ALLEGRO A6821

Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
Package A
16-pin DIP
A merged combination of bipolar and MOS technology gives these
devices an interface flexibility beyond the reach of standard logic
buffers and power driver arrays. Typical applications include driving
multiplexed LED displays or incandescent lamps.
The A6821 has an eight-bit CMOS shift register and CMOS control
circuitry, eight CMOS data latches, and eight bipolar current-sinking
Darlington output drivers.
The CMOS inputs are compatible with standard CMOS logic levels.
TTL circuits may require the use of appropriate pull-up resistors. By
using the serial data output, the drivers can be cascaded for interface
applications requiring additional drive lines.
Package LW
16-pin Wide Body SOIC
The A6821SA is furnished in a standard 16-pin plastic DIP. The
A6821EA is a 16-pin plastic DIP, capable of operation from -40°C to
+85°C. The A6821SLW is a 16-lead wide-body SOIC, for surfacemount applications. These devices are lead (Pb) free, with 100% matte
tin plated leadframes.
FEATURES
ABSOLUTE MAXIMUM RATINGS
Output Voltage, VOUT .........................................50 V
Logic Supply Voltage, VDD...................................7 V
Input Voltage Range, VIN ..............–0.3 V to VDD +0.3 V
Continuous Output Current (each output), IOUT ... 500 mA
Package Power Dissipation, PD
A6821SA/A6821EA..................................2.1 W
A6821SLW............................................... 1.5 W
Operating Temperature Range
Ambient Temperature, TA ............–20°C to +85°C
Storage Temperature, TS ..........–55°C to +150°C
„
3.3 V to 5 V logic supply range
„
Power on reset (POR)
„
„
Schmitt trigger inputs for improved
noise immunity
To 10 MHz data input rate
„
Low-power CMOS logic and latches
„
CMOS, TTL compatible
„
High-voltage current-sink outputs
„
–40°C operation available
„
Internal pull-up/pull down resistors
APPLICATIONS
„
„
Multiplexed LED displays
Incandescent lamps
Caution: CMOS devices have input-static protection,
but are susceptible to damage when exposed to
extremely high static-electrical charges.
Use the following complete part numbers when ordering:
Part Number
A6821SA-T
A6821EA-T
A6821SLW-T
Package
16-pin DIP
16-pin DIP
16-pin wide body SOIC
Ambient
–20ºC to +85ºC
–40ºC to +85ºC
–20ºC to +85ºC
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
Functional Block Diagram
C LOC K
LOG IC
S UP P LY
V DD
S E R IAL
DAT A IN
S E R IAL
DAT A OUT
S E R IAL-P AR ALLE L S HIF T R E G IS T E R
LOG IC
G R OUND
S T R OB E
LAT C HE S
OUT P UT E NAB LE
(AC T IV E LOW)
MOS
B IP OLAR
P OWE R
G R OUND
S UB
OUT 1 OUT 2 OUT 3 OUT 4 OUT 5 OUT 6 OUT 7 OUT 8
Typical Input Circuits
Typical Output Driver
VDD
OUT
STROBE
OUTPUT
ENABLE
7.2 k Ω
3 kΩ
SUB
VDD
CLOCK
SERIAL
DATA IN
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
ELECTRICAL CHARACTERISTICS1 Unless otherwise noted: TA = 25°C, logic supply operating voltage Vdd = 3.0 V to 5.5 V
Vdd = 3.3 V
Characteristic
Min.
Typ.
Typ.
Max.
Units
VOUT = 50 V
–
–
10
–
–
10
μA
IOUT = 100 mA
–
–
1.1
–
–
1.1
V
IOUT = 200 mA
–
–
1.3
–
–
1.3
V
IOUT = 350 mA
–
–
1.6
–
–
1.6
V
Symbol
Output Leakage Current
ICEX
Collector–Emitter Saturation
Voltage
VCE(SAT)
Input Voltage
Input Resistance
Test Conditions
Maximum Clock Frequency2
2.2
–
–
3.3
–
–
V
VIN(0)
–
–
1.1
–
–
1.7
V
kΩ
50
–
–
50
–
–
VOUT(1)
IOUT = –200 μA
2.8
3.05
–
4.5
4.75
–
V
VOUT(0)
IOUT = 200 μA
–
0.15
0.3
–
0.15
0.3
V
fc
10
–
–
10
–
–
MHz
IDD(1)
One output on, OE = L, ST = H
–
–
2.0
–
–
2.0
mA
IDD(0)
All outputs off, OE = H, ST = H,
P1 through P8 = L
–
–
100
–
–
100
μA
tdis(BQ)
VCC = 50 V, R1 = 500 Ω, C1 ≤ 30 pF
–
–
1.0
–
–
1.0
μs
ten(BQ)
VCC = 50 V, R1 = 500 Ω, C1 ≤ 30 pF
–
–
1.0
–
–
1.0
μs
tp(STH-QL)
VCC = 50 V, R1 = 500 Ω, C1 ≤ 30 pF
–
–
1.0
–
–
1.0
μs
tp(STH-QH)
VCC = 50 V, R1 = 500 Ω, C1 ≤ 30 pF
–
–
1.0
–
–
1.0
μs
tf
VCC = 50 V, R1 = 500 Ω, C1 ≤ 30 pF
–
–
1.0
–
–
1.0
μs
tr
VCC = 50 V, R1 = 500 Ω, C1 ≤ 30 pF
–
–
1.0
–
–
1.0
μs
IOUT = ±200 μA
–
50
–
–
50
–
ns
Logic Supply Current
Output Enable-to-Output Delay
Strobe-to-Output Delay
Output Fall Time
Output Rise Time
Clock-to-Serial Data Out Delay
Max. Min.
