CD74ACT297_14 Datasheet, PDF (4/18 Pages) Texas Instruments – DIGITAL PHASE-LOCKED LOOP

CD74ACT297
DIGITAL PHASE-LOCKED LOOP
SCHS297D – AUGUST 1998 – REVISED JUNE 2002
functional block diagram
2
A
1
B ₁₅
C ₁₄
D
1
2
4
8
0
4
K CLK
K Counter
X/Y
14 13 12 11 10 9
8
76
5 43 2 1
To Mode Controls 12–2 (11 stages not shown)
6
D/U
ENCTR ³
C20
20D
C20
20D
I/D CLK ⁵
Power-Up Reset
l=1 1
RR
T
T
T
T
R
R
14D ^R
14T
M14
M14
14T
14D
R
I/D Circuit
21D
C21
21D
C21
21D
C21
C21
21D
C21
21D
C21
21D
R
13D
13T
M13
M13
13T
13D
R
R
R
1T
T
1T
T
R
R
Decrement
Increment
21D
C21
C21
21D
21J
C21
21K
7 _{I/D OUT}
9
φA1
φB ¹⁰
φA2 ¹³
Exclusive-OR Phase Detector
Edge-Controlled Phase Detector
S
S
R
R
11
XORPD OUT
12
ECPD OUT
4
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