Philips UAA2073M Datasheet

INTEGRATED CIRCUITS

DATA SH EET

UAA2073M

Image rejecting front-end
for GSM applications

Product specification
Supersedes data of July 1995
File under Integrated Circuits, IC03

1995 Dec 07

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 50 to 100 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

UAA2073M 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 UAA2073M 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.

UAA2073M

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.

For instance, 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.
An internal switch allows to reject the upper or lower image
frequency. Image rejection is at an optimum when the IF is
71 MHz and local oscillator is above the wanted 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
been 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
(synthon) mode enables LO buffers independent of the
other circuits. When SYNTHON 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

NAME DESCRIPTION VERSION

UAA2073M SSOP20 plastic shrink small outline package; 20 leads; body width 4.4 mm SOT266-1

1995 Dec 07 2

PACKAGE

Philips Semiconductors Product specification

Image rejecting front-end

UAA2073M

for GSM applications

QUICK REFERENCE DATA

Note 1.

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

V

CC

I

CC(RX)

I

CC(TX)

NF noise figure on demonstration board (including matching

G

CP

IR image frequency rejection 30 37 − 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

− 3.25 4.3 dB

and PCB losses)
conversion power gain 20 23 26 dB

operating ambient temperature −30 +25 +85 °C

handbook, full pagewidth

V

CC1

RFINA
RFINB

GND1

V

CC2

RXON

TXON

SYNTHON

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

UAA2073M

TRANSMIT SECTION

QUADRATURE

PHASE

SHIFTER

LOCAL OSCILLATOR

SECTION

LOINA

1

IF

COMBINER

RECEIVE SECTION

MIXER

81718

9

TXINATXINBLOINB

20

19

14

13

MBG794

IFA

IFB

TXOIFA
TXOIFB

Fig.1 Block diagram.

1995 Dec 07 3

Philips Semiconductors Product specification

Image rejecting front-end
for GSM applications

PINNING

SYMBOL PIN DESCRIPTION

SBS 1 sideband selection
n.c. 2 not connected
n.c. 3 not connected
V

CC1

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

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

RXON 11 hardware power-on for receive

TXON 12 hardware power-on for transmit

TXOIFB 13 transmit mixer IF output B

TXOIFA 14 transmit mixer IF output A

V

CC2

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)

4 supply voltage for receive and

transmit sections

sections

(including buffers to RX and TX)

section and LO buffers to RX

section and LO buffers to TX

(balanced)

(balanced)

15 supply voltage for LO section

handbook, halfpage

SYNTHON RXON

SBS

1

n.c.

2

n.c.

3

V

4

CC1

RFINA

5

UAA2073M

6

RFINB

7

GND1

TXINA

8
9

TXINB

10

MBG793

Fig.2 Pin configuration.

UAA2073M

20

IFA
IFB

19
18

LOINA
LOINB

17

GND2

16

V

15

CC2

14

TXOIFA

13

TXOIFB
TXON

12
11

1995 Dec 07 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).

(SBS = 1)

UAA2073M

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

The IF output is differential and of the open-collector type,
tuned for 71 MHz. Typical application will load the output
with a differential 500 Ω load; i.e. a 500 Ω resistor load at
each IF output, plus a 1 kΩ to x Ω narrow band matching
network (x Ω being the input impedance of the IF filter).
The path to V
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 is achieved via tuning

CC

handbook, full pagewidth

V

CC1

RFINA
RFINB

GND1

LNA

MIXER

MIXER

LOIN

IF

amplifier

IF

amplifier

+45

+135

o

o

RXONSYNTHON

Fig.3 Block diagram, receive section.

SBS

IFA

IF

COMBINER

IFB

MBG795

1995 Dec 07 5