ADF4207 datasheet(16/20 Pages) AD

16 / 20 page

REV. 0

ADF4206/ADF4207/ADF4208

–16–

PROGRAM MODES

Table III and Table V show how to set up the Program Modes

in the ADF420x family. The following should be noted:

1. RF2 and RF1 Analog Lock Detect indicate when the PLL

is in lock. When the loop is locked and either RF2 or RF1

Analog Lock Detect is selected, the MUXOUT pin will show a

logic high with narrow low-going pulses. When the RF2/RF1

Analog Lock Detect is chosen, the locked condition is indi-

cated only when both RF2 and RF1 loops are locked.

2. The RF2 Counter Reset mode resets the R and AB counters

in the RF2 section and also puts the RF2 charge pump into

three-state. The RF1 Counter Reset mode resets the R and AB

counters in the RF1 section and also puts the RF1 charge

pump into three-state. The RF2 and RF1 Counter Reset

mode does both of the above.

Upon removal of the reset bits, the AB counter resumes count-

ing in close alignment with the R counter (maximum error is

one prescaler output cycle).

3. The Fastlock mode uses MUXOUT to switch a second loop

ﬁlter damping resistor to ground during Fastlock operation.

Activation of Fastlock occurs whenever RF1 CP Gain in the

RF1 Reference counter is set to one.

POWER-DOWN

It is possible to program the ADF420x family for either syn-

chronous or asynchronous power-down on either the RF2 or

RF1 side.

Synchronous RF2 Power-Down

Programming a “1” to P7 of the ADF420x family will initiate a

power-down. If P2 of the ADF420x family has been set to “0”

(normal operation), a synchronous power-down is conducted.

The device will automatically put the charge pump into three-

state and then complete the power-down.

Asynchronous RF2 Power-Down

If P2 of the ADF420x family has been set to “1” (three-state

the RF2 charge pump), and P7 is subsequently set to “1,” an

asynchronous power-down is conducted. The device will go into

power-down on the rising edge of LE, which latches the “1” to

the RF2 power-down bit (P7).

Synchronous RF1 Power-Down

Programming a “1” to P16 of the ADF420x family will initiate

a power-down. If P10 of the ADF420x family has been set to

“0” (normal operation), a synchronous power-down is conducted.

The device will automatically put the charge pump into three-

state and then complete the power-down.

Asynchronous RF1 Power-Down

If P10 of the ADF420x family has been set to “1” (three-state

the RF1 charge pump), and P16 is subsequently set to “1,” an

asynchronous power-down is conducted. The device will go into

power-down on the rising edge of LE, which latches the “1” to

the RF1 power-down bit (P16).

Activation of either synchronous or asynchronous power-down

forces the RF2/RF1 loop’s R and N dividers to their load

state conditions and the RF2/RF1 input section is debiased to

a high impedance state.

The reference oscillator circuit is only disabled if both the RF2

and RF1 power-downs are set.

The input register and latches remain active and are capable of

loading and latching data during all the power-down modes.

The RF2/RF1 section of the devices will return to normal pow-

ered up operation immediately upon LE latching a “0” to the

appropriate power-down bit.

IF SECTION (RF2)

Programmable RF2 Reference (R) Counter

If control bits (C2, C1) are (0, 0), the data is transferred from

the input shift register to the 14-bit RF2 R counter. Table III

shows the input shift register data format for the RF2 R counter

and the divide ratios possible.

RF2 Phase Detector Polarity

P1 sets the RF2 Phase Detector Polarity. When the RF2 VCO

characteristics are positive, this should be set to “1.” When they

are negative, it should be set to “0.” See Table III.

RF2 Charge Pump Three-State

P2 puts the RF2 charge pump into three-state mode when pro-

grammed to a “1.” It should be set to “0” for normal operation.

See Table III.

RF2 Program Modes

Table III and Table V show how to set up the Program Modes

in the ADF420x family.

RF2 Charge Pump Currents

Bit P5 programs the current setting for the RF2 charge pump.

See Table III.

Programmable RF2 AB Counter

If control bits (C2, C1) are (0, 1), the data in the input register is

used to program the RF2 AB counter. The AB counter consists of

a 6-bit swallow counter (A counter) and 11-bit programmable

counter (B counter). Table IV shows the input register data

format for programming the RF2 AB counter and the divide

ratios possible.

RF2 Prescaler Value

P6 in the RF2 AB counter latch sets the RF2 prescaler value. See

Table IV.

RF2 Power-Down

P7 in Table IV is the power-down bit for the RF2 side.

OBSOLETE

ADF4207 Datasheet(PDF) 16 Page - Analog Devices

ADF4207 Datasheet(HTML) 16 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

Datasheet Download

Link URL