A6278 ALLEGRO [Allegro MicroSystems], A6278 Datasheet - Page 6

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

A6278
A6279
Logic Levels: V
Logic Levels: V
A6278, n = 7
A6279, n = 15
DD
DD
and
and GND
and GND
LED Open Circuit Detection (Test) Mode Timing Requirements
(A) To enter LED OCD mode, a minimum of one CLOCK pulse is required after LATCH ENABLE is brought back low.
(C) When returning to Normal mode, a minimum of three CLOCK pulses is required after OUTPUT ENABLE is brought back high.
(B) To output the latched error code, OUTPUT ENABLE must be held low a minimum of 3 CLOCK cycles.
DATA OUT
DATA OUT
OUTPUT
OUTPUT
ENABLE
ENABLE
ENABLE
ENABLE
OUTPUT
ENABLE
CLOCK
CLOCK
OUTPUT
LATCH
LATCH
DATA IN
ENABLE
ENABLE
CLOCK
SERIAL
SERIAL
SERIAL
CLOCK
LATCH
OUT0
OUT1
OUTn
t
t
SU(OE1)
SU(OE1)
t
SU(D)
SDI n
t
t
high
high
Normal Mode Timing Requirements
t
t
high
H(D)
0
t
t
low
1
low
t
SDI n-1
low
1
Don't Care
Don't Care
Don't Care
Don't Care
Don't Care
t
W(OE1)
t
H(OE1)
t
H(OE1)
t
SU(LE1)
Serial-Input, Constant-Current Latched
1
LED Drivers with Open LED Detection
2
2
t
H(LE1)
3
SDI 0
t
t
SU(LE)
p(DO)
SDO n
1
3
n
t
H(LE)
SDO n
SDO n-1
t
SU(OE)
A6278, n = 7
A6279, n = 15
t
P(OE)
SDO n-2
t
D(Total)
t
D
t
W(OE)
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
SDO 0
t
P(OE)
t
D(Total)
t
D
t
W(OE)
6