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Part: MC44144D
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MC44144 Subcarrier Phase-Locked Loop
The MC44144 is a gated phaselocked loop intended for, but not restricted to, video applications. The integrated circuit contains a gated phase detector, voltage controlled crystal oscillator, divideby4 circuitry, and a video clamp. This device provides a 4X reference frequency output, and a 1X reference frequency output. The MC44144 is manufactured using Motorola's high density, bipolar MOSAICTM process. · 8Pin DIP or Surface Mount Package
SUBCARRIER PHASELOCKED LOOP
SEMICONDUCTOR TECHNICAL DATA
· · · ·
GatedPhase Detector Single Pin Voltage Controlled Crystal Oscillator 1X and 4X Subcarrier Output Operates Off of a Standard 5.0 V Supply
8 1
P SUFFIX PLASTIC PACKAGE CASE 626
8 1
D SUFFIX PLASTIC PACKAGE CASE 751 (SO8)
Representative Block Diagram
Composite Video 75 0.1µ 8 7 6 Video In Clamp In Reference Subcarrier Phase Detector 3 Phase Detector Output 4X Sub Xtal 5 4X Subcarrier Output 1.0n 1 Subcarrier Output VCC 8
+ 5.0
Burst Gate
PIN CONNECTIONS
Voltage Reference 2.6V
Clamp Out Gate Pulse Video Clamp
2
Gnd
Burst Gate Comp Video Input 4X Subcarrier Output
7
Phase Det Out
6
Subcarrier Reference Output 1 1.0n Subcarrier Output
Divide by 4
Voltage 4X Ref Control Out Input VCO 4X Ref Crystal Drive 2 3 4 14.32/ 17.73MHz 47k 470p 0.1µ 5.0 to 25p Device
4
5
(Top View)
ORDERING INFORMATION
Operating Temperature Range TA = 0° to +70°C Package SO8 Plastic
MC44144D MC44144P
© Motorola, Inc. 1996
Rev 2
MOTOROLA ANALOG IC DEVICE DATA
1
MC44144
ABSOLUTE MAXIMUM RATINGS
Rating Supply Voltage Operating Ambient Temperature Storage Temperature Range Operating Junction Temperature Symbol VCC TA Tstg TJ Value 6.0 0° to +70 65 to +150 +150 Unit Vdc °C °C °C
RECOMMENDED OPERATING CONDITIONS
Characteristic Supply Voltage Composite Video Input (Note 1) Burst Amplitude to Acquire Lock Pin 8 6 50 300 1000 Symbol VCC Min 4.5 Typ 5.0 Max 5.5 Unit Vdc mVpp
NOTE: 1. Total peaktopeak voltage of video should not exceed ground or VCC.
ELECTRICAL CHARACTERISTICS (VCC = 5.0 Vdc, TA = 25°C)
Characteristic Operating Current Burst Gate Threshold Voltage: Burst Gate Input Current: VIH VIL IIH (Vin = 5.0 V) IIL (Vin = 0 V) Pin 8 7 Min 8.0 3.0 400 200 Typ 10 610 450 25 300 200 60 3.0 3 ± 350 ± 500 Max 12 1.5 20 0.5 650 400 Unit mA Vdc µA
4X Subcarrier Output Voltage: (14.32 MHz) Output Voltage: (17.73 MHz) Output Impedance: (14.3 MHz and 17.73 MHz) Subcarrier Output Output Voltage: (3.58 MHz and 4.43 MHz) Output Impedance: (3.58 MHz and 4.43 MHz) Phase Angle (Note 1) Phase Sensitivity (Notes 1 & 2) Static Phase Error (Note 2) PhaseLocked Loop PullIn Range PhaseLocked Loop HoldIn Range
NOTES: 1. Referenced to composite video input color burst. NOTES: 2. See paragraph 1 of the Functional Description text.
5 mVpp mVpp deg Note 2 deg/100 Hz Hz
1
1, 2
Figure 1. Typical VCXO Gain
4Xf sc, OUTPUT (PIN 5) FREQUENCY (MHz) FOR NTSC KOPAL 14.320 14.318 14.316 14.314 14.312 1.0
The gain must be estimated from the operating point. KOPAL is the gain for PAL applications and KONTSC is the gain for NTSC applications.
