ALLEGRO SLA7042

MICROSTEPPING, UNIPOLAR PWM,
HIGH-CURRENT MOTOR CONTROLLER/DRIVER
2
VREF
4
VCC
7
8
9
SENSE B
10
OUT B
11
GROUND B
12
14
15
18
ø
17
D/A
16
OUT B
SR/LATCH
CLOCK B
SERIAL DATA B
CONTROL/LOGIC
13
CNTRL SPLY B
VREF VCC
STROBE B
REF/ENABLE B
+
6
OUT A
SENSE A
+
5
GROUND A
D/A
3
CLOCK A
SERIAL DATA A
ø CONTROL/LOGIC
1
REF/ENABLE A
CNTRL SPLY A
SR/LATCH
OUT A
STROBE A
The SLA7042M and SLA7044M are designed for high-efficiency
and high-performance microstepping operation of 2-phase, unipolar
stepper motors. Microstepping provides improved resolution without
limiting step rates, and provides much smoother low-speed motor
operation. An automated, innovative packaging technology combined
with power NMOS FETs and monolithic CMOS logic/control circuitry
advances power multi-chip modules (PMCMs™) toward the complete
integration of motion control. Each half of these stepper motor controller/drivers operate independently. The 4-bit shift registers are serially
loaded with motor phase information and output current-ratio data (eight
levels). The combination of user-selectable current-sensing resistor,
linearly adjustable reference voltage, and digitally selected output
current ratio provides users with a broad, variable range of of full, half,
and microstepping motor control (IOUT ≈ [VREF/3 • RS] • Current Ratio).
Dwg. PK-008
ABSOLUTE MAXIMUM RATINGS
at TA = +25°C
Load Supply Voltage, VBB . . . . . . . . . . . . 46 V
FET Output Voltage, VDS . . . . . . . . . . . 100 V
Control Supply Voltage, VDD . . . . . . . . . 7.0 V
Peak Output Current,
IOUTM (tw ≤ 10 µs) . . . . . . . . . . . . . . . . 5.0 A
Continuous Output Current, IOUT
SLA7042M . . . . . . . . . . . . . . . . . . . . . 1.5 A
SLA7044M . . . . . . . . . . . . . . . . . . . . . 3.0 A
Input Voltage Range,
VIN . . . . . . . . . . . . . . -0.3 V to VDD + 0.3 V
Reference Voltage, VREF . . . . . . . . . . . . VDD
Package Power Dissipation, PD . See Graph
Junction Temperature, TJ . . . . . . . . . +150°C
Each PMCM is rated for a maximum motor supply voltage of 46 V
and utilizes advanced NMOS FETs for the high-current, high-voltage
driver outputs. The avalanche-rated (≥100 V) FETs provide excellent
ON resistance, improved body diodes, and very-fast switching. The
multi-chip ratings and performance afford significant benefits and
advantages for stepper drives when compared to the higher dissipation
and slower switching speeds associated with bipolar transistors. Highly
automated manufacturing techniques provide low-cost and exceptionally reliable PMCMs suitable for controlling and directly driving a broad
range of 2-phase, unipolar stepper motors. The SLA7042M and
SLA7044M are identical except for rDS(on) and output current ratings.
Complete applications information is given on the following pages.
PWM current is regulated by appropriately choosing current-sensing
resistors, a voltage reference, and digitally programmable current ratio.
Inputs are compatible with 5 V logic and microprocessors.
BENEFITS AND FEATURES
■
■
■
■
■
■
■
■
■
Operating Temperature Range,
TA . . . . . . . . . . . . . . . . . . . . -20°C to +85°C
Storage Temperature Range,
Tstg . . . . . . . . . . . . . . . . . . -40°C to +150°C
Cost-Effective, Multi-Chip Solution
‘Turn-Key’ Motion-Control Module
Motor Operation to 3 A and 46 V
3rd Generation High-Voltage FETs
100 V, Avalanche-Rated NMOS
Low r DS(on) NMOS Outputs
Advanced, Improved Body Diodes
Microstepping Unipolar Drive
High-Efficiency, High-Speed PWM
■ Independent PWM Current Control
(2-Phase)
■ Digitally Programmable PWM
Current Control
■ Low Component-Count PWM Drive
■ Low Internal-Power Dissipation
■ Electrically Isolated Power Tab
■ Logic IC- and µP-Compatible
Inputs
■ Machine-Insertable Package
Always order by complete part number: SLA7042M .
