74HCT9046AD NXP Semiconductors, 74HCT9046AD Datasheet - Page 9

• Manufacturer Part Number: 74HCT9046AD
• Description: Phase Locked Loops (PLL) PHASE LOCKED LOOP W/VCO
• Manufacturer: NXP Semiconductors
• Type: PLLr

Specifications of 74HCT9046AD

• Number Of Circuits: 1
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 5 V
• Package / Case: SOIC-16
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 74HCT9046AD,112

NXP Semiconductors
74HCT9046A_6
Product data sheet
8.3.2 Phase Comparator 2 (PC2)
This is a positive edge-triggered phase and frequency detector. When the PLL is using
this comparator, the loop is controlled by positive signal transitions and the duty cycles of
SIG_IN and COMP_IN are not important. PC2 comprises two D-type flip-flops, control
gating and a 3-state output stage with sink and source transistors acting as current
sources, henceforth called charge pump output of PC2. The circuit functions as an
up-down counter (see
count. The current switch charge pump output allows a virtually ideal performance of PC2,
due to appliance of some pulse overlap of the up and down signals, see
The pump current I
band gap reference of 2.5 V.
Where R
The current and voltage transfer function of PC2 are shown in
The phase comparator gain is:
I
K
cp
Fig 7.
P
=
=
17
--------- - A r
I
2
cp
bias
Typical waveforms for PLL using phase comparator 1; loop-locked at f
----------- - A
R
2.5
bias
is the external bias resistor between pin RB and ground.
cp
Rev. 06 — 15 September 2009
VCO_OUT
PC1_OUT
is independent from the supply voltage and is set by the internal
COMP_IN
VCO_IN
Figure
SIGN_IN
V
V
C1A
C1B
4) where SIG_IN causes an up-count and COMP_IN a down
PLL with band gap controlled VCO
74HCT9046A
Figure
mbd100
GND
V
C1A
C1B
CC
9.
© NXP B.V. 2009. All rights reserved.
Figure
0
8a.
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