CD74ACT297 Datasheet, PDF (9/12 Pages) Texas Instruments – DIGITAL PHASE-LOCKED LOOP

CD74ACT297
DIGITAL PHASE-LOCKED LOOP
SCHS297A – AUGUST 1998 – REVISED SEPTEMBER 1999
φB
φA1
XORPD OUT
92CS-40451
Figure 6. Exclusive-OR Phase-Detector Waveforms
I/D CLK
1/F max
tw
1.5 V
1.5 V
tPHL
I/D OUT
90%
10%
tTLH
50% VCC
tPHL
50% VCC
tTHL
3V
0V
≈VCC
VOL
92CS-40452
Figure 7. Waveforms Showing Clock (ID CLK) to Output (ID OUT) Propagation Delays,
Clock Pulse Duration, and Maximum Clock Pulse Frequency
3V
φB
1.5 V
1.5 V
0V
φA1
XORPD OUT
1.5 V
1.5 V
tPHL
tPLH
50% VCC 50% VCC 50% VCC
tPLH
tPHL
3V
0V
50% VCC
≈VCC
VOL
92CS-43151
Figure 8. Waveforms Showing Phase Input (φB, φA2) to Output (XORPD OUT) Propagation Delays
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