Datasheet UDN2916A Datasheet (SGS Thomson Microelectronics)

ABLE TO DRIVE BOTH WINDINGS OF BIPO­LARSTEPPERMOTOR

OUTPUT CURRENT UP TO 750mA EACH
WINDING

WIDEVOLTAGE RANGE10V TO 50V
HALF-STEP, FULL-STEP AND MICROSTEPP-

INGMODE
BUILT-INPROTECTIONDIODES
INTERNAL PWMCURRENTCONTROL
LOW OUTPUT SATURATIONVOLTAGE
DESIGNED FOR UNSTABILIZED MOTOR

SUPPLYVOLTAGE
INTERNAL THERMAL SHUTDOWN

DESCRIPTION

The UDN2916A is a bipolar monolithic integrated
circuits intended to control and drive both winding
of a bipolar stepper motor or bidirectionally con­trol two DC motors.
The UDN2916A with a few external components
form a complete control and drive circuit for LS­TTL or microprocessor controlled stepper motor
system.
The power stage is a dual full bridge capable of
sustaining 50V and including four diodes for cur­rent recirculation.

UDN2916A

STEPPER MOTOR DRIVER

ADVANCE DATA

Powerdip 20+2+2

ORDERING NUMBER: UDN2916A

A cross conduction protection is provided to avoid
simultaneous cross conduction during switching
currentdirection.
An internal pulse-width-modulation (PWM) con­trols the output current to 750mA with peak start­up current up to 1A.
Wide range of current control from 750mA (each
bridge) is permitted by means of two logic inputs
and an external voltage reference. A phase input
to each bridge determines the load current direc­tion.
A thermal protection circuitry disables the outputs
if the chip temperature exceeds safe operating
limits.

BLOCK DIAGRAM

November 1991

ThAdvanced information on a new product now in development or undergoing evaluation. Details are subject to change withoutnotice.

1/8

UDN2916A

PIN CONNECTION (Top view)

PIN FUNCTIONS

N° Name Function

1;2 OUTPUT A See pins 5;21

3;23 SENSE RESISTOR Connection to Lower Emitters of Output Stage for Insertion of Current Sense

4;22 COMPARATOR INPUT Input connected to the comparators. The voltage across the sense resistor is

5;21 OUTPUT B Output Connection. The output stageis a ”H” bridgeformed by four

6;19 GROUND See pins 7;18
7;18 GROUND Ground Connection. With pins 6 and 19 also conducts heat from die to

8;20 INPUT 0 See INPUT 1 (pins 9;17)
9;17 INPUT 1 These pins and pins 8;20 (INPUT 0) are logic inputs which select the outputs

10;16 PHASE This TTL-compatible logic inputs sets the direction of current flow through the

11;15 REFERENCE VOLTAGE A voltage applied to this pin sets the reference voltage of the comparators,

12;14 RC A parallel RC network connected to this pin sets the OFF time of the higher

13 V
24 V

- LOGIC SUPPLY Supply Voltage Input for Logic Circuitry

ss

- LOAD SUPPLY Supply Voltage Input for the Output Stages.

S

Resistor

feedback to this input throught the low pass filter RC CC. The higher power
transistors are disabled when the sense voltage exceeds the reference
voltage of the selected comparator. When this occurs the current decays for
a time set by R

TCT(toff

= 1.1 RTCT). See fig. 1.

transistors and four diodes suitable for switching applications.

printed circuit copper.

of the comparators to set the current level. Current also depends on the
sensing resistor and reference voltage. See Funcional Description.

load. A high level causes current to flow from OUTPUT A (source) to
OUTPUT B (sink). A schmitt trigger on this input provides good noise
immunity and a delay circuit prevents output stage short circuitsduring
switching.

this determining the outputcurrent (also thus depending on R

and the two

s

inputs INPUT 0 and INPUT 1).

power transistors. The pulse generator is a monostable triggered by the
output of the comparators (t

