SKY72301-22 Skyworks Solutions Inc, SKY72301-22 Datasheet - Page 9

• Manufacturer Part Number: SKY72301-22
• Description: IC SYNTHESIZER 1GHZ 28-EPTSSOP
• Manufacturer: Skyworks Solutions Inc
• Type: Fractional N Synthesizerr

Specifications of SKY72301-22

• Pll: Yes
• Input: Clock, Crystal
• Output: Clock, Crystal
• Number Of Circuits: 1
• Ratio - Input:output: 2:2
• Differential - Input:output: Yes/Yes
• Frequency - Max: 1GHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 2.7 V ~ 3.3 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP Exposed Pad, 28-eTSSOP, 28-HTSSOP
• Frequency-max: 1GHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 863-1078-2

Table 1. SKY72301-22 Register Map
When the sum of the dividend and modulation data lie outside this
range, the value of N
For a more detailed description of direct digital modulation
functionality, refer to the Skyworks Application Note, Direct Digital
Modulation Using the SKY72300, SKY72301-22, and SKY72302
Dual Synthesizers/PLLs (document number 101349).
Register Descriptions
Table 1 lists the 10 16-bit registes that are used to program the
SKY72301-22. All register writes are programmed address first,
followed directly with data. MSBs are entered first. On power-up,
all registers are reset to 0x000 except registers at address 0x0
and 0x3, which are set to 0x006.
Main Synthesizer Registers
The Main Divider Register contains the integer portion closest to
the desired fractional-N (or the integer-N) value minus 32 for the
main synthesizer. This register, in conjunction with the Main
Dividend MSB/LSB registers (which control the fraction offset
from –0.5 to +0.5), allows selection of a precise frequency. As
shown in Figure 6, the value to be loaded is:
The Main Dividend MSB/LSB Registers control the fraction part of
the desired fractional-N value and allow an offset of –0.5 to + 0.5
to the main integer selected through the Main Divider Register. As
shown in Figures 7 and 8, values to be loaded are:
Note 1: All registers are write only.
Note 2: No address bits are required for modulation data. Any serial data between 2 and 12 bits long is considered modulation data.
Main Synthesizer Divider Index = Nine-bit value for the integer
portion of the main synthesizer dividers. Valid values for this
register are from 6 to 505 (fractional-N) or 0 to 511 (integer-N).
Address (Hex)
—
0
1
2
3
4
5
6
7
8
9
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
200706C • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 11, 2009
integer
Main Divider Register
Main Dividend MSB Register
Main Dividend LSB Register
Auxiliary Divider Register
Auxiliary Dividend Register
Reference Frequency Dividers Register
Phase Detector/Charge Pumps Control Register
Power Down/Multiplexer Output Select Control Register
Modulation Control Register
Modulation Data Register
Modulation Data Register (Note 2) — direct input
must be changed.
Register (Note 1)
The Main Dividend MSB/LSB Register values are 2's complement
format.
NOTE
Auxiliary Synthesizer Registers
The Auxiliary Divider Register contains the integer portion closest
to the desired fractional-N (or integer-N) value minus 32 for the
auxiliary synthesizer. This register, in conjunction with the
Auxiliary Dividend Register (which controls the fraction offset from
–0.5 to + 0.5) allows selection of a precise frequency. As shown
in Figure 9, the value to be loaded is:
The Auxiliary Dividend Register controls the fraction part of the
desired fractional-N value and allows an offset of –0.5 to + 0.5 to
the auxiliary integer selected through the Auxiliary Divider
Register. As shown in Figure 10, the value to be loaded is:
Main Synthesizer Dividend (MSBs) = Ten-bit value for the MSBs
of the 18-bit dividend for the main synthesizer.
Main Synthesizer Dividend (LSBs) = Eight-bit value for the LSBs
of the 18-bit dividend for the main synthesizer.
Auxiliary Synthesizer Divider Index = Nine-bit value for the
integer portion of the auxiliary synthesizer dividers. Valid values
for this register are from 6 to 505 (fractional-N) or from 0 to 511
(integer-N).
Auxiliary Synthesizer Dividend = Ten-bit value for the auxiliary
synthesizer dividend.
:
When in 10-bit mode, the Main Dividend LSB Register is
not required.
DATA SHEET • SKY72301-22 FREQUENCY SYNTHESIZER
2 length 12 bits
Length (Bits)
12
12
12
12
12
12
12
12
12
12
Address (Bits)
4
4
4
4
4
4
4
4
4
4
0
9