OUT1
IN4
IN5
IN6
IN7
IN8
FAULT
IN3
2987
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
OUT8
IN2
IN1
4.75 to 35 V
1 to 8 Load
Components
CPU
GND
VS
OE/R
¯
Description
Providing overcurrent protection for each of its eight
sourcing outputs, the UDN2987LW-6 driver is used as an
interface between standard low-level logic and relays, motors,
solenoids, LEDs, and incandescent lamps. This device includes
thermal shutdown and output transient protection/clamp diodes
for use with sustaining voltages to 35 V.
In this driver, each channel includes a latch to turn off that
channel if the maximum channel current is exceeded. All
channels are disabled if the thermal shutdown is activated. A
common FAULT output is used to indicate either chip thermal
shutdown or any overcurrent condition. All outputs are enabled
by pulling the common OE/R input high. When OE/R
¯ is low,
all outputs are inhibited and the eight latches are reset. The
OE/R
¯function can be especially important during power-up,
in preventing floating inputs from turning on the outputs.
Under normal operating conditions, each of eight outputs
will source in excess of 100 mA continuously at an ambient
temperature of 25°C and a supply of 35 V. The overcurrent
fault circuit will protect the device from short-circuits to ground
with supply voltages of up to 30 V.
29876-DS, Rev. 6
Features and Benefits
▪ 4.75 to 35 V driver supply voltage
▪ Output enable-disable (OE/R)
▪ 350 mA output source current
▪ Overcurrent protected
▪ Internal ground clamp diodes
▪ Output Breakdown Voltage 35 V minimum
▪ TTL, DTL, PMOS, or CMOS compatible inputs
▪ Internal Thermal Shutdown (TSD)
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
Continued on the next page…
Package: 20-pin SOICW (suffix LW)
Typical Application
Not to scale
UDN2987x-6
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
2
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Parameter Symbol Notes Rating Units
Supply Voltage VS35 V
Continuous Output Current* IOUT Outputs are disabled at approximately –500 mA –500 mA
FAULT Output Voltage VCE 35 V
FAULT Output Current IC30 mA
Input Voltage VIN –0.3 to 14 V
Junction Temperature TJ150 °C
Storage Temperature Range TSRange N –55 to 150 °C
Operating Temperature Range TA–20 to 85 °C
*For input and output current specifications, negative current is defined as coming out of (sourcing) the specified device pin.
Selection Guide
Absolute Maximum Ratings
Part Number Packing Package
UDN2987LWTR-6-T 1000 pieces/13-in. reel 20-pin SOIC, wide body
The inputs are compatible with 5 and 12 V logic systems: TTL,
Schottky TTL, DTL, PMOS, and CMOS. In all cases, the output is
switched ON by an active high input level. Compared to predecessor
devices, the UDN2987LW-6 has a significantly faster TPHL (200 ns
typical) and a lower driver supply voltage rating (4.75 V), which
allows the use of 5 V logic.
The UDN2987LW-6 is supplied in a 20-lead small-outline (SOIC-W)
plastic package. All packages are lead (Pb) free, with 100% matte-
tin leadframe plating.
