L6223 Datasheet, PDF (15/33 Pages) STMicroelectronics – DMOS PROGRAMMABLE HIGH SPEED UNIPOLAR STEPPER MOTOR DRIVER

L6223
Dual Device Application
Fig. 16 shows how to drive one unipolar stepper
motor by means of two L6223 Each device drives
one phase of the motor. This permits doubling of
the phase current. Since in this configuration
each sense resistor controls the phase current (in
Single only one sense resistor controls the total
motor current), we have: RS = (Vref/Ip) where Vref
is the voltage reference and Ip the phase current
in the Dual that is coincident with the chopping
current. The configuration in the figure shows the
only possible way to parallel two L6223. The use
of another configuration can cause serious de-
mage to the IC during the programming. The
waveforms required to drive the motor in half/full
step are shown in Fig. 17 and 18: as it can be
seen, the two L6223 are in SIMPLIFIED MODE
OPERATING configuration. The half step drive
can be achieved by driving the inputs IN3 which
are ENABLE inputs.
Figure 17: Inputs for Half Step drive dual device SMO.
Figure 18: Inputs for Full Step drive single device SMO.
Dot Matrix Printer Motor Driver
Fig. 19 shows how to drive the paper feed and
the carriage motors by means of 3 L6223 using a
very low wire number. The carriage motor is
driven by two paralleled L6223, the paper feed
motor, which requires a lower current, uses one
L6223. The three ICs are working in SIMPLIFIED
MODE OPERATING. The inputs IN1-IN2, IN3 are
driven as previously seen (Single and Dual De-
vice configuration). The inputs IN4 and DA/CLEV
are grounded so that the ICs work in reduced cur-
rent levels. This means L6223 can select seven
current levels through programming: four in
closed loop and three in open loop. The input
DA/OPLO is used to load the programming data;
only the device in PROGRAMMING MODE is pro-
grammed. The two paralleled L6223 can deliver
up to 2A/phase while the single L6223, 1A/phase.
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