SKY72301-22 Skyworks Solutions Inc, SKY72301-22 Datasheet - Page 7

• 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

Case 2: To achieve a desired F
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
of the synthesizer in 10-bit mode. Since the maximum internal reference frequency (F
frequency does not require the internal division to be greater than 1, which makes F
The value to be programmed in the Main Divider Register is:
With the modulator in 10-bit mode, the value to be programmed in the Main Dividend Registers is:
where 11 0011 0100 is loaded in the MSB of the Main Dividend Register.
Summary:
· · Main Divider Register = 0 0001 0000
· · Main Dividend Register, MSB = 11 0011 0100
· · The resulting main VCO frequency is 917.775 MHz
· · Step size is 18.75 kHz
Note: The frequency step size for this case is 19.2 MHz divided by 2
N
N
dividend = Round[divider × (N
fractional
reg
= Round[N
= Round[47.80087] – 32
= 48 – 32
= 16 (decimal)
= 000010000 (binary)
= Round[1024 × (47.80087 – 16 – 32)]
= Round[1024× (–0.1990312)]
= Round[–203.808]
= 204 (decimal)
= 1100110100 (binary)
Figure 4. Fractional-N Applications: Sample Calculation (2 of 2)
= F
= 917.7786
= 47.80097
vco_main
vco_main
F
fractional
div_ref
19.2
frequency of 917.7786 MHz using a crystal frequency of 19.2 MHz with operation
] – 32
fractional
– N
reg
– 32)]
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DATA SHEET • SKY72301-22 FREQUENCY SYNTHESIZER
, giving 18.75 kHz.
div_ref
div_ref
= 19.2 MHz. Therefore:
) is 25 MHz, the crystal
C1415
7