|
|
PDF MH1P Data sheet ( Hoja de datos )
| Número de pieza | MH1P | |
| Descripción | Quadrature Downconverter | |
| Fabricantes | Mitel Networks | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MH1P (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
Supersedes November 1996 version, DS4032 - 1.6
SL1711
Quadrature Downconverter
Preliminary Information
DS4032 - 4.0 October 1997
The SL1711 is a quadrature downconverter, intended
primarily for application in professional and consumer digital
satellite tuners.
The device contains all elements necessary, with the
exception of external local oscillator tank to form a complete
system operating at standard satellite receiver intermediate
frequencies. It is intended for use with external carrier
recovery.
The device includes a low noise RF input amplifier, a
reference VCO with prescaler output buffer and In-phase and
Quadrature mixers with baseband buffer amplifiers containing
AGC gain control.
The SL1711 is optimised to drive a dual ADC converter
such as the VP216.
The SL1711 utilises a power MP package, whereas the
SL1711B variant uses a standard MP16 plastic package and
features a revised operating temperature.
FEATURES
s Single chip system for wideband quadrature
downconversion
s Compatible with all standard high IF frequencies
s Excellent gain and phase match up to 30MHz
baseband
s High output referred linearity for low distortion and
multi channel application
s Simple low component application
s Fully balanced low radiation design with fully
integrated quadrature generation
s High operating input sensitivity
s On-board AGC facility
s On chip oscillator for varactor tuning or SAW
resonator operation
s ESD protection (Normal ESD handling procedures
should be observed)
AGC
IOUT
VEEA
IFINB
IFIN
IVCCA
QOUT
VEEC
1 16
VCCB
VCODIS
VCO B
VCO A
VEEB
PSCAL
PSCALB
VCCC
MH16
AGC
IOUT
VEEA
IFINB
IFIN
IVCCA
QOUT
VEEC
1 16
VCCB
VCODIS
VCO B
VCO A
VEEB
PSCAL
PSCALB
VCCC
Fig. 1 Pin allocation
MP16
ORDERING INFORMATION
SL1711/KG/MH1P (Sticks)
SL1711/KG/MH1Q (Tape and Reel)
SL1711B/KG/MP1S (Sticks)
SL1711B/KG/MP1T (Tape and Reel)
APPLICATIONS
s Satellite receiver systems
s Data communications systems
s Cable systems
1 page  
55
50
45
40
35
30
25
20
15
AGC CONTROL VOLTS
Fig.4 Typical AGC characteristic
+j0.5
j1
+j2
+j0.2
X3
X2
0
0.2
X1
0.5
1
-j0.2
1 1MHz
2 15MHz
3 30MHz
-j0.5
-j1
-j2
Fig. 5 Typical baseband output impedance
SL1711
5
5 Page 
SL1711
APPLICATION NOTES
These application notes should be read in conjunction with
circuit diagrams contained in Fig. 7 and 10, and a
recommended front end tuner solution contained in Fig. 13.
These boards have been designed to demonstrate
performance and to allow for initial evaluation of the SL1711.
Varator Tuned Oscillator
Refer to Fig. 7 circuit diagram and Figs. 11 and 12 PCB
layout.
This application uses a synthesised VCO with a tuning
range of 460 MHz to 500 MHz. The surface mount inductor L1
is 12 nH. The VCO frequency is controlled by the SP5611
synthesiser which is programmed via an I2C bus. The RF input
to the synthesiser is from the SL1711 prescaler outputs
coupled via RF inductors L3 and L4.
For functional checking the VCO can be tuned by
physically shorting the base of transistor T3 to ground and
then adjusting the +30 volt supply to tune the VCO. Under
these conditions, due to the unlocked state of the LO, the
board WILL NOT BE representative of locked gain and phase
match or phase noise performance.
