ROHM BU4042B Datasheet

1

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.

4) High fan-out.

5) Direct drive of 2 L-TTL inputs and 1LS-TTL input.

•

Block diagram

Q

4

1

Q

1

2

Q

1

3

D1

4

CLOCK

5

POLARITY

6

D

2

7

V

SS

8

V

DD

16

Q4

15

CL D

D4

14

D3

13

Q3

12

Q3

11

Q2

10

Q2

9

QQ

CL D

QQ

CL

D
QQ

CL D

QQ

•

Logic circuit diagram

(6)

LATCH

1

D

1 (4)

D

2 (7)

D

3 (13)

D

4 (14)

CLOCK

(5)

POLARITY

(3)

(10)
(9)

(11)
(12)

(1)
(15)

(2)

Q

1

Q2
Q2

Q3
Q3

Q4
Q4

LATCH

2

LATCH

3

LATCH

4

Q1

•

Truth table

CLOCK POLARITY Q

LL D
H L LATCH
HH D
L H LATCH

2

Standard ICs BU4042B

•

Absolute maximum ratings (Ta = 25°C, VSS = 0V)

Parameter Symbol Limits Unit

Power supply voltage V

DD V

Power dissipation mW
Operating temperature – 40 ~ + 85

°C
Storage temperature – 55 ~ + 150 °C
Input voltage V

IN V

Pd
Topr
Tstg

1000 (DIP)

– 0.3 ~ + 18

– 0.3 ~ VDD + 0.3

•

Electrical characteristics

DC characteristics (unless otherwise noted, Ta = 25°C, V

SS = 0V)

Parameter Symbol Min. Typ. Max. Unit Conditions

Input high level voltage
(DATA)

V

IH

3.5 ——
V

5

—7.0 —— 10

11.0 —— 15

Input high level voltage

CLOCK
POLARITY

()

V

IH

3.5 ——
V

5

—7.0 —— 10

11.25 —— 15

Input low level voltage
(DATA)

V

IL

——1.5

V

5

———3.0 10

——4.0 15

Input low level voltage

V

IL

——1.5

V

5

———3.0 10

——3.75 15

Input high level current I

IH

——0.3 µ

A15V

IH

= 15V

Input low level current I

IL

— — – 0.3 µ

A15V

IL

= 0V

Output high level voltage V

OH

4.95 ——
V

5

I

O

= 0mA9.95 —— 10

14.95 —— 15

Output low level voltage V

OL

——0.05

V

5

I

O

= 0mA——0.05 10

——0.05 15

Output high level current I

OH

– 0.16 ——

mA

5VOH = 4.6V

– 0.4 —— 10 V

OH

= 9.5V

– 1.2 —— 15 V

OH

= 13.5V

Output low level current I

OL

0.44 ——

mA

5VOL = 0.4V

1.1 —— 10 V

OL

= 0.5V

3.0 —— 15 V

OL

= 1.5V

Static current dissipation I

DD

——4.0

µ

A

5

V

I

= VDD or GND——8.0 10

——16.0 15

V

DD

(V)

CLOCK
POLARITY

()