ADF4356BCPZ datasheet(22/35 Pages) AD

22 / 35 page

ADF4356

Data Sheet

Rev. 0 | Page 22 of 35

Reference Mode

The ADF4356 permits use of either differential or single-ended

reference sources.

For optimum integer boundary spur performance, it is

recommended to use the single-ended setting for all references

up to 250 MHz (even if using a differential reference signal). Use

the differential setting for reference frequencies above 250 MHz.

Level Select

To assist with logic compatibility, MUXOUT is programmable to

two logic levels. Set the U5 bit (Bit DB8) to 0 to select 1.8 V

logic, and set it to 1 to select 3.3 V logic.

Phase Detector Polarity

The U4 bit (Bit DB7) sets the phase detector polarity. When a

passive loop filter or a noninverting active loop filter is used, set

DB7 to 1 (positive). If an active filter with an inverting

characteristic is used, set this bit to 0 (negative).

Power-Down

The U3 bit (Bit DB6) sets the programmable power-down mode.

Setting DB6 to 1 performs a power-down. Setting DB6 to 0 returns

the synthesizer to normal operation. In software power-down

mode, the ADF4356 retains all information in its registers. The

When power-down activates, the following events occur:

•

The synthesizer counters are forced to their load state

conditions.

•

The VCO powers down.

•

The charge pump is forced into three-state mode.

•

The digital lock detect circuitry resets.

•

The RFOUTA+/RFOUTA− and RFOUTB+/RFOUTB− output

stages are disabled.

•

The input registers remain active and capable of

loading and latching data.

Charge Pump Three-State

Setting the U2 bit (Bit DB5) to 1 puts the charge pump into

three-state mode. Set DB5 to 0 for normal operation.

Counter Reset

The U1 bit (Bit DB4) resets the R counter, N counter, and VCO

band select of the ADF4356. When DB4 is set to 1, the RF

synthesizer N counter, R counter, and VCO band select are reset.

For normal operation, set DB4 to 0.

The bits in Register 5 are reserved and must be programmed as

described in Figure 33, using a hexadecimal word of 0x00800025.

DB0

DB1

DB2

DB3

DB4

DB5

DB6

DB7

DB8

DB9

DB10

DB11

DB12

DB13

DB14

DB15

DB16

DB17

DB18

DB19

DB20

DB21

DB22

DB23

DB24

DB25

DB26

DB27

DB28

DB29

DB30

DB31

C1(1)

C2(0)

C3(1)

C4(0)

RESERVED

CONTROL

BITS

Figure 33. Register 5 (0x00800025)

ADF4356BCPZ датащи(PDF) 22 Page - Analog Devices

ADF4356BCPZ датащи(HTML) 22 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

датащи скачать

ссылки URL