In real applications such the VCO control voltage will be
provided by the QPSK demodulator circuit, such as the
VP305. This circuit provides a line voltage to align the
reference LO in the 1711 in both frequency and phase to the
centre of the modulation bandwidth, normally 402.75 or 479.5
MHz.
As in all feedback loops the bandwidth of the varactor line
must be optimised for the symbol rate of the received
modulation.
It is recommended for optimum performance that the VCO
application is implemented symmetrically, in presented drive
and impedance to the VCO ports, as demonstrated in the
evaluation schematic and PCB.
In the recommended application the varactor diodes are
referenced to the VCO port DC bias voltages. This limits the
minimum tuning voltage on the varactor line to 3V. If lower
tuning voltage is required the tank can be AC coupled to the
VCO ports by 390pF capacitor and a DC reference voltage for
the varactor diodes applied by centre tapping the tank
inductors. NB the varactor diodes require a minimum of 1V
reverse bias for correct operation.
In real applications the maximum tuning range required for
the VCO will be determined by the required lock range of the
tuner and the manufacturing tolerance of the tank, assuming
the quadrature downconverter section will be alignment free.
This tuning range will be typically be much smaller than the
demonstration board, which will consequently improve the
VCO phase noise performance.
This application can be ported direct to real system
implementations. Normal good RF practice must be applied to
the layout implementation.
Prescaler Outputs (varactor tuned VCO)
The VCO frequency divided by 32 is available at the
differential prescaler outputs, pins 10 and 11.
These enable the VCO frequency to be synthesised by a PLL
frequency synthesiser; on the demo board an SP5611 is used
for this function however in a real application this function will
be provided by the QPSK demodulator function contained in
for example the VP305
It is recommended that the prescaler outputs are loaded
symmetrically to balance radiation effects.
Saw Resonator Oscillator
Refer to Fig. 10 circuit diagram and Figs 11 and 12 PCB
layout.
In the standard application the oscillator uses a varactor
diode tuned tank circuit which allows fine tuning of the
oscillator frequency via a voltage control line. This control
voltage is usually derived from the QPSK/FEC decoder
VP305/VP306
Certain applications do not require this fine tune facility so
a fixed frequency application using a SAW resonator has been
developed. In this application the frequency of the oscillator is
determined by the SAW resonator. The SAW is AC coupled
into the VCO pins of the device pins 13 and 14 via 100pF
coupling capacitors.
The SAW resonator used in this application is a ;
Murata Part No SAR479.45MB10X200
Prescaler Outputs (SAWR tuned VCO)
The VCO frequency divided by 32 is available at the
differential prescaler outputs, pins 10 and 11. Normally these
outputs will not be required since the derotation and fine tuning
required will be processed by the QPSK demodulator.
However these frequencies could be used if required for other
system reference frequencies or clocks.
If used it is recommended that the prescaler outputs are
loaded symmetrically to balance radiation effects.
VCO Disable
The on-chip oscillator can be disabled by connecting
VCODIS, pin 15, to ground and enabled by connecting to Vcc
via a 4k7 Ω pull up resistor.
AGC
The AGC facility can be used to control the conversion gain
of the SL1711.
On the demonstration boards the conversion gain is
adjusted by means of a potentiometer, which is set to 2.5V so
giving a conversion gain of 38 dB. The voltage adjustment
range for the AGC is approximately 1.5 to 3.5 V.
It is important that the AGC voltage minimum does not give
a conversion gain of greater than 44dBs otherwise the
channel amplitude match may be degraded. In real
applications the AGC can be either set at a fixed control
voltage or controlled by means of the AGC control signal from
the QPSK demodulator dependant on the overall dynamic
range requirement of the tuner and it’s gain distribution.
11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet MH1P.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MH101 | High Dynamic Range MMIC Mixer |  ETC |
| MH101-PCB | High Dynamic Range MMIC Mixer | ETC |
| MH102 | High Dynamic Range MMIC Mixer | ETC |
| MH103A | High Dynamic Range UMTS-Band MMIC Mixer | ETC |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |