ADF5901

Data Sheet

Rev. A | Page 18 of 26

Figure 22. Register 3 (R3)

REGISTER 3

Control Bits

With Bits[C5:C1] set to 00011, Register R3 is programmed.

Figure 22 shows the input data format for programming this

register.

MUXOUT Control

Bits[DB15:DB12] control the on-chip multiplexer of the

ADF5901. See Figure 22 for the truth table.

Input/Output (IO) Level

Bit DB11 controls the DOUT logic levels. Setting this bit to 0 sets

the DOUT logic level to 1.8 V. Setting this bit to 1 sets the DOUT

logic level to 3.3 V.

Readback Control

Bits[DB10:DB5] control the readback data to DOUT on the

ADF5901. See Figure 22 for the truth table.

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

0

0

0

0

0

0

0

1

1

0

0

0

1

0

0

1

M3

M2

M1

M0

IOL

RC5

RC4 RC3 RC2 RC1 RC0

C4(0) C3(0) C2(1) C1(1)

CONTROL

BITS

RESERVED

C5(0)

READBACK CONTRO L

RC3 RC2 RC1 RC0

READBACK CONTRO L

0

0

0

0

NONE

0

0

0

1

REGISTER 0

0

0

1

0

REGISTER 1

0

0

1

1

REGISTER 2

0

1

0

0

REGISTER 3

0

1

0

1

REGISTER 4

0

1

1

0

REGSITER 5

0

1

1

1

REGISTER 6

1

0

0

0

REGISTER 7

1

0

0

1

REGISTER 8

1

0

1

0

REGISTER 9

1

0

1

1

REGISTER 10

1

1

0

0

REGISTER11

.

.

.

.

RESERVED

0

1

0

1

RESERVED

0

1

1

0

ADC READBACK

RC4

0

0

0

0

0

0

0

0

0

0

0

0

0

.

1

1

0

1

1

1

RESERVED

.

.

.

.

RESERVED

.

.

.

.

RESERVED

1

1

1

1

RESERVED

1

.

.

1

M3 M2

M1 M0

MUXOUT

0

0

0

0

TRISTATE OUTPUT

0

0

0

1

LOGIC HIGH

0

0

1

0

LOGIC LOW

0

0

1

1

R-DIVIDER OUTPUT

0

1

0

0

N-DIVIDER OUTPUT

0

1

0

1

RESERVED

0

1

1

0

RESERVED

0

1

1

1

CAL BUSY

1

0

0

0

RESERVED

1

0

0

1

RESERVED

1

0

1

0

RESERVED

1

0

1

1

R-DIVIDER/2

1

1

0

0

N-DIVIDER/2

1

1

0

1

RESERVED

1

1

1

0

RESERVED

1

1

1

1

RESERVED

RC5

0

0

0

0

0

0

0

0

0

0

0

0

0

.

0

0

0

.

.

1

IOL

0

1

IO LEVEL

3.3V LOGIC OUTPUTS

1.8V LOGIC OUTPUTS