Datasheet

ADF4193 Data Sheet
Rev. F | Page 20 of 32
POWER-DOWN REGISTER (R5)
05328-028
DB7
F5
DB6
F4
DB5
F3
DB4
F2
DB3
F1
DB2
C3 (1)
DB1
C2 (0)
DB0
C1 (1)
COUNTER
RESET
CP
3-STATE
PD
CHARGE
PUMP
CONTROL
BITS
PD
DIFF AMP
0
1
F4
0
1
F5
DISABLED
ENABLED
DIFF AMP
POWER-DOWN
0
1
F2
NORMAL OPERATION
3-STATE ENABLED
CHARGE PUMP
3-STATE
0
1
F1
NORMAL OPERATION
COUNTER RESET
COUNTER RESET
0
1
F3
DISABLED
ENABLED
CHARGE PUMP
POWER-DOWN
Figure 34. Power-Down Register (R5)
R5, the power-down register (C3, C2, C1 set to 1, 0, 1, respectively)
can be used to software power down the PLL and differential
amplifier sections. After power is initially applied, there must be
writes to R5 to clear the power-down bits and to R2, R1, and R0
before the ADF4193 comes out of power-down.
Power-Down Differential Amplifier
When Bit DB6 and Bit DB7 are set high, the differential
amplifier is put into power-down. When Bit DB6 and Bit DB7
are set low, normal operation is resumed.
Power-Down Charge Pump
Setting Bit DB5 high activates a charge pump power-down and
the following events occur:
• All active dc current paths are removed, except for the
differential amplifier.
• The R and N divider counters are forced to their load state
conditions.
• The charge pump is powered down with its outputs in three-
state mode.
• The digital lock detect circuitry is reset.
• The RF
IN
input is debiased.
• The reference input buffer circuitry is disabled.
• The serial interface remains active and capable of loading and
latching data.
For normal operation, Bit DB5 should be set to 0, followed by a
write to R0.
CP Three-State
When this bit is set high, the charge pump outputs are put into
three-state. With the bit set low, the charge pump outputs are
enabled.
Counter Reset
When this bit is set to 1, the counters are held in reset. For normal
operation, this bit should be 0, followed by a write to R0.