DATA SHEET • CX74038

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

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January 31, 2005 • Skyworks Proprietary and Confidential information • Products and product information are subject to change without notice • 101075I

Table 5. CX74038 Register Descriptions (2 of 2)

Symbol

Function

Description

Register Word Address 10

Address bits [1:0]

10

SP2

IF synthesizer phase detector output polarity

[2]

Bit [2] sets the IF synthesizer phase detector output:

0 Sets phase detector output for negative VCO gain

1 Sets 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

Enables both RF SX and IF SX

0

1

Enables only RF SX

1

0

Enables only IF SX

1

1

Sets power-down mode for both RF/IF SX

N2

IF synthesizer main divider [21:5]

Bits [21:5] set the IF synthesizer 17-bit main divider ratio

Register Word Address 11

Address bits [1:0]

11

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.