Description (continued)
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
3
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Functional Block Diagram
Pin-Out Diagram Terminal List Table
Number Name Description
1 IN1 Logic input 1
2 IN2 Logic input 2
3 IN3 Logic input 3
4 IN4 Logic input 4
5 IN5 Logic input 5
6 IN6 Logic input 6
7 IN7 Logic input 7
8 IN8 Logic input 8
9 FAULT Fault output
10 OE/ ¯R¯ Logic input for Output Enable and Reset
11 VS Supply voltage
12 GND Supply ground
13 OUT8 Output 8 to load
14 OUT7 Output 7 to load
15 OUT6 Output 6 to load
16 OUT5 Output 5 to load
17 OUT4 Output 4 to load
18 OUT3 Output 3 to load
19 OUT2 Output 2 to load
20 OUT1 Output 1 to load
Dwg. PP-067
1
2
3
4
5
6
7
8
14
15
16
17
18
19
20
9
10 11
12
13
OEN
OE
SENSEN
FF
x8
IN1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
FAULT
OE/R
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
OUT8
GND
VS
IN1
GND
VS
<1Ω
OUT1
IN8 OUT8
FAULT
Driver 1 of 8 drivers
OE/R
¯
+
–
Q
RS
Thermal
Shut Down
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
4
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
ELECTRICAL CHARACTERISTICS, valid at TA = 25°C, VOER = 2.4 V, VS = 35 V, unless otherwise noted
Characteristic Symbol Test Conditions Min. Typ.1Max. Units
Supply Voltage Functional Range VS4.75 — 35 V
Output Leakage Current2IOUTCEX VIN = 0.4 V, all inputs simultaneously – 200 <–5.0 – μA
Output Sustaining Voltage VOUT(sus) IOUT = –350 mA, L = 2.0 mH 35 — — V
Output Saturation Voltage VOUT(SAT)
VIN = 2.4 V, IOUT = –100 mA — 1.6 1.8 V
VIN = 2.4 V, IOUT = –225 mA — 1.7 1.9 V
VIN = 2.4 V, IOUT = –350 mA — 1.8 2.0 V
Channel Shut Down Threshold2IMVIN = 2.4 V, Vs = 30 V – –500 – 370 mA
FAULT Leakage Current ICEX VCC = 35 V — <1.0 100 μA
FAULT Saturation Voltage VCE(SAT) IC = 30 mA — 0.3 0.8 V
Input Voltage VIN(ON) 2.4 — — V
VIN(OFF) — — 0.4 V
Input Current: INx, OE/R
¯ pins IIN(ON)
VIN = 2.4 V — — 100 μA
VIN = 5.0 V — — 600 μA
VIN = 12 V — — 1000 μA
IIN(OFF) VIN = 0.4 V — — 15 μA
Clamp Diode Leakage Current IRVR = 35 V, TA = 70°C — — 50 μA
Clamp Diode Forward Voltage VFIF = 350 mA — 1.5 1.8 V
Supply Current IS(ON) VIN = 2.4 V, all inputs simultaneously; outputs open — 7.0 18 mA
IS(OFF) VIN = 0.4 V, all inputs simultaneously — 6.0 12 mA
Thermal Shut Down TJTSD — 165 — °C
Thermal Hysteresis TJTSDhys —15—°C
Reset Pulse Duration tRPD 1.0 — — μs
Propagation Delay Time tPLH VS = 35 V, RL = 100 Ω, CLOAD = 30 pF — 100 600 ns
tPHL VS = 35 V, RL = 100 Ω, CLOAD = 30 pF — 200 1000 ns
Blank Time tBLANK — 1.0 — μs
1Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions. Performance may vary for indi-
vidual units, within the specified maximum and minimum limits.
2For input and output current specifications, negative current is defined as coming out of (sourcing) the specified device pin.
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
5
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
THERMAL CHARACTERISTICS
Characteristics Symbol Test Conditions Rating Unit
Package Thermal Resistance*RθJA Package LW, on 4-layer board based on JEDEC standard 48 °C/W
*Additional thermal information is available on the Allegro Web site.
