BU4042B Datasheet, PDF (1/4 Pages) Rohm – Quad D latch

Standard ICs
Quad D latch
BU4042B
The BU4042B is a four-circuit D latch with a common clock line and separate data input terminals.
When the polarity input is set to “H”, input (D) is presented to output (Q) as is, as long as the clock input is rising, and
when the clock input falls, output (Q) holds input (D) at that point. While the clock input is falling, output (Q) does not
change even if input (D) changes.
Also, if the polarity input is set to “L”, input (D) is presented to output (Q) as is, as long as the clock input is at “L”
level, and when the clock input goes to “H” level, latching takes place.
•^Features
1) Low power dissipation.
2) Wide range of operating power supply voltages.
3) High input impedance.
•^{Block diagram}
4) High fan-out.
5) Direct drive of 2 L-TTL inputs and 1LS-TTL input.
•^{Logic circuit diagram}
Q4 1
Q1 2
Q1 3
D1 4
CLOCK 5
POLARITY 6
D2 7
VSS 8
CL D
QQ
CL D
QQ
CL D
QQ
CL D
QQ
16 VDD
15 Q4
14 D4
13 D3
12 Q3
11 Q3
10 Q2
9 Q2
D1 (4)
D2 (7)
D3 (13)
D4 (14)
CLOCK
(5)
POLARITY
(6)
LATCH
1
LATCH
2
LATCH
3
LATCH
4
(2) Q1
(3) Q1
(10) Q2
(9) Q2
(11) Q3
(12) Q3
(1) Q4
(15) Q4
•^{Truth table}
CLOCK
L
H
H
L
POLARITY
L
L
H
H
Q
D
LATCH
D
LATCH
1