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MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Phase Locked Loop
The MC14046B phase locked loop contains two phase comparators, a
voltage–controlled oscillator (VCO), source follower, and zener diode. The
comparators have two common signal inputs, PCA in and PCB in . Input PCA in
can be used directly coupled to large voltage signals, or indirectly coupled
(with a series capacitor) to small voltage signals. The self–bias circuit
adjusts small voltage signals in the linear region of the amplifier. Phase
comparator 1 (an exclusive OR gate) provides a digital error signal PC1 out ,
and maintains 90 phase shift at the center frequency between PCA in and
PCB in signals (both at 50% duty cycle). Phase comparator 2 (with leading
edge sensing logic) provides digital error signals, PC2 out and LD, and
maintains a 0 phase shift between PCA in and PCB in signals (duty cycle is
immaterial). The linear VCO produces an output signal VCO out whose
frequency is determined by the voltage of input VCO in and the capacitor and
resistors connected to pins C1 A , C1 B , R1, and R2. The source–follower
output SF out with an external resistor is used where the VCO in signal is
needed but no loading can be tolerated. The inhibit input Inh, when high,
disables the VCO and source follower to minimize standby power
consumption. The zener diode can be used to assist in power supply
regulation.
Applications include FM and FSK modulation and demodulation, fre-
quency synthesis and multiplication, frequency discrimination, tone decod-
ing, data synchronization and conditioning, voltage–to–frequency
conversion and motor speed control.
Buffered Outputs Compatible with MHTL and Low–Power TTL
Diode Protection on All Inputs
Supply Voltage Range = 3.0 to 18 V
Pin–for–Pin Replacement for CD4046B
Phase Comparator 1 is an Exclusive Or Gate and is Duty Cycle Limited
Phase Comparator 2 switches on Rising Edges and is not Duty Cycle
Limited
SELF BIAS
PCA in
14
CIRCUIT
PCB in
3
VCO in
9
V DD = PIN 16
V SS = PIN 8
INH
5
V SS
MC14046B
6–120
BLOCK DIAGRAM
PHASE
COMPARATOR 1
PHASE
COMPARATOR 2
VOLTAGE
CONTROLLED
OSCILLATOR
(VCO)
SOURCE FOLLOWER
MC14046B
ORDERING INFORMATION
MC14XXXBCP
MC14XXXBCL
MC14XXXBDW
T A = – 55 to 125 C for all packages.
PC1 out
PCB in
VCO out
2 PC1 out
13 PC2 out
1 LD
4 VCO out
11 R1
12 R2
6 C1 A
7 C1 B
10 SF out
15 ZENER
MOTOROLA CMOS LOGIC DATA
L SUFFIX
CERAMIC
CASE 620
P SUFFIX
PLASTIC
CASE 648
DW SUFFIX
SOIC
CASE 751G
Plastic
Ceramic
SOIC
PIN ASSIGNMENT
LD
1
16
V DD
2
15
ZENER
3
14
PCA in
4
13
PC2 out
INH
5
12
R2
C1 A
6
11
R1
C1 B
7
10
SF out
V SS
8
9
VCO in
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