L6219R_06 STMICROELECTRONICS [STMicroelectronics], L6219R_06 Datasheet - Page 10

• Manufacturer Part Number: L6219R_06
• Description: Stepper motor driver
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Functional description
3
3.1
3.2
3.3
10/16
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
winding 2.
The current can also be switched off completely
Input Logic (I
The current level in the motor winding is selected with these inputs. (See
If any of the logic inputs is left open, the circuit will treat it has a high level input.
Table 5.
Phase
This input determines the direction of current flow 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 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
comparators.Only one comparator is active at a time. It is activated by the input logic
according to the current level chosen with signals I
the sensing resistor RS.When the current has increased so that the voltage across R
becomes higher than the reference voltage on the other comparator input, the comparator
goes high, which triggers the pulse generator.
The max peak current Imax can be defined by:
See figures
versus V
I
H
H
L
L
0
s
supply.
I
H
H
L
L
Figure
1
Input logic current level
No Current
Low current 1/3 I
Medium current 2/3 I
Maximum current I
3,
0
4
and I
and
5
1
for maximum allowable output current and reference voltage
)
O
max
O
O
max
max
I
max
=
S
------------- -
10R
Current Level
V
), a low pass filter (R
ref
o
s
and I
01
- I
1
.The motor current flows through
11
for winding 1 and I
C
, C
C
Figure
) and three
02
4)
- I
L6219R
12
S
for