VIN(1)
RIN
Serial Data Output Voltage
Vdd = 5 V
tp(CH-SQX)
1Positive
(negative) current is defined as conventional current going into (coming out of) the specified device pin.
2Operation at a clock frequency greater than the specified minimum value is possible but not warranteed.
Truth Table
Serial
Data Clock
Input Input
Shift Register Contents
I1
I2
I3
...
I8
Serial
Data
Output
H
H
R1 R2 ...
R7
R7
L
L
R1 R2 ...
R7
R7
X
R1 R2 R3 ...
R8
R8
X
X
X
...
P1 P2 P3 ...
L = Low Logic Level
H = High Logic Level
X = Irrelevant
P = Present State
X
X
P8
P8
Latch Contents
Strobe
Input
I1
I2
Output Contents
I1 I2 I3 ... I8
...
I8
L
R1 R2 R3 ...
R8
H
P1 P2 P3 ...
P8
L
P 1 P2 P3 ... P8
X
X
H
H
X
I3
Output
Enable
Input
X
...
H H ... H
R = Previous State
OE = Output Enable
ST = Strobe
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
Timing Requirements and Specifications
(Logic Levels are VDD and Ground)
C
50%
CLOCK
A
SERIAL
DATA IN
B
DATA
50%
t p(CH-SQX)
SERIAL
DATA OUT
DATA
50%
D
50%
STROBE
OUTPUT ENABLE
E
LOW = ALL OUTP UTS E NABLE D
tp(STH-QH)
tp(STH-QL)
90%
DATA
OUT N
10%
HIGH = ALL OUTP UTS BLANKE D (DIS ABLE D)
OUTPUT ENABLE
50%
t en(BQ)
tr
tf
t dis(BQ)
OUT N
10%
Key
Description
A
Data Active Time Before Clock Pulse (Data Set-Up Time)
B
DATA
90%
50%
Symbol
tsu(D)
Time (ns)
Data Active Time After Clock Pulse (Data Hold Time)
th(D)
25
C
Clock Pulse Width
tw(CH)
50
D
Time Between Clock Activation and Strobe
tsu(C)
100
E
Strobe Pulse Width
tw(STH)
50
NOTE: Timing is representative of a 10 MHz clock. Higher speeds may be
attainable; operation at high temperatures will reduce the specified maximum clock frequency.
Powering-on with the inputs in the low state ensures that the registers and
latches power-on in the low state (POR).
Serial Data present at the input is transferred to the shift register on the logical
0 to logical 1 transition of the CLOCK input pulse. On succeeding CLOCK
pulses, the registers shift data information towards the SERIAL DATA OUTPUT. The SERIAL DATA must appear at the input prior to the rising edge of the
CLOCK input waveform.
25
Information present at any register is transferred to the respective latch
when the STROBE is high (serial-to-parallel conversion). The latches will
continue to accept new data as long as the STROBE is held high. Applications where the latches are bypassed (STROBE tied high) will require that
the OUTPUT ENABLE input be high during serial data entry.
When the OUTPUT ENABLE input is high, all of the output buffers are
disabled (OFF). The information stored in the latches or shift register is not
affected by the OUTPUT ENABLE input. With the OUTPUT ENABLE
input low, the outputs are controlled by the state of their respective latches.
