uaa2073m NXP Semiconductors, uaa2073m Datasheet - Page 2

• Manufacturer Part Number: uaa2073m
• Description: Image Rejecting Front-end For Gsm Applications
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FEATURES
APPLICATIONS
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.
ORDERING INFORMATION
1995 Dec 07
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).
900 MHz front-end for GSM hand-portable equipment
Compact digital mobile communication equipment
TDMA receivers.
Image rejecting front-end
for GSM applications
TYPE NUMBER
UAA2073M
SSOP20
NAME
plastic shrink small outline package; 20 leads; body width 4.4 mm
2
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
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.
DESCRIPTION
PACKAGE
IF frequency can form the IF signal.
Product specification
UAA2073M
SOT266-1
VERSION