PE3240EK PEREGRINE [Peregrine Semiconductor Corp.], PE3240EK Datasheet - Page 10

• Manufacturer Part Number: PE3240EK
• Manufacturer: PEREGRINE [Peregrine Semiconductor Corp.]

Enhancement Register
The functions of the enhancement register bits are shown below with all bits active “high”.
Table 9. Enhancement Register Bit Functionality
Phase Detector
The phase detector is triggered by rising edges
from the main Counter (f
counter (f
and PD_D. If the divided VCO leads the divided
reference in phase or frequency (f
PD_D pulses “low”. If the divided reference leads
the divided VCO in phase or frequency (f
f
is directly proportional to phase offset between the
two input signals, f
The phase detector gain is equal to 2.70 V / 2 п,
which numerically yields 0.43 V / Radian.
©2006 Peregrine Semiconductor Corp. All rights reserved.
Page 10 of 12
p
** Program to 0
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
), PD_U pulses “low”. The width of either pulse
Bit Function
MSEL output
Counter load
Power down
c
Reserved**
Reserved**
Reserved**
). It has two outputs, namely PD_U,
f
f
p
c
output
output
p
and f
Drives the M counter output onto the Dout output.
Power down of all functions except programming interface.
Immediate and continuous load of counter programming.
Drives the internal dual modulus prescaler modulus select (MSEL) onto the Dout output.
Drives the reference counter output onto the Dout output
p
c
) and the reference
.
p
leads f
c
c
leads
),
Description
PD_U and PD_D drive an active loop filter which
controls the VCO tune voltage. PD_U pulses
result in an increase in VCO frequency and PD_D
results in a decrease in VCO frequency, for a
positive Kv VCO.
A lock detect output, LD is also provided, via the
pin Cext. Cext is the logical “NAND” of PD_U and
PD_D waveforms, which is driven through a series
2 kohm resistor. Connecting Cext to an external
shunt capacitor provides low pass filtering of this
signal. Cext also drives the input of an internal
inverting comparator with an open drain output.
Thus LD is an “AND” function of PD_U and PD_D
Document No. 70-0034-02 │ UltraCMOS™ RFIC Solutions
Product Specification
PE3240