T
A
(°C)
P
D
(W)
0
0.5
1.5
2.0
2.5
3.0
3.5
4.0
1.0
25 50 75 100 125 150
Power Dissipation versus Ambient Temperature
(RQJA = 48 ºC/W)
Package LW
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
6
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Characteristic Performance
Allowable Output Current as a Function of Duty Cycle
(Multiply by 78% for UDN2987LW-6)
TA= 25°C, VS = 35 V TA= 50°C, VS = 35 V
0 10 20 30 40 50 60 70 80 90 100
400
350
300
250
200
150
100
50
0
Duty Cycle (%)
Collector Current (mA)
87 6 5 4 3
Quantity of outputs conducting simultaneously
Output Current Waveshapes
0 10 20 30 40 50 60 70 80 90 100
400
350
300
250
200
150
100
50
0
Duty Cycle (%)
Collector Current (mA)
876 5 4 3 2
Quantity of outputs conducting simultaneously
VIN(A) = VIN(B)
ISH
IOUT(A)
IOUT(B)
IM
tBLANK
tRTB
tPLH tPHL
OE/R
—
Output (A) shorted
Momentary fault or capacitive charging (<1μs)
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
7
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Applications Information and Circuit Description
As with all power integrated circuits, the UDN2987LW-6
has a maximum allowable output current rating. The
500 mA rating does not imply that operation at that value
is permitted or even obtainable. The channel output current
trip point is specified as –370 mA, minimum; therefore,
attempted operation at current levels greater than –370 mA
may cause a fault indication and channel shutdown. The
device is tested at a maximum of –350 mA and that is the
recommended maximum output current per driver. It pro-
vides protection for current overloads or shorted loads up to
30 V.
All outputs are enabled by pulling the OE/R
¯
input high.
When OE/R
¯
is low or allowed to float (internal pull-down),
all outputs are inhibited and the latches are reset. Note that
the reset pulse duration (OE/R
¯
low) should be at least 1 μs.
This will ensure safe operation under attempted reset condi-
tions with a shorted load. The latches are also reset during
power-up, regardless of the state of the OE/R
¯
input.
The load current causes a small voltage drop across the
internal low-value sense resistor. This voltage is com-
pared to the voltage drop across a reference resistor with
a constant current. The two resistors are matched to
eliminate errors due to manufacturing tolerances or tem-
perature effects. Each channel includes a comparator and
its own latch. An overcurrent fault (VSENSE > VREF) will
set the affected latch and shut down only that channel.
All other channels will continue to operate normally. The
latch includes a 1 μs blanking delay, tBLANK, to prevent
unwanted triggering due to crossover currents generated
when switching inductive loads. For an abrupt short circuit,
the blanking and output switching times will allow a brief,
permissible current in excess of the trip current before the
output driver is turned off.
A common thermal shutdown disables all outputs if the
chip temperature exceeds 165°C. At thermal shutdown, all
latches are reset. The outputs are disabled until the chip
cools down to approximately 150°C (thermal hysteresis).
In the event of an overcurrent condition on any channel, or
chip thermal shutdown, the FAULT open-collector output is
pulled low (turned on).
Overcurrent Fault Sense Circuit
+
–
+
–
+
–
V
S
V
REF
V
SENSE
I
LOAD
I
REF
SENSE
To Fault Latch
Matched
REF
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
8
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Package LW, 20-pin SOIC-W
21
20
21
20
A
2.65 MAX
C
SEATING
PLANE
C0.10
20X
ATerminal #1 mark area
GAUGE PLANE
SEATING PLANE B
2.25
0.65
9.50
1.27
PCB Layout Reference View
For Reference Only
Dimensions in millimeters
(Reference JEDEC MS-013 AC)
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
BReference pad layout (reference IPC SOIC127P1030X265-20M)
All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances
1.27
0.25
0.20 ±0.10
0.41 ±0.10
12.80±0.20
10.30±0.33
7.50±0.10
4° ±4
0.27 +0.07
–0.06
0.84 +0.44
–0.43
DABIC
-
5 8-Channel Source Driver
with Overcurrent Protection
UDN2987x-6
9
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
For the latest version of this document, visit our website:
www.allegromicro.com
Copyright ©2006-2012, Allegro MicroSystems, Inc.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be required to per-
mit improvements in the per for mance, 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’s products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the
failure of that life support device or system, or to affect the safety or effectiveness of that device or system.
The in for ma tion in clud ed herein is believed to be ac cu rate and reliable. How ev er, Allegro MicroSystems, Inc. assumes no re spon si bil i ty for its use;
nor for any in fringe ment of patents or other rights of third parties which may result from its use.
Revision History
Revision Revision Date Description of Revision
Rev. 6 April 30, 2012 Update product availability
