480227 Datasheet, PDF (405/794 Pages) Texas Instruments – Pocket Data Book

297
DIGITAL PHASE-LOCKED-LOOP FILTERS
(2)
A ₍₁₎
B ₍₁₅₎
C ₍₁₄₎
D
Logic Diagram (SN74LS)
1
2
4
8
0
K COUNTER
X/Y
14 13 12 11 10 9 8 7 6 5 4 3 2 1
(4)
KCLK
(6)
D/U
(3)
ENCTR
C20
20D
C20
20D
POWER-UP RESET
I=1 1
(5)
I/D CLK
RR
T
T
T
T
RR
TO MODE CONTROLS 12-2 (11-STAGES NOT SHOWN)
14D ^R
14T
M14
M14
14T
14D _R
13D ^R
13T
M13
M13
13T
13D _R
1DR
R
1T
T
M1
M1
1T
T
1D _R
R
I/D CIRCUIT
21D
C21
21D
C21
21D
C21
C21
21D
C21
21D
C21
21D
DECREMENT
INCREMENT
21D
C21
C21
21D
21J
C21
21K
(7)
I/D OUT
(9)
fA1
(10)
fB
(13)
fA2
EXCLUSIVE-OR PHASE DETECTOR
EDGE CONTROLLED PHASE DETECTOR
S
S
R
R
(11) _XORPD
OUT
(12) _ECPD
OUT
400
: OBSOLETED or NOT RECOMMENDED NEW DESIGNS