™
Data Sheet
28202A*
SLA7042M AND
SLA7044M
SLA7042M AND SLA7044M
MICROSTEPPING,
UNIPOLAR PWM, HIGH-CURRENT
MOTOR CONTROLLER/DRIVERS
FUNCTIONAL BLOCK DIAGRAM
CONTROL
SUPPLY
OUT A/B
4
1
8
15
11
18
OUT A/B
VDD
REF/ENABLE
3
14
ENABLE
+
V
STROBE
2
13
D/A
REF
+
PROGRAMMABLE
PWM OFF TIMER
NOISE FILTER
V DD – 1
LATCHES
PHASE
DATA
6
17
CLOCK
5
16
SHIFT REG
12
10
7
9
GROUND
SENSE
CHANNEL A PIN NUMBERS
CHANNEL B PIN NUMBERS
Note that channels A and B are electrically isolated.
ALLOWABLE PACKAGE
POWER DISSIPATION
ALLOWABLE PACKAGE POWER DISSIPATION in WATTS
Dwg. FK-006
25
20
R θJM = 5.0°C/W
15
10
5
R θJA = 28°C/W
0
25
50
75
100
TEMPERATURE in °C
125
150
Dwg. GK-018-1
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1995, 1998 Allegro MicroSystems, Inc.
™
SLA7042M AND SLA7044M
MICROSTEPPING,
UNIPOLAR PWM, HIGH-CURRENT
MOTOR CONTROLLER/DRIVERS
DC ELECTRICAL CHARACTERISTICS at TA = +25°C, VDD = 5 V unless otherwise noted.
Limits
Characteristic
FET Leakage Current
FET ON Voltage
FET ON Resistance
Body Diode Forward Voltage
Control Supply Voltage
Control Supply Current
Logic Input Voltage
Logic Input Current
REF/ENABLE Input Voltage
Symbol
IDSS
Test Conditions
Min
Typ
Max
Units
VDS = 100 V
—
—
4.0
mA
SLA7042M, IOUT = 1.2 A
—
—
800
mV
SLA7044M, IOUT = 3 A
—
—
855
mV
SLA7042M, IOUT = 1.2 A
—
—
0.67
Ω
SLA7044M, IOUT = 3 A
—
—
0.285
Ω
SLA7042M, IOUT = –1.2 A
—
—
1.2
V
SLA7044M, IOUT = –3 A
—
—
1.6
V
VDD
Operating
4.5
5.0
5.5
V
IDD
Each controller, VDD = 5.5 V
VDS(ON)
rDS(on)
VSD
—
—
7.0
mA
VIN(1)
3.5
—
—
V
VIN(0)
—
—
1.5
V
IIN(1)
VIN(1) = VDD
—
—
1.0
µA
IIN(0)
VIN(0) = 0
—
—
–1.0
µA
DATA, CLOCK, STROBE, and OUT Enabled
0.4
—
2.5
V
DATA, CLOCK, STROBE, and OUT Disabled
VDD - 1
—
—
V
VREF/EN
REF/ENABLE Input Current
IREF/EN
0 V ≤ VREF/EN ≤ 5 V
—
—
±1.0
µA
Step Reference
SRCR
DATA Input = 000X
—
0
—
%
DATA Input = 001X
—
20
—
%
DATA Input = 010X
—
40
—
%
DATA Input = 011X
—
55.5
—
%
First Bit Entered (X) = Phase
DATA Input = 100X
—
71.4
—
%
Second Bit Entered = LSB
DATA Input = 101X
—
83
—
%
Last Bit Entered = MSB
DATA Input = 110X
—
91
—
%
DATA Input = 111X
—
100
—
%
Current Ratio
NOTE: Negative current is defined as coming out of (sourcing) the specified device pin.
