Using PWM to minimize power dissipation and maximize load
efficiency, the UDN2962W dual driver is recommended for impact
printer solenoids and stepper motors. It is comprised of two source/
sink driver pairs rated for continuous operation to
3 A. It can be
connected to drive two independent loads or a single load in the full-
bridge configuration. Both drivers include output clamp/flyback
diodes, input gain and level shifting, a voltage regulator for single-
supply operation, and pulse-width modulated output-current control
circuitry. Inputs are compatible with most TTL, DTL, LSTTL, and
low-voltage CMOS or PMOS logic.
The peak output current and hysteresis for each source/sink pair is
set independently. Output current, threshold voltage, and hysteresis are
set by the user's selection of external resistors. At the specified output-
current trip level, the source driver turns off. The internal clamp diode
then allows current to flow without additional input from the power
supply. When the lower current trip point is reached, the source driver
turns back on.
The UDN2962W is in a 12-pin single in-line power-tab package.
The tab is at ground potential and needs no insulation. For high-
current or high-frequency applications, external heat sinking may be
required.
FEATURES
I 4 A Peak Output
I 45 V Min. Sustaining Voltage
I Internal Clamp Diodes
I TTL/PMOS/CMOS Compatible Inputs
I High-Speed Chopper
Dwg. No. D-1001
2962
DUAL SOLENOID/MOTOR DRIVER
--PULSE-WIDTH MODULATED CURRENT CONTROL
ABSOLUTE MAXIMUM RATINGS
at T
J
+150C
Supply Voltage, V
CC
. . . . . . . . . . . . . . 45 V
Peak Output Current, I
OUT
. . . . . . . . .
4 A
Input Voltage Range,
V
IN
. . . . . . . . . . . . . . . - 0.3 V to +7.0 V
Package Power Dissipation,
P
D
. . . . . . . . . . . . . . . . . . . See Graph
Operating Temperature Range,
T
A
. . . . . . . . . . . . . . . . -20
C to +85
C
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . . -55
C to +150
C
NOTE: Output current rating may be limited by
duty cycle, ambient temperature, and heat
sinking. Under any set of conditions, do not
exceed the specified peak current and a junction
temperature of +150
C.
Always order by complete part number:
UDN2962W .
THS
IN
SENSE
SINK
SOURCE
B
B
B
B
B
GROUND
IN
A
SENSE
A
SINK
A
SOURCE
A
THS
A
V
CC
LOGIC
12
11
10
9
8
7
6
5
4
3
2
1
LOGIC
Data Sheet
29319.12A
2962
DUAL PWM
SOLENOID/MOTOR DRIVER
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
FUNCTIONAL BLOCK DIAGRAM
(ONE OF TWO DRIVERS)
Dwg. No. D-1002
TRUTH TABLE
SOURCE
SINK
V
IN
V
SENSE
DRIVER
DRIVER
High
NA
Off
Off
Low
<V
THS
/10
On
On
Low
>V
THS
/10
Off
On
V
CC
SOURCE
LOAD
SINK
SENSE
R
S
(TYP.0.1 )
V
REF
R
H
R
T
THS
-10
+
_
GND
IN
50
75
100
125
150
10
6
4
2
0
ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS
TEMPERATURE IN
C
8
25
R = 2.0
C/W
JT
Dwg. GP-012B
FREE AIR, R = 38
C/W
JA
3.0
C/W HEAT SINK
R = 5.0
C/W
JA
12
C/W HEAT SINK
R = 14
C/W
JA
W
Copyright 1986, 2000 Allegro MicroSystems, Inc.
2962
DUAL PWM
SOLENOID/MOTOR DRIVER
www.allegromicro.com
ELECTRICAL CHARACTERISTICS at T
A
= +25
C, T
J
+150
C, V
CC
= 45 V, V
SENSE
= 0 V (unless
otherwise noted).
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ. Max.
Units
Supply Voltage Range
V
CC
Operating
20
--
45
V
Output Drivers
Output Leakage Current
I
CEX
V
IN
= 2.4 V, V
SOURCE
= 0 V
--
<-1.0
-100
A
V
IN
= 2.4 V, V
SINK
= 45 V
--
<1.0
100
A
Output Saturation Voltage
V
CE(SAT)
Source Drivers, I
LOAD
= 3.0 A
--
2.1
2.3
V
Source Drivers, I
LOAD
= 1.0 A
--
1.7
2.0
V
Sink Drivers, I
LOAD
= 3.0 A
--
1.7
2.0
V
Sink Drivers, I
LOAD
= 1.0 A
--
1.1
1.3
V
Output Sustaining Voltage
V
CE(sus)
I
OUT
=
3.0 A, L = 3.5 mH
45
--
--
V
Output Current Regulation
I
OUT
V
THS
= 0.6 V to 1.0 V, L = 3.5 mH
--
--
25
%
V
THS
= 1.0 V to 2.0 V, L = 3.5 mH
--
--
10
%
V
THS
= 2.0 V to 5.0 V, L = 3.5 mH
--
--
5.0
%
Clamp Diode Forward Voltage
V
F
I
F
= 3.0 A
--
1.7
2.0
V
Output Rise Time
t
r
I
LOAD
= 3.0 A, 10% to 90%, Resistive Load
--
0.5
1.0
s
Output Fall Time
t
f
I
LOAD
= 3.0 A, 90% to 10%, Resistive Load
--
0.5
1.0
s
Control Logic
Logic Input Voltage
V
IN(1)
2.4
--
--
V
V
IN(0)
--
--
0.8
V
Logic Input Current
I
IN(1)
V
IN
= 2.4 V
--
1.0
10
A
I
IN(0)
V
IN
= 0.8 V
--
-20
-100
A
I
THS(ON)
V
THS
500 mV, V
SENSE
V
THS
/10.5
--
-2.0
--
A
I
THS(HYS)
V
SENSE
V
THS
/ 9.5, V
THS
= 0.6 V to 5.0 V
140
200
260
A
V
THS
/V
SENSE
Ratio
--
At Trip Point, V
THS
= 2.0 V to 5.0 V
9.5
10
10.5
--
Supply Current
l
CC
V
IN
= 2.4 V, Outputs Off
--
8.0
12
mA
V
IN
= 0.8 V, Outputs Open
--
25
40
mA
Propagation Delay Time
t
pd
50% V
IN
to 50% V
OUT
, Turn Off
--
--
2.5
s
50% V
IN
to 50% V
OUT
, Turn On
--
--
3.0
s
100% V
SENSE
to 50% V
OUT
*
--
--
3.0
s
* Where V
SENSE
V
THS
/9.5
NOTE: Negative current is defined as coming out of (sourcing) the specified device pin.
