A6278 ALLEGRO [Allegro MicroSystems], A6278 Datasheet - Page 5

• Manufacturer Part Number: A6278
• Description: Serial-Input Constant-Current Latched LED Drivers with Open LED Detection
• Manufacturer: ALLEGRO [Allegro MicroSystems]

A6278
A6279
L = Low logic (voltage) level
H = High logic (voltage) level
X = Don’t care
P = Present state
R = Previous state
n = 7 for the A6278, n = 15 for the A6279
Serial
Input
Data
IN
H
X
L
OUTPUT ENABLE
(active low)
Clock
Input
and
I
H R
L R
R
X
P
0
0
0
Shift Register Contents
R
P
X X
I
0
1
0
1
1
R
R
P
R
I
1
1
2
2
2
…
…
…
V
…
…
…
DD
R
R
X
P
R
I
n-2
n-1
n-1
n-1
n-2
Inputs and Outputs Equivalent Circuits
R
X
R
P
R
I
n-1
n
n
n
n-1
IN
SERIAL DATA IN
CLOCK and
Serial
Data
R
R
Out
R
P
X
n-1
n-1
n
n
Serial-Input, Constant-Current Latched
LED Drivers with Open LED Detection
Truth Table
Enable
Latch
Input
H
L
V
DD
I
R
P
X
0
0
0
P
R
X X
I
1
1
1
Latch Contents
P
IN
LE
R
I
2
2
2
…
…
…
LATCH ENABLE
…
X
R
P
I
n-1
n-1
n-1
X
R
P
I
n
n
n
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
Enable
Output
Input
H
L
V
V
DD
DD
I
P
H
0
0
SERIAL DATA OUT
P
Output Contents
I
H H
1
1
P
I
2
2
…
…
…
V
DD
P
H
I
n-1
n-1
OUT
P
H
I
n
n
5