A6276 Allegro MicroSystems, A6276 Datasheet - Page 10

• Manufacturer Part Number: A6276
• Description: 16-BIT SERIAL-INPUT/ CONSTANTCURRENT LATCHED LED DRIVER
• Manufacturer: Allegro MicroSystems

The load current per bit (I
(R
allowable package power dissipation is determined as
The actual package power dissipation is
When the load supply voltage is greater than 3 V to 5 V,
considering the package power dissipating limits of these
devices, or if P
reducer (V
designed to operate with driver voltage drops (V
0.4 V to 0.7 V with LED forward voltages (V
4.0 V. If higher voltages are dropped across the driver,
package power dissipation will be increased significantly.
To minimize package power dissipation, it is recom-
mended to use the lowest possible load supply voltage or
to set any series dropping voltage (V
with V
diode (V
6276
16-BIT SERIAL-INPUT,
CONSTANT-CURRENT
LATCHED LED DRIVER
EXT
100
80
60
40
20
) as shown in the figure below.
0
100
DROP
P
Z
), or a series string of diodes (approximately
D
CURRENT-CONTROL RESISTANCE, R
DROP
(act) = dc(V
= I
200
D
o
) should be used.
P
(act) > P
• R
V
D
(max) = (150 - T
DROP
DROP
300
CE
= V
for a single driver, or a Zener
D
O
(max), an external voltage
500
• I
) is set by the external resistor
LED
O
• 16) + (V
700
- V
These devices are
F
A
1 k
)/R
- V
DROP
The maximum
CE
EXT
V
JA
DD
CE
) as
.
= 0.7 V
IN OHMS
• I
2 k
F
DD
) of 1.2 V to
CE
).
3 k
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
) of
Dwg. GP-061
5 k
0.7 V per diode) for a group of drivers. If the available
voltage source will cause unacceptable dissipation and
series resistors or diode(s) are undesirable, a regulator
such as the Sanken Series SAI or Series SI can be used to
provide supply voltages as low as 3.3 V.
For reference, typical LED forward voltages are:
ground and power-ground terminal. If ground pattern
layout contains large common-mode resistance, and the
voltage between the system ground and the LATCH
ENABLE or CLOCK terminals exceeds 2.5 V (because of
switching noise), these devices may not operate correctly.
V LED
V DROP
V F
V CE
Blue
Green
Yellow
Amber
Red
Infrared
This device has a common logic-
1.9 – 2.65 V
1.6 – 2.25 V
3.0 – 4.0 V
1.8 – 2.2 V
2.0 – 2.1 V
1.2 – 1.5 V
Dwg. EP-064