A3967SLB Allegro Microsystems Inc, A3967SLB Datasheet - Page 6

• Manufacturer Part Number: A3967SLB
• Description: IC MOTOR DRIVER PWM FULL 24SOIC
• Manufacturer: Allegro Microsystems Inc

Specifications of A3967SLB

• Applications: Stepper Motor Driver
• Number Of Outputs: 1
• Current - Output: ±750mA
• Voltage - Load: 4.75 V ~ 30 V
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Operating Current: 65mA
• Operating Temperature Classification: Commercial
• Package Type: SOIC W
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

RC Blanking. In addition to the fi xed off-time of the
PWM control circuit, the C
tor blanking time. This function blanks the output of the
current-sense comparator when the outputs are switched by
the internal current-control circuitry. The comparator out-
put is blanked to prevent false overcurrent detection due
to reverse recovery currents of the clamp diodes, and/or
switching transients related to the capacitance of the load.
The blank time t
Enable Input (ENABLE). This active-low input enables
all of the outputs. When logic high the outputs are dis-
abled. Inputs to the translator (STEP, DIRECTION, MS
MS
state.
Shutdown. In the event of a fault (excessive junction
temperature) the outputs of the device are disabled until
the fault condition is removed. At power up, and in the
event of low V
circuit disables the drivers and resets the translator to the
home state.
Sleep Mode (SLEEP). An active-low control input used
to minimize power consumption when not in use. This dis-
ables much of the internal circuitry including the outputs.
A logic high allows normal operation and startup of the
device in the home position.
A3967
2
) are all active independent of the ENABLE input
CC
BLANK
, the under-voltage lockout (UVLO)
Typical output saturation voltages show-
ing Satlington sink-driver operation.
t
BLANK
can be approximated by:
T
= 1400C
component sets the compara-
T
Functional Description (cont’d)
Microstepping Driver with Translator
1
,
Percent Fast Decay Input (PFD). When a STEP input
signal commands a lower output current from the previous
step, it switches the output current decay to either slow-,
fast-, or mixed-decay depending on the voltage level at the
PFD input. If the voltage at the PFD input is greater than
0.6V
the PFD input is less than 0.21V
selected. Mixed decay is between these two levels.
Mixed Decay Operation. If the voltage on the PFD in-
put is between 0.6V
ate in mixed-decay mode depending on the step sequence
(see fi gures). As the trip point is reached, the device will
go into fast-decay mode until the voltage on the RC termi-
nal decays to the voltage applied to the PFD terminal. The
time that the device operates in fast decay is approximated
by:
switch to slow-decay mode for the remainder of the fi xed
off-time period.
2.5
2.0
1.5
1.0
0.5
After this fast decay portion, t
0
CC
then slow-decay mode is selected. If the voltage on
SINK DRIVER
200
T
A
t
= +25°C
FD
OUTPUT CURRENT IN MILLIAMPERES
= R
300
CC
T
and 0.21V
C
T
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
In (0.6V
4
0
0
CC
CC
FD
CC
then fast-decay mode is
, the bridge will oper-
500
, the device will
/V
PFD
SOURCE DRIVER
)
600
Dwg. GP-064-1A
7
0
0
6