4Xfsc , OUTPUT (PIN 5) FREQUENCY (MHz) FOR PAL
14.322
17.745
Table 1. Crystal Specifications
Frequency Mode Frequency Tolerance @ 25°C df/dfo 0°C 70°C Load Capacitance ESR C1 (Internal Series Capacitance) 14.31818 MHz (NTSC) 17.734475 MHz (PAL) Fundamental 40 ppm 20 pF 50 15 mpF
17.740 KONTSC 17.735 17.730 17.725 17.719 6.0
0
1.0
2.0
3.0
4.0
5.0
VCO CONTROL VOLTAGE (PIN 3 VOLTAGE) (V)
2
MOTOROLA ANALOG IC DEVICE DATA
MC44144
Figure 2. Representative Schematic Diagram
Composite Video 75 0.1µ 8 7 6 Video In Clamp In Reference Subcarrier Phase Detector 1.0k 5 1.0n 4X Subcarrier Output
+ 5.0
Burst Gate
Voltage Reference 2.6V
Clamp Out Gate Pulse Video Clamp
Phase Det Out
Subcarrier Reference Output 1 1.0k 1.0n
Divide by 4
Voltage 4X Ref Control Out Input VCO 4X Ref Crystal Drive 2 3 4 14.32/ 17.73MHz 47k 470p 0.1µ 5.0 to 25p
Subcarrier Output
FUNCTIONAL DESCRIPTION
The MC44144 is designed to implement the color sync function in a video system. When provided NTSC/PAL composite video or composite chroma and burst gate inputs, the IC will phaselock a Voltage Controlled Crystal Oscillator (VCXO) to the color burst. Both 4X and 1X subcarrier frequency outputs are provided by the IC. The VCXO operates off of a 4X subcarrier crystal and The VCXO operates off a 4X subcarrier crystal and is capable of at least ± 600 Hz of pullin. The tradeoff for such a wide pullin range is a resultant "soft" lock, or a 3° phase shift per 100 Hz change in oscillator freerun or input reference frequency. In addition to providing the gate pulse for the MC44144 phase detector, the Burst Gate input also initiates a clamp pulse that sets up the level of the composite video at the input to the Phase Detector. The start and duration of the Gate Pulse should be timed so that the pulse envelopes the color burst of the video signal, but not so wide as to gate sync or video into the Phase Detector. The Phase Detector is enabled when the voltage at the Burst Gate input (Pin 7) is above the nominal 2.2 V threshold. While this makes possible the ability to lock to a color burst, it does not exclude the possibility of lock to a constant reference. If a constant source is to be the reference, the Phase Detector can be permanently enabled by holding the voltage on the Phase Detector input pin higher than the threshold voltage. The phase detector gain must be specified in two ways, for a constant reference and for a burstlocked application. The gain in a constant reference application is specified by the maximum current output with the maximum phase error. For a maximum phase error of /2 radians the maximum current available is approximately 200 µA. So the phase detector gain is defined as, KPD = 200/(/2)(µA/rad S sec) For a burstlocked application, the Phase Detector is active for only the duration of the color burst. Therefore the phase detector gain must be specified as an average gain over a line period. In this case the phase detector gain for NTSC and for PAL applications is, KPDNTSC = (8/(/2))(µA/rad S sec) and, KPDPAL = (7/(/2))(µA/rad S sec) A suitable filter for both types of applications is shown in the test schematic Figure 2. This same filter also works for both NTSC and PAL applications. The 4X subcarrier Voltage Controlled Crystal Oscillator (VCXO) uses a design that enables the use of series or parallel resonant types of crystals. Still, layout and crystal positioning are critical as the oscillator frequency is sensitive to shunt capacitance. Care should be taken to keep the crystal close to the IC and crystal switching should be avoided. A suitable parallel type crystal would meet the specifications in Table 1. A plot showing the VCXO gain is shown in Figure 1. From this plot the gain must be estimated from the operating point. KOPAL is the gain for PAL applications and KONTSC is the gain for NTSC applications.
MOTOROLA ANALOG IC DEVICE DATA
3
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