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Электронный компонент: L6219DSA

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L6219DSA
STEPPER MOTOR DRIVER FOR AUTOMOTIVE RANGE
ABLE TO DRIVE BOTH WINDINGS OF BIPO-
LAR STEPPER MOTOR
OUTPUT CURRENT UP TO 750mA EACH
WINDING
WIDE VOLTAGE RANGE 10V TO 46V
HALF-STEP, FULL-STEP AND MICROSTEPP-
ING MODE
BUILT-IN PROTECTION DIODES
INTERNAL PWM CURRENT CONTROL
LOW OUTPUT SATURATION VOLTAGE
DESIGNED FOR UNSTABILIZED MOTOR
SUPPLY VOLTAGE
INTERNAL THERMAL SHUTDOWN
DESCRIPTION
The L6219DSA is a bipolar monolithic integrated
circuits intended to control and drive both winding
of a bipolar stepper motor or bidirectionally con-
trol two DC motors.
The L6219DSA with a few external components
form a complete control and drive circuit for LS-
TTL or microprocessor controlled stepper motor
system.
The power stage is a dual full bridge capable of
sustaining 46V and including four diodes for cur-
rent recirculation.
A cross conduction protection is provided to avoid
simultaneous cross conduction during switching
current direction.
An internal pulse-width-modulation (PWM) con-
trols the output current to 750mA with peak start-
up 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 direc-
tion.
A thermal protection circuitry disables the outputs
if the chip temperature exceeds safe operating
limits.
November 1998
SO20+2+2
ORDERING NUMBER: L6219DSA
BLOCK DIAGRAM
1/8
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 Resistor
4;22
COMPARATOR
INPUT
Input connected to the comparators. The voltage across the sense resistor is
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
T
C
T
(t
off
= 1.1 R
T
C
T
). See fig. 1.
5;21
OUTPUT B
Output Connection. The output stage is a "H" bridge formed by four transistors and
four diodes suitable for switching applications.
6;19
GROUND
See pins 7;18
7;18
GROUND
Ground Connection. With pins 6 and 19 also conducts heat from die to printed circuit
copper.
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 of the
comparators to set the current level. Current also depends on the sensing resistor and
reference voltage. See Funcional Description.
10;16
PHASE
This TTL-compatible logic inputs sets the direction of current flow through the 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 circuits during switching.
11;15
REFERENCE
VOLTAGE
A voltage applied to this pin sets the reference voltage of the comparators, this
determining the output current (also thus depending on R
s
and the two inputs INPUT
0 and INPUT 1).
12;14
RC
A parallel RC network connected to this pin sets the OFF time of the higher power
transistors. The pulse generator is a monostable triggered by the output of the
comparators (t
off
= 1.1 R
T
C
T
).
13
V
ss
- LOGIC SUPPLY Supply Voltage Input for Logic Circuitry
24
Vs - LOAD SUPPLY
Supply Voltage Input for the Output Stages.
Note: ESD on GND, V
S
, V
SS
, OUT 1A and OUT 2A is guaranteed up to 1.5KV (Human Body Model, 1500
, 100pF).
PIN CONNECTION (Top view)
L6219DSA
2/8
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
S
Supply Voltage
50
V
I
o
Output Current (peak)
1
A
I
o
Output Current (continuous)
0.75
A
V
SS
Logic Supply Voltage
7
V
V
IN
Logic Input Voltage Range
-0.3 to +7
V
V
sense
Sense Output Voltage
1.5
V
T
J
Junction Temperature
+150
C
T
op
Operating Temperature Range
-40 to 125
C
T
stg
Storage Temperature Range
-55 to +150
C
THERMAL DATA
Symbol
Description
Value
Unit
R
thj-case
R
thj-amb
Thermal Resistance Junction-case
Max.
Thermal Resistance Junction-ambient
Max.
18
75 (*)
C/W
C/W
(*) With minimized copper area.
ELECTRICAL CHARACTERISTICS (T
j
= -40 to 125
C, V
S
= 46V, V
SS
= 4.75V to 5.25V, V
REF
= 5V; un-
less otherwise specified) See fig. 3.
