DATA SHEET • CX72301

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

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July 21, 2004 • Skyworks Proprietary and Confidential information • Products and Product Information are Subject to Change Without Notice • 101090H

• Auxiliary Synthesizer Power Down = 1-bit value that powers

down the auxiliary synthesizer. When this bit is 0, the auxiliary

synthesizer is powered up. When this bit is 1, the auxiliary

synthesizer is in power-down mode.

• Auxiliary Synthesizer mode = 1-bit value that powers down the

auxiliary synthesizer’s

∆Σ modulator and fractional unit to

operate as an integer-N synthesizer. When this bit is 0, the

auxiliary synthesizer is in fractional-N mode. When this bit is 1,

the auxiliary synthesizer is in integer-N mode.

NOTE: There are no special power-up sequences required for

the CX72301.

• Multiplexer Output Selection = 3-bit value that selects which

internal signal is output to the Mux_out pin. Internal signals

available on this pin are the following:

− Reference Oscillator, F

ref

− Main or auxiliary divided reference (post reference

− Main or auxiliary phase detector frequency (post main and

− Serial data out, for loop-back and test purposes

See Table 4 for more information.

• Mux_out Pin Three-State Enable = 1-bit value to three-state the

Mux_out pin. When this bit is 0, the Mux_out pin is enabled.

When this bit is 1, the Mux_out pin is three-stated.

A3

A2 A1

A0 11

10

9

8

7

6

5

4

3

2

1

0

01

11

X

X

MSB

LSB

Full Power Down

Main Synthesizer Power Down

Main Synthesizer Mode

Main Synthesizer

∆Σ Fractionality

Auxiliary Synthesizer Power Down

Auxiliary Synthesizer Mode

Multiplexer Output Selection

Mux_out Pin Three-State Enable

C1424

Figure 13. Power Down and Multiplexer Output Register (Write Only)

Table 4. Multiplexer Output

Multiplexer Output Select

(Bit 8)

Multiplexer Output Select

(Bit 7)

Multiplexer Output Select

(Bit 6)

Multiplexer Output

(Mux_out)

0

0

0

Reference Oscillator

0

0

1

0

1

0

0

1

1

1

0

0

1

0

1

Serial data out

1

1

0

Serial Interface Register test output