= 1.1 RTCT).

off

2/8

UDN2916A

ABSOLUTE MAXIMUMRATINGS

Symbol Parameter Value Unit

V

V

V

V

sense

T

T

T

THERMAL DATA

Symbol Description Value Unit

R

thj-case

R

thj-ambient

Supply Voltage 50 V

S

Output Current (peak) ±1A

I

o

Output Current (continuous) ±0.75 A

I

o

Logic Supply Voltage 7 V

SS

Logic Input Voltage Range -0.3 to +7 V

IN

Sense OutputVoltage 1.5 V
Junction Temperature +150 °C

J

Operating Temperature Range 0 to 70 °C

op

Storage Temperature Range -55 to +150 °C

stg

Thermal Resistance Junction-case
Thermal Resistance Junction-ambient

Max
Max

14
60

°C/W
°C/W

ELECTRICALCHARACTERISTICS (T

= 5V; unless otherwise specified) See fig. 3.

V

REF

amb

=25°C,T

≤ 70°C,VS= 50V, VSS= 4.75V to 5.25V,

tab

Symbol Parameter Test Condition Min. Typ. Max. Unit

OUTPUTDRIVERS(OUTAor OUTB)

I

V

CE(sat)

I

S(on)

I

S(off)

V

CEX

I

V

Motor Supply Range 10 50 V

S

Output Leakage Current V

Output Saturation Voltage Sink Driver, I

Clamp Diode Leakage Current VR = 50V - <1 50 µA

R

Clamp Diode Forward Voltage Sink Diode

F

=Vs

OUT

V

=0

OUT

Sink Driver, I

OUT = +750mA

Source Driver, I
Source Driver, I

Source Diode I

= +500mA

OUT

= -500mA

OUT

= -750mA

OUT

F =750mA

-

-

-

-

-

-

<1

<-1

0.3

0.7

1.1

1.3

1

1
Driver Supply Current Both BridgesON, No Load - 8 15 mA
Driver Supply Current Both Bridges OFF - 6 10 mA

50

-50

0.6
1

1.4

1.6

1.5

1.5

CONTROLLOGIC

V

IN(H)

V

IN(L)

I

IN(H)

I

IN(L)

V

REF

I

SS(ON)

I

SS(OFF)

Input Voltage All Inputs 2.4 - - V
Input Voltage All Inputs - - 0.8 V
Input Current VIN = 2.4V - <1 20 µA
Input Current VIN = 0.84V - -3 -200 µA
Reference Voltage Operating 1.5 - 7.5 V
Total Logic Supply Current Io=I1= 0.8V, No Load - 54 64 mA
Total Logic Supply Current Io =I1= 2.4V, No Load - 10 14 mA

COMPARATORS

µA
µA

V
V
V
V

V
V

V

REF/Vsense

t

off

t

d

Current Limit Threshold (at trip
point

Cutoff Time Rt = 56KΩ Ct= 820pF - 50 s
Turn Off Delay Fig. 1 - 1 s

Io =I1= 0.8V 9.5 10 10.5 -

= 2.4V, I1= 0.8V 13.5 15 16.5 -

I

o

= 0.8V, I1= 2.4V 25.5 30 34.5 -

I

o

µ
µ

3/8

UDN2916A

ELECTRICALCHARACTERISTICS (Continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

PROTECTION

T

J

Figure1

Thermal Shutdown Temperature - 170 - °C

FUNCTIONAL DESCRIPTION

The circuit is intended to drive both windings of a
bipolar steppermotor.
The peak current control is generated through
switch mode regulation.
There is a choice of three different current levels
with the two logic inputs I
I

02-I12

for winding2.

01-I11

for winding 1 and

The current can also be switchedoff completely

InputLogic (I

and I1)

0

The current level in the motor winding is selected
with these inputs. (See fig. 2)
If anyof the logic inputs is left open, thecircuit will
treatit has a high level input.

