SKY74038 Datasheet, PDF (10/12 Pages) Skyworks Solutions Inc. – 2.6 GHz/800 MHz Dual Fractional-N/lnteger-N Frequency Synthesizer

DATA SHEET • SKY74038 FREQUENCY SYNTHESIZER
Table 5. SKY74038 Register Descriptions (2 of 2)
Symbol
Function
Description
Register Word Address 10b
Address bits [1:0]
10b
SP2
IF synthesizer phase detector output polarity Bit [2] sets the IF synthesizer phase detector output:
[2]
0 = Set phase detector output for negative VCO gain
1 = Set phase detector output for positive VCO gain
EN
Enable mode [4:3]
Bits [4:3] enable the RF and/or IF synthesizers:
bit 4 bit 3
0 0 Enable both RF and IF synthesizers
0 1 Enable only RF synthesizer
1 0 Enable only IF synthesizer
1 1 Set power-down mode for both RF and IF synthesizers
N2
IF synthesizer main divider [21:5]
Bits [21:5] set the IF synthesizer 17-bit main divider ratio
Register Word Address 11b
Address bits [1:0]
11b
FN
RF synthesizer fractional-N division [9:2]
Bits [9:2] set the RF synthesizer’s fractional-N program up to 256 modulo
N1
RF synthesizer main divider [21:10]
Bits [21:10] set the RF synthesizer’s 12-bit main divider ratio with a 16/17 prescaler, or an
11-bit main divider ratio with 8/9 prescaler
Note 1: These bits must be programmed after power is applied to the device. Failure to do so may result in erroneous device operation.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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June 4, 2007 • Skyworks Proprietary and Confidential information • Products and Product Information are Subject to Change Without Notice • 101075M