A3982
DMOS Stepper Motor Driver with Translator
Package LB
OUT2A
SENSE2
VBB2
OUT2B
ENABLE
PGND
PGND
CP1
CP2
1
2
3
4
5
24 OUT1A
23 SENSE1
22 VBB1
21 OUT1B
20 DIR
The A3982 is a complete stepper motor driver with built-in translator
for easy operation. It is designed to operate bipolar stepper motors in
full- and half-step modes, with an output drive capacity of up to 35 V
and 鹵2 A. The A3982 includes a fixed off-time current regulator which
has the ability to operate in Slow or Mixed decay modes.
The translator is the key to the easy implementation of the A3982.
Simply inputting one pulse on the STEP input drives the motor one
step. There are no phase sequence tables, high frequency control lines,
or complex interfaces to program. The A3982 interface is an ideal fit
for applications where a complex microprocessor is unavailable or is
overburdened.
The chopping control in the A3982 automatically selects the current
decay mode (Slow or Mixed). When a signal occurs at the STEP input
pin, the A3982 determines if that step results in a higher or lower
current in each of the motor phases. If the change is to a higher current,
then the decay mode is set to Slow decay. If the change is to a lower
current, then the current decay is set to Mixed (set initially to a fast
decay for a period amounting to 31.25% of the fixed off-time, then
to a slow decay for the remainder of the off-time). This current decay
control scheme results in reduced audible motor noise, increased step
accuracy, and reduced power dissipation.
Internal synchronous rectification control circuitry is provided to
improve power dissipation during PWM operation.
Internal circuit protection includes: thermal shutdown with hysteresis,
undervoltage lockout (UVLO), and crossover-current protection.
Special power-on sequencing is not required.
The A3982 is supplied in a 24-pin wide-body SOIC (package
LB)
with
internally-fused power ground leads. It is also available in a lead (Pb)
free version (suffix
鈥揟),
with 100% matte tin plated leadframes.
Translator
& Control Logic
6
7
8
19 PGND
18 PGND
17 REF
16 STEP
15 VDD
9
VCP 10
VREG 11
MS1 12
Charge
Pump
OSC
Reg
14 ROSC
13 RESET
Approximate Scale 1:1
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage,V
BB
...................................35
V
Output Current, I
OUT
.........................................
鹵2 A
*
Logic Input Voltage, V
IN
.....................
鈥?.3 V to 7 V
Sense Voltage, V
SENSE
.......................................0.5
V
Reference Voltage, V
REF
鈥︹€︹€?.........................4
V
Operating Temperature Range
Ambient, T
A
.................................
鈥?0擄C to 85擄C
Junction Temperature, T
J(MAX)
.....................
150擄C
Storage Temperature, T
S
....................
鈥?5擄C to 150擄C
FEATURES
Low R
DS(ON)
outputs
Automatic current decay mode detection/selection
Mixed and Slow current decay modes
Synchronous rectification for low power dissipation
Internal UVLO and thermal shutdown circuitry
Crossover-current protection
Pb-free
鈥?/div>
Yes
Package
24-pin, Wide SOIC
*
Output current rating may be limited by duty cycle,
ambient temperature, and heat sinking. Under any
set of conditions, do not exceed the specified current
rating or a junction temperature of 150擄C.
Use the following complete part number when ordering:
Part Number
A3982SLB
A3982SLB-T
Ambient
鈥?0擄C to 85擄C
26184.28B
ALLEGRO
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