I

o

H

L

H

L

I

1

No Current

H

Low Current 1/3 I

H

L

Medium Current 2/3 I

L

Maximum Current I

Current Level

max

o

o

max

o

max

Phase

This input determines the direction of current flow

4/8

in the windings, depending on the motor connec­tions. The signal is fed through a Schmidt-trigger
for noise immunity, and through a time delay in
order to guarantee that no short-circuit occurs in
the output stage duringphase-shift.
High level on the PHASE input causes the motor
current flow from Out A through the winding to
OutB

CurrentSensor

This part contains a current sensing resistor (R
a lowpass filter (R

) and threecomparators.

C,CC

S

Only one comparator is active at a time. It is acti­vated by the input logic according to the current
levelchosenwith signals I

and I1.

o

The motor current flows through the sensing re­sistor R

.

S

When the current has increased so that the volt­age across R

becomes higher than the refer-

S

ence voltage on the other comparator input, the
comparator goes high, which triggers the pulse
generator.
Themax peak current I

I

max

Single-pulseGenerator

canbe definedby:

max

V

ref

=

10 R

s

),

Figure2: PrincipleOperatingSequence

UDN2916A

The pulse generator is a monostable triggered on
the positive going edge of the comparator output.
The monostable output is high during the pulse
time, t
nents R

, which is determined by thetime compo-

off

andCt.

t

=1.1 •RtC

t

off

t

The single pulse switches off the power feed to
the motor winding, causing the winding current to
decreaseduring t
If a new trigger signal shouldoccur during t

off

.

,itis

off

ignored.

Output Stage

The output stage contains four Darlington transis­tors (source drivers) four saturated transistors
(sink drivers) and eight diodes, connected in two
H bridge.
The source transistors are used to switch the
power supplied to the motor winding, thus driving
a constantcurrent through the winding.
It should be noted however, that is not permitted
to short circuit the outputs.
Internal circuitry is added in order to increse the
accuracyof the motor current particularly with low
currentlevels.

V

S,VSS,VRef

5/8

UDN2916A

The circuit will stand any order of turn-on or turn­off the supply voltages V

and VSS. Normal dV/dt

S

valuesare thenassumed.
Preferably, V
power-onand power-off if V

should be tracking VSSduring

Ref

is established.

S

APPLICATIONINFORMATIONS (Note 1)
Some stepper motors are notdesignedfor contin­uous operation at maximum current. As the circuit
drives a constant current through the motor, its
temperature might increase exceedingly both at
low and high speed operation.
Also, some stepper motors have such high core
losses that they are not suited for switch mode
currentregulation.
Unused inputs should be connected to proper
voltagelevelsin order to get the highest noise im-

Figure3: TypicalApplicationCircuit.

munity.
As the circuit operates with switch mode current

regulation, interference generation problems
mightarise in someapplications. A goodmeasure
might then be to decouple the circuit with a 100nF
capacitor, located near the package between
powerline and ground.
The ground lead between R

, and circuit GND

s

shouldbe kept as short as possible.
A typical Application Circuit is shown in Fig. 3.
Notethat C

must be NPO type or similarelse.

t

To sense the winding current, paralleled metal
film resistors are recommended (R

)

s

Note 1 - Other information is available as ”Smart
PowerDevelopment System”:HWPC2916A.

6/8

DIP24 (20+2+2) MECHANICAL DATA

UDN2916A

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

a1 0.38 0.015

b 0.41 0.51 0.016 0.020
b1 0.20 0.25 0.30 0.008 0.010 0.012
b2 1.40 1.52 1.65 0.055 0.060 0.065

D 30.23 1.19
E 7.62 0.300

e 2.54 0.100

F 6.86 0.270

I 4.32 0.170

L 3.18 0.125

mm inch

7/8

UDN2916A

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may resultfrom its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications men­tioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without ex­press written approval of SGS-THOMSON Microelectronics.

 1994 SGS-THOMSON Microelectronics - All RightsReserved

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