TYPICAL AC CHARACTERISTICS at TA = +25°C, VDD = 5 V, IOUT = 1 A, Logic Levels are VDD and
Ground
PWM OFF Time
Output RiseTime
tr
Output Fall Time
tf
Strobe-to-Output Switching Time tpd
DATA Input = 001X ................................................................. 7 µs
DATA Input = 010X ................................................................. 7 µs
DATA Input = 011X ................................................................. 9 µs
DATA Input = 100X ................................................................. 9 µs
DATA Input = 101X ................................................................. 9 µs
DATA Input = 110X ................................................................ 11 µs
DATA Input = 101X ................................................................ 11 µs
10% to 90% ........................................................................... 0.5 µs
90% to 10% ........................................................................... 0.1 µs
50% to 50% ........................................................................... 0.7 µs
SLA7042M AND SLA7044M
MICROSTEPPING,
UNIPOLAR PWM, HIGH-CURRENT
MOTOR CONTROLLER/DRIVERS
D
D
CLOCK
B
A
E
A
DATA
B
C
C
STROBE
F
Dwg. WK-002
SERIAL PORT TIMING CONDITIONS
(TA = +25°C, Logic Levels are VDD and Ground)
A.
B.
C.
D.
E.
F.
Minimum Data Active Time Before Clock Falling Edge (Data Set-Up Time) ...........
Minimum Data Active Time After Clock Falling Edge (Data Hold Time) ..................
Minimum Data Pulse Width ......................................................................................
Minimum Clock Pulse Width ....................................................................................
Minimum Time Between Clock and Strobe Falling Edges .......................................
Minimum Strobe Pulse Width ...................................................................................
150 ns
150 ns
350 ns
350 ns
650 ns
500 ns
APPLICATIONS INFORMATION
The SLA7042M and SLA7044M modules integrate two
CMOS controller ICs and four NMOS FETs. Each half of the
device operates independently, although the CLOCK inputs
may be connected together and the STROBE inputs may be
connected together. Pulling VREF/EN low (<2.5 V) allows the 4bit shift registers to be serially loaded with motor phase and
output currrent ratioing data.
The first bit selects the motor phase (logic high = Output A
or B, logic low = Output A or B); the next three bits determine
the motor current ratio (eight steps, 0% to 100%). The internal
D/A converter, in conjunction with a current-sensing resistor
and input reference voltage, completes the microstepping
current control.
Pulling VREF/EN high (within 1 V of VDD) resets the shift
register and latches to turn the MOS drivers OFF and inhibits
the serial DATA input.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
™
SLA7042M AND SLA7044M
MICROSTEPPING,
UNIPOLAR PWM, HIGH-CURRENT
MOTOR CONTROLLER/DRIVERS
REGULATING THE PWM OUTPUT CURRENT
SERIAL DATA INPUT ENABLE
The output current (and motor coil current) waveform
is illustrated in Figure 1. Setting the maximum PWM
current trip point to meet the specified full-step running
current for the motor, IOUT max (DATA input = 111X =
100% ratio), requires only a current-sensing resistor, RS,
and an input reference voltage, VREF/EN , between 0.4 V
and 2.5 V.
In a minimum-component application, a voltage divider
provides VREF/EN and an npn transistor provides the
required pull-down to enable the serial data input as
shown in Figure 2.
IOUT max ≈
IOUT max ≈
R2
R1 + R2
Vb
•
3 • RS
VREF/EN
3 • RS
µP STEPPER MOTOR CONTROL
I OUT
PHASE A
0
PHASE A
Alternative REFERENCE/ENABLE input configurations provide for more complete motor control. A tri-state
logic element and a voltage divider allows a fixed reference voltage, with both output disable and data enable
functions. Complete µP control is usually accomplished
with a D/A converter as shown in Figure 3. Here, digital
control provides an output disable (>VDD - 1 V), VREF, and
VEN (<2.5 V).
