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5817 Datasheet, PDF (5/6 Pages) Allegro MicroSystems – ADDRESSABLE 28-LINE DECODER/DRIVER
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5817
ADDRESSABLE
28-LINE DECODER/DRIVER
APPLICATIONS INFORMATION
This device is intended specifically for, although
certainly not limited to, driving ink-jet print heads. In
this application, a certain minimum energy (a function
of load voltage and output pulse duration) is required
for proper operation, while excessive energy will
degrade the life of the print head. The output pulse
duration (tOUT) is equal to tENABLE + tPLH – tPHL, where
tPHL is adjusted during manufacture to compensate for
variations in the output saturation voltage (VCE(SAT)).
For the A5817SEP, the relationship between tOUT
and tENABLE at TA = 25°C is:
tOUT = tENABLE ([VCE(SAT)(actual) – VCE(SAT)(typical)]
x 330 ns) + 25 ns + 110 ns.
For most applications, this will result in a driver-
contribution-to-energy-error of less than ±4%.
A logic low on the CHIP ENABLE input will
prevent the drivers from turning ON, regardless of the
state of other inputs or the logic supply voltage. The
CHIP ENABLE input has a slow response time and
should not be used as a high-speed control line. For
proper operation, all ground terminals should be
connected to a common ground on the printed wiring
board. The IC (Internal Connection) terminals are
used to program the turn-on time of the device and
MUST be left electrically unconnected (floating) for
proper operation.
IND
(MSB)
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
DECODER TRUTH TABLE
INC
INB
INA
(LSB)
N
0
0
0
0
0
0
1
1
0
1
0
2
0
1
1
3
1
0
0
4
1
0
1
5
1
1
0
6
1
1
1
7
0
0
0
8
0
0
1
9
0
1
0
10
0
1
1
11
1
0
0
12
1
0
1
13
1
1
0
ALL OFF
1
1
1
ALL OFF
Depending on the four address inputs, the 4-to-14 line
decoder selects one driver from each of the 14 output A
and B banks of sink drivers according to the Decoder
Truth Table. The state of the selected outputs is deter-
mined by the OUTPUT ENABLE inputs as shown in the
Enable Truth Table.
CHIP
ENABLE
0
1
1
1
1
X = Irrelevant
OUTPUT
ENABLEA
X
1
0
1
0
ENABLE TRUTH TABLE
OUTPUT
ENABLEB
X
1
1
0
0
OUTPUTS (OFF unless otherwise specified.
For the value of N see the Decoder Truth Table)
ALL OFF
ALL OFF
OUTAN ON
OUTBN ON
OUTAN ON, OUTBN ON
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