SL1714C MITEL [Mitel Networks Corporation], SL1714C Datasheet - Page 13

• Manufacturer Part Number: SL1714C
• Description: Quadrature Downconverter
• Manufacturer: MITEL [Mitel Networks Corporation]

Programming of Synthesisers
SL1714 VCO (480MHz). Since the SL1714 incorporates a
divide by 32 the synthesised frequency that the SP5611 must
be programmed to is 480/32=15MHz.
Example
a) To program the SL1714 to 480MHz.
0F00 is the programmable divider information (bytes 2 and 3).
CE is the control data information (byte 4).
set to program 480MHz /32 = 15MHz since the SL1714
provides a divide by 32 prescaler output rather than the VCO
carrier frequency.
using a 7.8125kHz phase comparator frequency. The mini-
mum step size is 7.8125KHz x 8 (RF prescaler inside SP5611)
x 32 (SL1714 output prescaler) = 2MHz.
phase comparator frequency), the minimum step size will be
1MHz.
CC and modifying the programmable divider information for
the new step size.
I2C Byte
Byte 1 (address)
Byte 2 (programmable divider 8 MSBs)
Byte 3 (programmable divider 8 LSBs)
Byte 4 (control data)
Byte 5 (port data)
A SP5611 synthesiser is used to set the frequency of the
C2 is the address byte (byte 1).
**Note - the programmable divider information should be
It is not possible to program the VCO to 479.5MHz when
If the reference divider is set to 1024 mode (3.90625kHz
This may be achieved by programming the control byte to
Hex Code
C2
00
F0
CE
00
SL1714 Operation
This is controlled as above via a SP5611 synthesiser.
IF input, and the signal mixed directly down to baseband.
the SL1714 which is deliberately offset from the VCO. By
varying the offset from 0-20MHz and monitoring the I and Q
channel baseband outputs, the flatness response of the chip/
output filter can be measured.
ON-VCO-OFF switch to the OFF position.
provided, together with a test point.
Measurement of Gain and Phase Match.
example above).
(0.707V p-p), in combination with the appropriate AGC
setting.
when using 50 inputs. When using high impedance probes,
the direct outputs may be used. Selection of outputs is via the
on board U links.
The calibration should be performed at the chosen baseband
frequency and level for maximum accuracy.
f) Vary the RF input frequency either side of the LO and note
the relative I and Q gain and phase reading.
further help, please contact Robert Marsh on 01793 518234
or Fred Herman on 01793 518423
a) Synthesise the required frequency (480MHz is used in the
b) Connect an RF signal generator to the input.
d) Connect a vector voltmeter to the BUFFERED outputs
e) CALIBRATE the vector voltmeter and the leads to be used.
c)Input a signal which should give an output of approx 0dBm
The SL1714 will mix an IF input with its own local oscillator.
Normally the VCO will be set to the same frequency as the
Alternatively, a CW RF source may be fed into the input of
The SL1714 oscillator may also be disabled by setting the
An AGC voltage adjust pot marked AGC ADJUST is
If you experience any difficulties with this board, or require
SL1714
13