(Total Device)
(Resistive Load)
2962
DUAL PWM
SOLENOID/MOTOR DRIVER
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
CIRCUIT DESCRIPTION
AND APPLICATIONS INFORMATION
The UDN2962W high-current driver is intended for use as a
free-running, pulse-width modulated solenoid driver.
Circuit Description. In operation, the source and sink drivers are
both turned on by a low level at the input. The load current rises with
time as a function of the load inductance, total circuit resistance, and
supply voltage and is sensed by the external sense resistor (R
S
).
When the load current reaches the trip point (I
TRIP
), the comparator
output goes high and turns off the source driver. The actual load
current will peak slightly higher than I
TRIP
because of the internal logic
and switching delays.
After the source driver is turned off, the load current continues to
circulate through the sink driver and an internal ground clamp diode.
The rate of current decay is a function of the load inductance and total
circuit resistance.
An internal constant current sink reduces the trip point (hysteresis)
until the decaying load current reaches the lower threshold, when the
comparator output goes low and the source driver is again turned on.
Load current is again allowed to rise to the trip point and the cycle
repeats.
Maximum load current and hysteresis is determined by the user.
Determining Maximum Load Current and Hysteresis. Trip
current (I
TRIP
) is determined as a function of resistance R
S
and the
threshold voltage, V
THS
:
V
THS
I
TRIP
=
10 R
S
where V
THS
= 10 x V
SENSE
= 0.6 V to 5.0 V.
Hysteresis percentage (H) is determined by resistance R
H
and is
independent of the load current:
R
H
H =
50 x V
REF
The chopping frequency is asynchronous and a function of the
system and circuit parameters, including load inductance, supply
voltage, hysteresis setting, and switching speed of the driver.
Resistance R
T
is determined as:
R
H
V
THS
R
T
=
V
REF
V
THS
Note that if V
THS
= V
REF,
then R
T
=
.
Circuit Layout. To prevent interaction
between channels, each of the two high-level
power ground returns (the low side of the
sense resistors) must be returned independ-
ently to the low-level signal ground (pin 1).
The circuit common (pin 1) can then be
routed to the system ground.
The printed wiring board should utilize a
heavy ground plane. For optimum perform-
ance, the driver should be soldered directly
into the board.
The power supply (V
CC
) should be
decoupled with an electrolytic capacitor
(
10 F) as close as possible to pin 7.
TYPICAL WAVESHAPES
=
VIN
V
SINK
VSOURCE
I
LOAD
V
THS
V
CC
GND
VCC
I TRIP S THS
GND
R
V
10
Dwg. WP-006
3
7
10
+
R
S
R
S
SYSTEM GROUND
SUPPLY
Dwg. OP-001
1
2962
DUAL PWM
SOLENOID/MOTOR DRIVER
www.allegromicro.com
APPLICATIONS INFORMATION
RESISTOR R
H
VALUE
AS A FUNCTION OF HYSTERESIS
RESISTOR R
T
VALUE
AS A FUNCTION OF PEAK LOAD CURRENT
Dwg. No. A-12,417
Dwg. No. A-12,416
Dwg. No. D-1004
25
20
15
10
5
0
0
R
IN
k
H
20
40
60
80
100
HYSTERESIS, H, IN PERCENT
V = 5 V
REF
NOTE: Each of the drivers includes an internal logic delay to prevent
potentially destructive crossover currents within the driver during phase
changes. However, never simultaneously enable both inputs in the full-
bridge configurations: A destructive short-circuit to ground will result.
R
H
AND R
T
DETERMINE HYSTERESIS AND PEAK CURRENT
25
20
15
10
5
0
0
R
IN
k
T
3.0
1.0
2.5
3.5
4.0
LOAD CURRENT, I , IN AMPERES
0.5
1.5
2.0
MAX
H=
25
%
H=20%
H=
15%
H=1
0%
H=5%
V = 5V
REF
S
R = 0.1
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