SP5730 Datasheet, PDF (4/12 Pages) Mitel Networks Corporation – 1.3GHz Low Phase Noise Frequency Synthesiser

SP5730 Datasheet
Table 2 - Reference division ratios
R4 R3 R2 R1 R0 Division ratio
00 0 0 0
00 0 0 1
00 0 1 0
00 0 1 1
00 1 0 0
00 1 0 1
00 1 1 0
00 1 1 1
01 0 0 0
01 0 0 1
01 0 1 0
01 0 1 1
01 1 0 0
01 1 0 1
01 1 1 0
01 1 1 1
10 0 0 0
10 0 0 1
10 0 1 0
10 0 1 1
10 1 0 0
10 1 0 1
10 1 1 0
10 1 1 1
11 0 0 0
11 0 0 1
11 0 1 0
11 0 1 1
11 1 0 0
11 1 0 1
11 1 1 0
11 1 1 1
2
4
8
16
32
64
128
256
Illegal state
5
10
20
40
80
160
320
Illegal state
6
12
24
48
96
192
384
Illegal state
7
14
28
56
112
224
448
Write mode
With reference to Table 3, bytes 2 and 3 contain frequency
information bits 2¹⁴-2⁰ inclusive. Bytes 4 and 5 control
the reference divider ratio (see Table 2), charge pump
setting (see Table 7), REF/COMP output (see Table 8),
output ports and test modes (see Table 6).
After reception and acknowledgement of a correct
address (byte 1), the first bit of the following byte
determines whether the byte is interpreted as a byte 2 or
4, a logic ‘0’ indicating byte 2, and a logic ‘1’ indicating
byte 4. Having interpreted this byte as either byte 2 or 4,
the following data byte will be interpreted as byte 3 or 5
respectively. Having received two complete data bytes,
additional data bytes can be entered, where byte
interpretation follows the same procedure, without re-
addressing the device. This procedure continues until a
STOP condition is received. The STOP condition can be
generated after any data byte; if, however, it occurs during
a byte transmission, the previous byte data is retained.
To facilitate smooth fine tuning, the frequency data bytes
are only accepted by the device after all 15 bits of
frequency data have been received, or after the generation
of a STOP condition.
Read mode
When the device is in read mode, the status byte read
from the device takes the form shown in Table 4.
Bit 1 (POR) is the power-on reset indicator, and this is set
to a logic ‘1’ if the V_CC supply to the device has dropped
below 3V (at 25°C ), e.g. when the device is initially turned
on. The POR is reset to ‘0’ when the read sequence is
terminated by a STOP command. When POR is set high
this indicates the programmed information may be
corrupted and the device reset to power up condition.
Bit 2 (FL) indicates whether the device is phase locked, a
logic’1’is present if the device is locked, and a logic ‘0’ if it
is not.
Programable features
• RF programmable divider Function as described
above.
• Reference programmable divider Function as
described above.
• Charge pump current The charge pump current can
be programmed by bits C1 and C0 within data byte 5,
as defined in Table 7.
• Test mode The test modes are invoked by setting bits
RE, RS, T1 and T0 as described in Table 6.
• Reference/Comparison frequency output The
reference frequency f_REF or comparison frequency
f_COMP can be switched to the REF/COMP output,
function as defined in Table 8. RE and RS default to
logic’1’during device power up, thus enabling the
comparison frequency f_COMP at the REF/COMP output.
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