74hct7046a NXP Semiconductors, 74hct7046a Datasheet - Page 37

• Manufacturer Part Number: 74hct7046a
• Description: Phase-locked-loop With Lock Detector
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Note
For an extensive description and application example please refer to application note ordering number
9398 649 90011.
Also available a computer design program for PLL’s ordering number 9398 961 10061.
Since the output frequency is proportional to the VCO control voltage, the PLL frequency response can be observed with
an oscilloscope by monitoring pin 9 of the VCO. The average frequency response, as calculated by the Laplace method,
is found experimentally by smoothing this voltage at pin 9 with a simple RC filter, whose time constant is long compared
to the phase detector sampling rate but short compared to the PLL response time.
December 1990
Phase-locked-loop with lock detector
e
e
/
(t)
n
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
Fig.35 Type 1, second order frequency step response.
= 5.0
1
Fig.34 Frequency synthesizer.
2
= 2.0
3
37
4
= 0.3
0.5
0.707
1.0
5
6
7
MGA959
n t
8
0
0.2
0.4
0.6
0.8
1.0
74HC/HCT7046A
0.6
0.4
0.2
e
e
/
(t)
Product specification
n