Philips UAA2073AM Datasheet

INTEGRATED CIRCUITS

DATA SH EET

UAA2073AM

Image rejecting front-end
for GSM applications

Product specification
Supersedes data of 1996 Oct 23
File under Integrated Circuits, IC17

1997 Jan 27

Philips Semiconductors Product specification

Image rejecting front-end
for GSM applications

FEATURES

• Low-noise, wide dynamic range amplifier

• Very low noise figure

• Dual balanced mixer for at least 30 dB on-chip image

rejection

• IF I/Q combination network for 175 MHz

• Down-conversion mixer for closed-loop transmitters

• Independent TX/RX fast on/off power-down modes

• Very small outline packaging

• Very small application (no image filter).

APPLICATIONS

• 900 MHz front-end for GSM hand-portable equipment

• Compact digital mobile communication equipment

• TDMA receivers.

GENERAL DESCRIPTION

UAA2073AM contains both a receiver front-end and a high
frequency transmit mixer intended for GSM
(Global System for Mobile communications) cellular
telephones. Designed in an advanced BiCMOS process it
combines high performance with low power consumption
and a high degree of integration, thus reducing external
component costs and total front-end size.

The main advantage of the UAA2073AM is its ability to
provide over 30 dB of image rejection. Consequently, the
image filter between the LNA and the mixer is suppressed
and the duplexer design is eased, compared with a
conventional front-end design.

UAA2073AM

Image rejection is achieved in the internal architecture by
two RF mixers in quadrature and two all-pass filters in
I and Q IF channels that phase shift the IF by 45° and 135°
respectively. The two phase shifted IFs are recombined
and buffered to furnish the IF output signal.

This means that signals presented at the RF input at
LO − IF frequency are rejected through this signal
processing while signals at LO + IF frequency can form the
IF signal.

The receiver section consists of a low-noise amplifier that
drives a quadrature mixer pair. The IF amplifier has
on-chip 45° and 135° phase shifting and a combining
network for image rejection.The IF driver has differential
open-collector type outputs.

The LO part consists of an internal all-pass type phase
shifter to provide quadrature LO signals to the receive
mixers. The all-pass filters outputs are buffered before
being fed to the receive mixers.

The transmit section consists of a down-conversion mixer
and a transmit IF driver stage. In the transmit mode an
internal LO buffer is used to drive the transmit IF
down-conversion mixer.

All RF and IF inputs or outputs are balanced to reduce
EMC issues.

Fast power-up switching is possible. A synthesizer-on
(SX) mode enables LO buffers independent of the other
circuits. When SXON pin is HIGH, all internal buffers on
the LO path of the circuit are turned on, thus minimizing
LO pulling when remainder of receive chain is
powered-up.

ORDERING INFORMATION

TYPE

NUMBER

UAA2073AM SSOP20 plastic shrink small outline package; 20 leads; body width 4.4 mm SOT266-1

1997 Jan 27 2

NAME DESCRIPTION VERSION

PACKAGE

Philips Semiconductors Product specification

Image rejecting front-end

UAA2073AM

for GSM applications

QUICK REFERENCE DATA

Note 1.

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

V

CC

I

CC(RX)

I

CC(TX)

NF

RX

G

CPRX

IR image frequency rejection 30 45 − dB
T

amb

Note

1. For conditions see Chapters “DC characteristics” and “AC characteristics”.

BLOCK DIAGRAM

supply voltage 3.6 3.75 5.3 V
receive supply current 21 26 32 mA
transmit supply current 9 12 15 mA
noise figure on demonstration board (including matching

− 3.6 4.7 dB

and PCB losses)
conversion power gain 19 22 25 dB

operating ambient temperature −30 +25 +75 °C

handbook, full pagewidth

V

CC1

RFINA
RFINB

GND1

V

CC2

RXON

TXON

SXON

GND2

n.c. n.c. SBS

4

5
6

7

15

11
12

REGULATORS

10

16

2 3

LNA

low-noise

amplifier

CURRENT

RX
TX
IF
LO

UAA2073AM

QUADRATURE

PHASE

SHIFTER

+45

+135

o

C

o

C

TRANSMIT SECTION

LOCAL OSCILLATOR

SECTION

LOINA

1

IF

COMBINER

RECEIVE SECTION

MIXER

81718

9

TXINATXINBLOINB

20

19

14

13

MGD149

IFA

IFB

TXOIFA
TXOIFB

Fig.1 Block diagram.