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
4
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
Maximum Allowable Duty Cycle, IOUT = 200 mA, VDD = 5 V
Number of
Outputs ON
A mbient T emperature
40 °C
50 °C
60 °C
25 °C
70 °C
A6821SA/A6821EA
8
7
6
5
4
3
2
1
90%
100%
100%
100%
100%
100%
100%
100%
79%
90%
100%
100%
100%
100%
100%
100%
72%
82%
96%
100%
100%
100%
100%
100%
65%
74%
86%
100%
100%
100%
100%
100%
57%
65%
76%
91%
100%
100%
100%
100%
67%
77%
90%
100%
100%
100%
100%
100%
59%
68%
79%
95%
100%
100%
100%
100%
54%
62%
72%
86%
100%
100%
100%
100%
49%
56%
65%
78%
98%
100%
100%
100%
43%
49%
57%
68%
86%
100%
100%
100%
A6821SLW
8
7
6
5
4
3
2
1
Terminal List Table
Name
Description
Pin
CLK
Clock
1
VDD
Serial Data In
2
Logic Ground*
3
Logic Supply
4
Serial Data Out
5
ST
Strobe
6
OE
Output Enable (active low)
7
SUB
Power Ground*
8
OUT8
Serial Data Output
9
OUT7
Serial Data Output
10
OUT6
Serial Data Output
11
OUT5
Serial Data Output
12
OUT4
Serial Data Output
13
OUT3
Serial Data Output
14
OUT2
Serial Data Output
15
OUT1
Serial Data Output
16
* There is an indeterminate resistance between logic ground and power ground.
For proper operation, these terminals must be externally connected together.
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
5
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
Package A
16-pin DIP
Package LW
16-pin Wide Body SOIC
16
OUT 1
2
15
OUT 2
LOG IC
G R OUND
3
14
OUT 3
OUT 4
LOG IC
S UP P LY
4
13
OUT 4
12
OUT 5
S E R IAL
DAT A OUT
5
12
OUT 5
ST
11
OUT 6
S T R OB E
6
ST
11
OUT 6
OE
10
OUT 7
OUT P UT
E NAB LE
7
OE
10
OUT 7
9
OUT 8
P OWE R
G R OUND
8
9
OUT 8
C LOC K
1
2
15
OUT 2
S E R IAL
DAT A IN
LOGIC
GROUND
3
14
OUT 3
LOGIC
SUPPLY
4
13
SERIAL
DATA OUT
5
STROBE
6
OUTPUT
ENABLE
7
POWER
GROUND
8
SUB
LATCHES
VDD
SHIFT REGISTER
SERIAL
DATA IN
CLK
C LK
V DD
LAT C HE S
OUT 1
1
S HIF T R E G IS TE R
16
CLOCK
S UB
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
6
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
Package A
16-pin DIP
Dimensions in Inches
(controlling dimensions)
0.014
0.008
9
16
0.430
MAX
0.280
0.240
0.300
BSC
1
0.070
0.045
0.100
0.775
0.735
8
0.005
BSC
MIN
0.210
MAX
0.015
0.150
0.115
MIN
0.022
0.014
Dwg. MA-001-16A in
Dimensions in Millimeters
(for reference only)
0.355
0.204
9
16
10.92
MAX
7.11
6.10
7.62
BSC
1
1.77
1.15
2.54
19.68
18.67
8
0.13
BSC
MIN
5.33
MAX
0.39
3.81
2.93
MIN
0.558
0.356
Dwg. MA-001-16A mm
NOTES: 1. Lead thickness is measured at seating plane or below.
2. Lead spacing tolerance is non-cumulative.
3. Exact body and lead configuration at vendor’s option within limits shown.
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
7
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
Package LW
16-pin Wide Body SOIC
Dimensions in Inches
(for reference only)
16
9
0.0125
0.0091
0.419
0.394
0.2992
0.2914
0.050
0.016
0.020
0.013
1
2
0.050
3
0° TO 8°
BSC
0.4133
0.3977
0.0926
0.1043
0.0040 MIN.
Dwg. MA-008-16A in
Dimensions in Millimeters
(controlling dimensions)
16
9
0.32
0.23
10.65
10.00
7.60
7.40
1.27
0.40
0.51
0.33
1
2
1.27
3
10.50
10.10
BSC
0° TO 8°
2.65
2.35
0.10 MIN.
Dwg. MA-008-16A mm
NOTES: 1. Lead spacing tolerance is non-cumulative.
2. Exact body and lead configuration at vendor’s option within limits shown.
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8
Data Sheet
26185.112B
A6821
DABiC-5 8-Bit Serial Input Latched Sink Drivers
The products described here are manufactured under one or
more U.S. patents or U.S. patents pending.
Allegro MicroSystems, Inc. reserves the right to make, from time
to time, such departures from the detail specifications as may be
required to permit improvements in the performance, reliability,
or manufacturability of its products. Before placing an order, the
user is cautioned to verify that the information being relied upon is
current.
Allegro products are not authorized for use as critical components in life-support devices or systems without express written
approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other
rights of third parties which may result from its use.
Copyright©2004, 2005 AllegroMicrosystems, Inc.
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
9