SKY72310 Datasheet, PDF (10/19 Pages) List of Unclassifed Manufacturers – SKY72310: Spur-Free, 2.1 GHz Single Fractional-N Frequency Synthesizer

DATA SHEET • SKY72310 FREQUENCY SYNTHESIZER
A3 A2 A1 A0 11 10 9 8 7 6 5 4 3 2 1 0
0 10 1X X
Reference Frequency Divider Index
S1064
Figure 8. Reference Frequency Dividers Register (Write Only)
A3 A2 A1 A0 11 10 9 8 7 6 5 4 3 2 1 0
0 11 0
Phase Detector Gain
Power Steering/Lock Detect Enable
S1065
Figure 9. Phase Detector/Charge Pump Control Register (Write Only)
A3 A2 A1 A0 11 10 9 8 7 6 5 4 3 2 1 0
0111X X
MSB
LSB
Full Power Down
Synthesizer Power Down
Synthesizer Mode
Synthesizer ΔΣ Fractionality
Multiplexer Output Selection
Mux_out Pin Three-State Enable
S1066
Figure 10. Power Down/Multiplexer Output Select Control Register (Write Only)
The Phase Detector/Charge Pump Control Register allows control
of the gain for the phase detector and configuration of the
LD/PSmain signal (pin 4) for frequency power steering or lock
detection. As shown in Figure 9, the values to be loaded are:
• Phase Detector Gain = Five-bit value for programmable phase
detector gain. Range is from 0 to 31 decimal for 31.25 to 1000
µA/ 2π radian, respectively.
• Power Steering Enable = One-bit flag to enable the frequency
power steering circuitry of the phase detector. When this bit is
cleared, the LD/PSmain pin is configured to be a lock detect,
active low, open collector pin. When this bit is set, the
LD/PSmain pin is configured to be a frequency power steering
pin and can be used to bypass the external loop filter to provide
faster frequency acquisition.
The Power Down/Multiplexer Output Select Control Register
allows control of the power-down modes, internal multiplexer
output, and ∆Σ synthesizer fractionality. As shown in Figure 10,
the values to be loaded are:
• Full Power Down = One-bit flag to power down the SKY72310
except for the reference oscillator and the serial interface. When
this bit is cleared, the SKY72310 is powered up. When this bit is
set, the SKY72310 is in full power-down mode excluding the
Mux_out signal (pin 24).
• Synthesizer Power Down = One-bit flag to power down the
synthesizer. When this bit is cleared, the synthesizer is powered
up. When this bit is set, the synthesizer is in power-down mode.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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July 30, 2008 • Skyworks Proprietary and Confidential information • Products and Product Information are Subject to Change Without Notice • 200705E