips Semiconductors
Objective specification
Low power dual-band GSM transceiver
with an image rejecting front-end
FEATURES
•
Dual-band application for Global System for Mobile
communication (GSM) and Digital Cellular
communication Systems (DCS)
•
Low noise and wide dynamic range single Intermediate
Frequency (IF) transceiver
•
More than 30 dB on-chip image rejection in the receiver
•
More than 60 dB gain control range
•
I/Q demodulator with high performance integrated
baseband channel filter
•
High precision I/Q modulator
•
Transmit modulation loop architecture including offset
mixer and phase detector
•
Dual Phase-Locked Loop (PLL) with on-chip IF Voltage
Controlled Oscillator (VCO)
•
Fully differential design minimizing cross-talk and spurii
•
3-wire serial bus interface
•
Functional down to 2.7 V and up to 3.3 V
•
LQFP48 package.
APPLICATIONS
•
GSM 900 MHz hand-held transceiver
•
GSM/DCS dual-band solution with the UAA2077CM
(down to 3.2 V) or UAA2077TS/D (down to 2.7 V).
GENERAL DESCRIPTION
The UAA3522HL integrates the receiver and most of the
transmitter section of a GSM hand-held transceiver. It also
integrates the receiver IF and the transmitter section of a
DCS transceiver.
The receiver comprises an RF and an IF section. The RF
(GSM) front-end amplifies the aerial signal, converts the
chosen channel frequency to an IF of 200 MHz, and also
provides more than 30 dB of image suppression. Some
selectivity is provided at this stage by an off-chip bandpass
pre-filter. The IF section further amplifies the chosen
channel, maintains the gain at the required level,
demodulates the signal into I and Q components, and
provides channel selectivity at a baseband stage using a
high performance integrated low-pass filter. The IF gain
can be varied over a range of more than 60 dB. The offset
at the I and Q outputs can be cancelled out by software
using the 3-wire serial programming bus.
UAA3522HL
The input Low Noise Amplifier (LNA) can be switched off
via the bus to allow accurate calibration in the offset
cancellation mode.
The transmitter comprises a high precision I/Q modulator
and modulation loop architecture. The I/Q modulator
converts the baseband modulation frequency to the
transmit IF. The modulation loop architecture, which
includes an on-chip offset mixer and phase detector,
controls an external transmit RF VCO which converts the
transmit modulated IF signal to RF.
A receive RF VCO provides the Local Oscillator (LO)
signal to the image rejection mixers in the RF receiver. An
IF VCO provides the LO signal to the I/Q demodulator and
I/Q modulator in the receiver and transmitter sections
respectively.
The frequencies of the RF VCO and the IF VCO are set by
internal PLL circuits, which are programmable via the
3-wire serial bus. The RF and IF PLL comparison
frequencies are 200 kHz and 1 MHz respectively, derived
from a 13 MHz reference signal which has to be supplied
externally. The quadrature RF LO signals required by the
image rejection mixers are obtained using on-chip
Resistor Capacitor (RC) networks. The quadrature IF LO
signals required by the I/Q modulator and I/Q demodulator
are obtained by dividing the frequency of the IF VCO
signal.
The IC can be powered on in either receiver (RX),
transmitter (TX) or synthesizer (SYN) operating mode
depending on the logic level at pins RXON, TXON and
SYNON, respectively. Alternatively, an operating mode
can be selected by software using the 3-wire serial
programming bus. In RX or TX mode, only those sections
of the IC which are required are switched on.
The GSM or DCS band is selected by the 3-wire serial
programming bus. When activating RX mode for DCS
applications, the receiver RF section can be disabled by
software so that only the receiver IF section is
powered-on.
The SYN mode is used to power-on the synthesizer prior
to activating the RX or TX mode. In SYN mode, some
internal LO buffers are also powered-on to minimize the
‘pulling’ effect of the VCO when either the receiver or the
transmitter are switched on.
2000 Feb 18
2
Philips Semiconductors
Objective specification
Low power dual-band GSM transceiver
with an image rejecting front-end
PINNING
SYMBOL
V
CCIF1
QA
QB
IA
IB
REFAGC
GNDIF2
RXIIFA
RXIIFB
V
CCIF2
TXON
V
CCIFLO
IFLOC
IFLOE
GNDIFLO
CPOIF
GNDCPIF
V
CCCPIF
EN
DATA
CLK
GNDSYN
REFIN
V
CCSYN
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
DESCRIPTION
IF section of RF receiver supply
voltage 1
Q path A baseband input/output
Q path B baseband input/output
I path A baseband input/output
I path B baseband input/output
AGC reference resistor
I/Q modulator and I/Q demodulator
ground 2
RX IF input A to AGC amplifier
RX IF input B to AGC amplifier
I/Q modulator and I/Q demodulator
supply voltage 2
TX mode control pin
IF LO supply voltage
IF LO signal input from
IF VCO resonator
IF LO signal input from
IF VCO resonator
IF LO ground
IF charge pump output
IF charge pump and phase
detector ground
IF charge pump and phase
detector supply voltage
serial programming bus enable
control pin
serial programming bus data input
serial programming bus clock input
synthesizer ground
13 MHz reference input
synthesizer supply voltage
RXIRFA
RXIRFB
GNDRF
TXIFA
TXIFB
RXOIFA
RXOIFB
GNDIF1
41
42
43
44
45
46
47
48
RESEXT
TXIRFA
TXIRFB
V
CCRF
37
38
39
40
PHDOUT
V
CCPHD
35
36
SYMBOL
V
CCCPRF
CPORF
GNDCP
SYNON
V
CCRFLO
RFLOC
RFLOE
GNDRFLO
RXON
GNDPHD
PIN
25
26
27
28
29
30
31
32
33
34
UAA3522HL
DESCRIPTION
RF charge pump and phase
detector supply voltage
RF charge pump output
RF charge pump ground
SYN mode control pin
RF LO section supply voltage
LO signal input from RF VCO
LO signal input from RF VCO
RF LO section ground
RX mode control pin
transmit modulation loop charge
pump ground
charge pump output
transmit modulation loop charge
pump supply voltage
reference resistor for transmit
modulation loop
TX RF VCO signal input
TX RF VCO signal input
RF receiver and transmit
modulation loop supply voltage
RF receiver input A
RF receiver input B
RF receiver and transmit
modulation loop ground
transmit IF external filter A
transmit IF external filter B
receiver IF output A
receiver IF output B
IF section of RF receiver ground 1
2000 Feb 18
5
京公网安备 11010802033920号
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