ALLEGRO A3982 User Manual
查询A3982供应商查询A3982供应商
A3982
DMOS Stepper Motor Driver with Translator
OUT2A
SENSE2
VBB2
OUT2B
ENABLE
PGND
PGND
CP1
CP2
VCP
VREG
MS1
Package LB
1
2
3
4
5
6
7
Charge
Reg
Translator
Pump
8
9
10
11
12
Approximate Scale 1:1
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
OUT1A
24
SENSE1
23
VBB1
22
OUT1B
21
DIR
20
PGND
19
PGND
18
REF
OSC
17
16
15
14
13
STEP
VDD
ROSC
RESET
& Control Logic
and ±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.
AB SO LUTE MAX I MUM RAT INGS
Load Supply Voltage,V
Output Current, I
OUT
Logic Input Voltage, V
Sense Voltage, V
SENSE
Reference Voltage, V
Operating Temperature Range
Ambient, T
................................. –20°C to 85°C
A
Junction Temperature, T
Storage Temperature, T
*
Output current rating may be limited by duty cycle,
...................................35 V
BB
......................................... ±2 A
..................... –0.3 V to 7 V
IN
.......................................0.5 V
………..........................4 V
REF
.....................150°C
J(MAX)
.................... –55°C to 150°C
S
ambient temperature, and heat sinking. Under any
set of conditions, do not exceed the specified current
rating or a junction temperature of 150°C.
26184.28B
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 –T), with 100% matte tin plated leadframes.
FEATURES
Low R
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
Use the following complete part number when ordering:
Part Number Pb-free Package Ambient
A3982SLB –
A3982SLB-T Yes
DS(ON)
outputs
24-pin, Wide SOIC –20°C to 85°C
DMOS Stepper Motor Driver with Translator
Functional Block Diagram
0.22 μF
A3982
0.1 μF
VDD
REF
STEP
DIR
RESET
MS1
ENABLE
DAC
Translator
VREG
Current
Regulator
PWM Latch
Blanking
Mixed Decay
Control
Logic
PWM Latch
Blanking
Mixed Decay
OSC
ROSC
Gate
Drive
DMOS Full Bridge
DMOS Full Bridge
CP1
Charge
Pump
CP2
VCP
VBB1
OUT1A
OUT1B
SENSE1
VBB2
OUT2A
OUT2B
SENSE2
0.1 μF
R
S1
R
S2
26184.28B
DAC
V
REF
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
2
A3982
DMOS Stepper Motor Driver with Translator
ELECTRICAL CHARACTERISTICS1 at T
Characteristics Symbol Test Conditions Min.
= 25°C, V
A
= 35 V (unless otherwise noted)
BB
Typ.
2
Max. Units
Output Drivers
Load Supply Voltage Range V
Logic Supply Voltage Range V
Output On Resistance R
Body Diode Forward Voltage V
Motor Supply Current I
Logic Supply Current I
BB
DD
DSON
F
BB
DD
Operating 8 – 35 V
Operating 3.0 – 5.5 V
Source Driver, I
Sink Driver, I
= –1.5 A – 0.370 0.460 Ω
OUT
= 1.5 A – 0.330 0.380 Ω
OUT
Source Diode, IF = –1.5 A – – 1.2 V
Sink Diode, I
f
< 50 kHz – – 4 mA
PWM
= 1.5 A – – 1.2 V
F
Operating, outputs disabled – – 2 mA
f
< 50 kHz – – 8 mA
PWM
Outputs off – – 5 mA
Control Logic
Logic Input Voltage
Logic Input Current
Input Hysteresis V
Blank Time
t
Fixed Off-Time
Reference Input Voltage Range V
Reference Input Current I
Current Trip-Level Error
3
Crossover Dead Time t
V
IN(1)
V
IN(0)
I
IN(1)
I
IN(0)
HYS(IN)
BLANK
t
OFF
REF
REF
err
I
DT
V
×0.7
DD
––
VIN = V
V
= V
IN
DD
DD
×0.7
×0.3
–20 <1.0 20 μA
–20 <1.0 20 μA
150 300 500 mV
0.7 1 1.3 μs
OSC > 3 V 20 30 40 μs
R
= 25 kΩ 23 30 37 μs
OSC
0–4V
–3 0 3 μA
V
REF
V
REF
= 2 V, %I
= 2 V, %I
= 70.71% – – ±5 %
TripMAX
= 100.00% – – ±5 %
TripMAX
100 475 800 ns
––V
V
×0.3
DD
V
Protection
Thermal Shutdown Temperature T
Thermal Shutdown Hysteresis T
UVLO Enable Threshold UV
UVLO Hysteresis UV
1
Negative current is defined as coming out of (sourcing from) the specified device pin.
2
Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions. Performance may vary for
individual units, within the specified maximum and minimum limits.
3
errI = (I
Trip – IProg
) ⁄ I
Prog
, where I
Prog
= %I
TripMAX
J
JHYS
LO
HYS
×
VDD rising 2.35 2.7 3 V
I
.
TripMAX
– 165 – °C
–15–°C
0.05 0.10 – V
26184.28B
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
3
Loading...