1997 Jan 27 3

Philips Semiconductors Product specification

Image rejecting front-end
for GSM applications

PINNING

SYMBOL PIN DESCRIPTION

SBS 1 sideband selection (should be

grounded for f

LO<fRF

n.c. 2 not connected
n.c. 3 not connected
V

CC1

4 supply voltage for receive and

transmit sections
RFINA 5 RF input A (balanced)
RFINB 6 RF input B (balanced)
GND1 7 ground 1 for receive and transmit

sections
TXINA 8 transmit mixer input A (balanced)
TXINB 9 transmit mixer input B (balanced)
SXON 10 hardware power-on of LO section

(including buffers to RX and TX)
RXON 11 hardware power-on for receive

section and LO buffers to RX
TXON 12 hardware power-on for transmit

section and LO buffers to TX
TXOIFB 13 transmit mixer IF output B

(balanced)
TXOIFA 14 transmit mixer IF output A

(balanced)
V

CC2

15 supply voltage for LO section
GND2 16 ground 2 for LO section
LOINB 17 LO input B (balanced)
LOINA 18 LO input A (balanced)
IFB 19 IF output B (balanced)
IFA 20 IF output A (balanced)

)

handbook, halfpage

UAA2073AM

SBS

1

n.c.

2

n.c.

3

V

4

CC1

RFINA

5

UAA2073AM

6

RFINB

7

GND1

TXINA

8
9

TXINB

10

SXON RXON

Fig.2 Pin configuration.

MGD150

20
19
18
17
16
15
14
13
12
11

IFA
IFB
LOINA
LOINB
GND2
V

CC2

TXOIFA
TXOIFB
TXON

1997 Jan 27 4

Philips Semiconductors Product specification

Image rejecting front-end
for GSM applications

FUNCTIONAL DESCRIPTION
Receive section

The circuit contains a low-noise amplifier followed by two
high dynamic range mixers. These mixers are of the
Gilbert-cell type. The whole internal architecture is fully
differential.

The local oscillator, shifted in phase to 45° and 135°,
mixes the amplified RF to create I and Q channels.
The two I and Q channels are buffered, phase shifted by
45° and 135° respectively, amplified and recombined
internally to realize the image rejection.

Pin SBS allows sideband selection:

• f

LO>fRF

• fLO<fRF (SBS = 0).
Where fRF is the frequency of the wanted signal.

(SBS = 1)

UAA2073AM

Balanced signal interfaces are used for minimizing
crosstalk due to package parasitics. The RF differential
input impedance is 150 Ω (parallel real part), chosen to
minimize current consumption at best noise performance.

The IF output is differential and of the open-collector type,
tuned for 175 MHz. Typical application will load the output
with a 680 Ω resistor load at each IF output, plus a 1 kΩ
load consisting in the input impedance of the IF filter or in
the input impedance of the matching network for the IF
filter. The power gain refers to the available power on this
1kΩ load. The path to V
achieved via tuning inductors. The output voltage is limited
to VCC+3Vbe or 3 diode forward voltage drops.

Fast switching, on/off, of the receive section is controlled
by the hardware input RXON.

for the DC current should be

CC

handbook, full pagewidth

V

CC1

RFINA
RFINB

GND1

LNA

MIXER

MIXER

LOIN

IF

amplifier

IF

amplifier

+45

+135

o

o

RXON

Fig.3 Block diagram, receive section.

SBS

IF

COMBINER

MBH188


IFA

IFB

1997 Jan 27 5

Philips Semiconductors Product specification

Image rejecting front-end
for GSM applications

Local oscillator section

The Local Oscillator (LO) input directly drives the two
internal all-pass networks to provide quadrature LO to the
receive mixers.

The LO differential input impedance is 50 Ω (parallel real
part).

A synthesizer-on (SX) mode is used to power-up the
buffering on the LO inputs, minimizing the pulling effect on
the external VCO when entering transmit or receive
modes.

This mode is active when the SXON input is HIGH. Table 1
shows status of circuit in accordance with TXON, RXON
and SXON inputs.

handbook, halfpage

to RX

UAA2073AM

Transmit mixer

This mixer is used for down-conversion to the transmit IF.
Its inputs are coupled to the transmit RF and down-convert
it to a modulated transmit IF frequency which is phase
locked with the baseband modulation.

The transmit mixer provides a differential input at 200 Ω
and a differential output driver buffer for a 1 kΩ load.
The IF outputs are low impedance (emitter followers).

Fast switching, on/off, of the transmit section is controlled
by the hardware input TXON.

V

CC2

RXON

TXON

SXON

GND2

LOINA

QUAD

LOINB

Fig.4 Block diagram, LO section.

to TX

MBH189


handbook, halfpage

LOIN

Fig.5 Block diagram, transmit mixer.

TX MIXER

TXOIFA
TXOIFB

MBH190

TXINBTXON

TXINA

1997 Jan 27 6