uaa2073m NXP Semiconductors, uaa2073m Datasheet - Page 6

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

Philips Semiconductors
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
(parallel real part).
A synthesizer-on (synthon) 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 SYNTHON input is HIGH.
Table 1 shows status of circuit in accordance with TXON,
RXON and SYNTHON inputs.
1995 Dec 07
handbook, halfpage
SYNTHON
Image rejecting front-end
for GSM applications
RXON
TXON
GND2
V CC2
Fig.4 Block diagram, LO section.
REGULATORS
CURRENT
RX
TX
IF
LO
LOINA
QUAD
to RX
LOINB
MBG796
to TX
6
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
and a differential output driver buffer for a 1 k load. The
IF outputs are low impedance (emitter followers).
Fast switching, on/off, of the transmit section is controlled
by the hardware input TXON.
handbook, halfpage
LOIN
Fig.5 Block diagram, transmit mixer.
TXON
SYNTHON
TXINB
TX MIXER
TXINA
Product specification
UAA2073M
MBG797
TXOIFA
TXOIFB