Preliminary Technical Data

ADF7021

Rev. PrI | Page 33 of 44

REGISTER 5—IF FILTER SETUP REGISTER

IR PHASE

ADJUST MAG

IR GAIN

ADJUST MAG

IF FILTER DIVIDER

IF FILTER ADJUST

ADDRESS

BITS

CC1

0

1

CAL

NO CAL

DO CAL

PD1

0

1

IR PHASE ADJUST I/Q

ADJUST I CH

ADJUST Q CH

GA1

0

1

IR GAIN ADJUST UP/DN

GAIN

ATTENUATE

GQ1

0

1

IR GAIN ADJUST I/Q

ADJUST I CH

ADJUST Q CH

IFD3

0

0

.

.

.

.

1

IFD1

1

0

.

.

.

.

1

FILTER CLOCK

DIVIDE RATIO

1

2

.

.

.

.

511

IFD2

0

1

.

.

.

.

1

IFA2

0

0

1

.

1

0

0

1

.

1

IF FILTER

ADJUST

IFA6

0

0

0

.

0

1

1

1

1

1

GM3

IR GAIN

ADJUST

GM5

0

0

0

.

1

IFD9

0

0

.

.

.

.

1

IFD6

0

0

.

.

.

.

1

.

.

.

.

.

.

.

.

IFD5

0

0

.

.

.

.

1

IFD4

0

0

.

.

.

.

1

0

1

0

.

1

0

1

0

.

1

IFA1

...

...

...

...

...

...

...

...

...

...

...

0

× 300Hz

–1 × 300Hz

–2 × 300Hz

...

–31 × 300Hz

0 × 300Hz

1 × 300Hz

2 × 300Hz

...

31 × 300Hz

GM4

GM2 GM1

0

0

0

.

1

0

0

0

.

1

0

0

1

.

1

0

1

0

.

1

0

1

2

...

31

PM2

IR PHASE

ADJUST

PM3

PM1 PM1

0

0

0

.

1

0

0

0

.

1

0

0

1

.

1

0

1

0

.

1

0

1

2

...

31

Figure 37.

Register 5—IF Filter Setup Register Comments

•

A coarse IF filter calibration is performed when the Coarse Cal Bit (R5_DB4) is set. If the Fine Cal Bit (R6_DB4) in is set, a fine IF

filter calibration is performed after the coarse calibration.

•

Set IF_Filter_DIVIDE such that

kHz

50

_

_

=

DIVIDE

FILTER

IF

XTAL

•

IF_FILTER_ADJUST allows the IF filter response to be manually adjusted in 300 Hz steps.