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
OUTPUT DRIVERS (OUT
A
or OUT
B
)
V
S
Motor Supply Range
10
46
V
I
CEX
Output Leakage Current
VS = 52V
V
OUT
= 50V
V
S
= 52V
V
OUT
= 1V
-200
200
A
A
V
CE(sat)
Output Saturation Voltage
Sink Driver, I
OUT
= +500mA
Sink Driver, I
OUT
= +750mA
Source Driver, I
OUT
= -500mA
Source Driver, I
OUT
= -750mA
0.75
1.15
1.6
1.8
V
V
V
V
V
F
Clamp Diode Forward Voltage
High stage I
F
=750mA
Low stage I
F
=750mA
1.7
1.6
V
V
I
S(on)
Driver Supply Current
Both Bridges ON, No Load
17
mA
I
S(off)
Driver Supply Current
Both Bridges OFF
12
mA
CONTROL LOGIC
V
IN(H)
Input Voltage
All Inputs
2.4
V
V
IN(L)
Input Voltage
All Inputs
0.8
V
I
IN(H)
Input Current
VIN = 2.4V
<1
20
A
I
IN(L)
Input Current
VIN = 0.84V
-3
-200
A
V
REF
Reference Voltage
Operating
1.5
7.5
V
I
SS(ON)
Total Logic Supply Current
I
o
= I
1
= 0.8V, No Load
76
mA
I
SS(OFF)
Total Logic Supply Current
I
o
= I
1
= 2.4V, No Load
15
mA
COMPARATORS
V
REF
/ V
sense
Current Limit Threshold (at trip
point
I
o
= I
1
= 0.8V
9.5
10
10.5
I
o
= 2.4V, I
1
= 0.8V
13.5
15
16.5
I
o
= 0.8V, I
1
= 2.4V
25.5
30
34.5
t
off
Cutoff Time
Rt = 56K
C
t
= 820pF
50
s
t
d
Turn Off Delay
Fig. 1
1
s
L6219DSA
3/8
FUNCTIONAL DESCRIPTION
The circuit is intended to drive both windings of a
bipolar stepper motor.
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
01
- I
11
for winding 1 and
I
02
- I
12
for winding 2.
The current can also be switched off completely
Input Logic (I
0
and I
1
)
The current level in the motor winding is selected
with these inputs. (See fig. 2)
If any of the logic inputs is left open, the circuit will
treat it has a high level input.
I
o
I
1
Current Level
H
L
H
L
H
H
L
L
No Current
Low Current 1/3 I
o
max
Medium Current 2/3 I
o
max
Maximum Current I
o
max
Phase
This input determines the direction of current flow
in the windings, depending on the motor connec-
tions. 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 during phase-shift.
High level on the PHASE input causes the motor
current flow from Out A through the winding to
Out B
Current Sensor
This part contains a current sensing resistor (R
S
),
a low pass filter (R
C
, C
C
) and three comparators.
Only one comparator is active at a time. It is acti-
vated by the input logic according to the current
level chosen with signals I
o
and I
1
.
The motor current flows through the sensing re-
sistor R
S
.
When the current has increased so that the volt-
age across R
S
becomes higher than the refer-
ence voltage on the other comparator input, the
comparator goes high, which triggers the pulse
generator.
The max peak current I
max
can be defined by:
I
max
=
V
ref
10 R
s
Figure 1
ELECTRICAL CHARACTERISTICS (Continued)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
PROTECTION
T
J
Thermal Shutdown Temperature
-
170
-
C
L6219DSA
4/8
Single-pulse Generator
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
off
, which is determined by the time compo-
nents R
t
and C
t
.
t
off
= 1.1
R
t
C
t
The single pulse switches off the power feed to
the motor winding, causing the winding current to
decrease during t
off
.
If a new trigger signal should occur during t
off
, it is
ignored.
Output Stage
The output stage contains four Darlington transis-
tors (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 constant current through the winding.
It should be noted however, that is not permitted
to short circuit the outputs.
Internal circuitry is added in order to increase the
accuracy of the motor current particularly with low
current levels.
Figure 2: Principle Operating Sequence
L6219DSA
5/8