ADRF6801

Rev. 0 | Page 19 of 36

Register 5—LO Path and Demodulator Control

Register 5 controls whether the LOIP and LOIN pins act as an input or output, whether the divider before the polyphase divider is in

divide-by-1 or divide-by-2, and whether the demodulator bias circuitry is enabled as detailed in Figure 38.

DEMOD

BIAS

ENABLE

LO

FIRST

DIVIDER

LO

IN/OUT

CTRL

LO

OUTPUT

DRIVER

ENABLE

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8

DB7

DMBE

DB6

DB5

DB4

DB3

DB2

DB1

DB0

0

0

0

0

0

LDIV

LXL

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

LDRV

0

1

LXL

0

1

LDIV

0

1

÷ 1

÷ 2 (DEFAULT,

NECESSARY FOR VCO USE)

LO OUTPUT DRIVER

ENABLE

DRIVER OFF (DEFAULT)

DRIVER ON

DMBE

0

1

DISABLE

ENABLE (DEFAULT)

DEMOD BIAS ENABLE

LO IN/OUT CONTROL

LO OUTPUT (DEFAULT)

LO INPUT

DIVIDE RATIO

CONTROL BITS

0

0

000

00

0

00

0

0

Figure 38. LO Path and Demodulator Control Register (R5)