L6223A ST Microelectronics, Inc., L6223A Datasheet - Page 15

• Manufacturer Part Number: L6223A
• Description: Dmos Programmable High Speed Unipolar Stepper Motor Driver
• Manufacturer: ST Microelectronics, Inc.

Dual Device Application
Fig. 16 shows how to drive one unipolar stepper
motor by means of two L6223A Each device
drives one phase of the motor. This permits dou-
bling of the phase current. Since in this configura-
tion each sense resistor controls the phase cur-
rent (in Single only one sense resistor controls
the total motor current), we have: R
where V
phase current in the Dual that is coincident with
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 L6223A using
a very low wire number. The carriage motor is
driven by two paralleled L6223A, the paper feed
motor, which requires a lower current, uses one
L6223A. The three ICs are working in SIMPLI-
FIED MODE OPERATING. The inputs IN1-IN2,
IN3 are driven as previously seen (Single and
Dual Device configuration). The inputs IN4 and
ref
is the voltage reference and Ip the
S
= (V
ref
/Ip)
the chopping current. The configuration in the fig-
ure shows the only possible way to parallel two
L6223A. The use of another configuration can
cause serious demage to the IC during the pro-
gramming. 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 L6223A are in SIMPLI-
FIED MODE OPERATING configuration. The half
step drive can be achieved by driving the inputs
IN3 which are ENABLE inputs.
DA/CLEV are grounded so that the ICs work in
reduced current levels. This means L6223A can
select seven current levels through programming:
four in closed loop and three in open loop. The in-
put DA/OPLO is used to load the programming
data; only the device in PROGRAMMING MODE
is programmed. The two paralleled L6223A can
deliver up to 2A/phase while the single L6223A,
1A/phase.
L6223A
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