Data Sheet

ADF4159

Rev. B | Page 19 of 36

Charge Pump Three-State

When Bit DB4 is set to 1, the charge pump is placed into three-

state mode. For normal charge pump operation, set this bit to 0.

Counter Reset

Bit DB3 is the RF counter reset bit. When this bit is set to 1, the

RF synthesizer counters are held in reset. For normal operation,

set this bit to 0.

DB31

RESERVED

CONTROL

BITS

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

NB3

NB2

NB1

0

0

0

0

1

L1

NS1

U12

0

0

RM2 RM1

0

0

U11

U10

U9

U8

U7

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

U9

POWER-DOWN

0

DISABLED

1

ENABLED

U10

PD POLARITY

0

NEGATIVE

1

POSITIVE

U11

LDP

0

14ns

1

6ns

NS1

N SEL

0

N WORD LOAD ON Σ-Δ CLOCK

1

N WORD LOAD DELAYED 4 CYCLES

RM2

RAMP MODE

0

CONTINUOUS SAWTOOTH

1

RM1

0

1

SINGLE RAMP BURST

1

0

SINGLE SAWTOOTH BURST

0

1

CONTINUOUS TRIANGULAR

NB2

NEGATIVE BLEED CURRENT (µA)

0

3.73

11.03

25.25

53.1

109.7

224.7

454.7

916.4

1

NB1

0

1

1

0

0

NB3

0

0

1

1

1

1

0

1

0

1

1

0

0

1

0

0

1

U7

COUNTER

RESET

0

DISABLED

1

ENABLED

U8

CP

THREE-STATE

0

DISABLED

1

ENABLED

RESERVED

NEG BLEED

CURRENT

U12

Σ-Δ RESET

0

ENABLED

1

DISABLED

L1

LOL

0

ENABLED

1

DISABLED

0

NEG BLEED EN

0

DISABLED

1

ENABLED

0

FSK

0

DISABLED

1

ENABLED

0

PSK

0

DISABLED

1

ENABLED

Figure 28. Function Register (R3) Map