Data Sheet

ADF4355-2

Rev. B | Page 21 of 37

M14

M13

..........

M2

M1

MODULUS VALUE (MOD2)

0

0

..........

0

0

NOT ALLOWED

0

0

..........

0

1

NOT ALLOWED

0

0

..........

1

0

2

0

0

..........

1

1

3

.

.

..........

.

.

.

.

.

..........

.

.

.

.

.

..........

.

.

.

1

1

..........

0

0

16380

1

1

..........

0

1

16381

1

1

..........

1

0

16382

1

1

.........

1

1

16383

DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9

DB8

DB7

DB6

DB5

DB4 DB3

DB2

DB1

DB0

14-BIT AUXILIARY MODULUS VALUE (MOD2)

CONTROL

BITS

M14

M13

M12

M11

M10

M9M8M7M6M5M4M3M2

M1

C3(0) C2(1) C1(0)

C4(0)

F14

F13

..........

F2

F1

FRAC2 WORD

0

0

..........

0

0

0

0

0

..........

0

1

1

0

0

..........

1

0

2

0

0

..........

1

1

3

.

.

..........

.

.

.

.

.

..........

.

.

.

.

.

..........

.

.

.

1

1

..........

0

0

16381

1

1

..........

0

1

16382

1

1

..........

1

0

16382

1

1

.........

1

1

16383

F11

F10

F9

F8

F7

F6

F5

F4

F3

F2

F1

F12

F13

F14

14-BIT AUXILIARY FRACTIONAL VALUE (FRAC2)

Figure 32. Register 2

REGISTER 2

Control Bits

With Bits[C4:C1] set to 0010, Register 2 is programmed. Figure 32

shows the input data format for programming this register.

14-Bit Auxiliary Fractional Value (FRAC2)

The 14-bit auxiliary fractional value (Bits[DB31:DB18]) controls

the auxiliary fractional word. FRAC2 must be less than the

MOD2 value programmed in Register 2.

14-Bit Auxiliary Modulus Value (MOD2)

The 14-bit auxiliary modulus value (Bits[DB17:DB4]) sets the

auxiliary fractional modulus. Use MOD2 to correct any residual

error due to the main fractional modulus.