Dwg. WK-001
FIGURE 1.␣ PHASE A COIL CURRENT WAVEFORM
VDD
SERIAL DATA
V BB
B
Vb
TO CHANNEL B
B
R1
Ø
VREF/EN
ENABLE
DATA
D/A
PWM
OFF-TIME
CONTROL
A
A
CONTROL
LOGIC
DRIVE
R2
SENSE
RS
Dwg. EK-011
FIGURE 2.␣ PWM CONTROL (RUN MODE)
SLA7042M AND SLA7044M
MICROSTEPPING,
UNIPOLAR PWM, HIGH-CURRENT
MOTOR CONTROLLER/DRIVERS
Vb
V DD
TO OTHER CHANNEL
(OPTIONAL)
R1
D/A
V
REF/EN
......
R2
FROM µP
111...1 = OFF
000...0 = ENABLE DATA
H = OFF
Z = REFERENCE
L = ENABLE DATA
Dwg. EK-012
FIGURE 3. ␣COMPLETE CONTROL
SERIAL DATA INPUT
motor phase — a high level enables OUTA or OUTB, a low
level enables OUTA or OUT B. The next three bits set the
step reference voltage ratio and PWM OFF time as shown
in the Characteristics Tables — the least-significant bit first
and the most-significant bit last.
The serial DATA input port is enabled (active low) by
the REFERENCE/ENABLE input. When VREF/EN is between 0.4 V and 2.5 V, information on the DATA input is
read into the shift register on each high-to-low transition of
the CLOCK.
Data written into the serial data port is latched and
becomes active on a high-to-low transition at STROBE.
There are four bits: the first bit entered controls the
LOAD CURRENT
(NOT TO SCALE)
DISABLED
0
VDD
VDD - 1 V
MOTOR PWM OPERATION
2.5 V
ENTER
DATA
REFERENCE/ENABLE
0
3.1 µs
MIN
VDD
CLOCK
0
VDD
SERIAL DATA
0
DON'T CARE
0
0 1 0
= 20%
0
DATA LATCHED
1 0 0
= 40%
VDD
STROBE
0
Dwg. WK-003
FIGURE 4. ␣TIMING RELATIONSHIPS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
™
SLA7042M AND SLA7044M
MICROSTEPPING,
UNIPOLAR PWM, HIGH-CURRENT
MOTOR CONTROLLER/DRIVERS
REFERENCE/ENABLE INPUT
TEMPERATURE EFFECTS ON FET rDS(on)
The serial DATA input port is enabled (active low) by
the REFERENCE/ENABLE input when VREF/EN is between
0.4 V and 2.5 V. With VREF/EN greater than V DD - 1 V, the
serial DATA input port is disabled, the outputs are OFF,
and the controller/driver will not be affected by changes at
the DATA, CLOCK, or STROBE inputs.
Analyzing safe, reliable operation includes a concern
for the relationship of NMOS ON resistance to junction
temperature. Device package power calculations must
include the increase in ON resistance (producing higher
output ON voltages) caused by higher operating junction
temperatures. Figure 5 provides a normalized ON resistance curve, and all thermal calculations should consider
increases from the given +25°C limits, which may be
caused by internal heating during normal operation.
In a typical (SLA7042M) application where VDD = 5 V,
a VREF/EN between 0.4 V and 2.5 V, and a maximum
allowable load current of 1.2 A, the maximum value of RS
is 0.69 Ω and IOUTmin is 0.11 A when SRCR is 100%
(DATA input = 111X).
POWER DISSIPATION CALCULATIONS
The SLA7042/44M normally do not require special
heat sinking except under unusual circumstances (two
phases operating near maximum output current and TA
>65°C). However, as with all power drivers, the basic
constituents of power dissipation should be evaluated.
Conduction losses (internal power dissipation) include:
(a) FET output power dissipation (IOUT2 • rDS(on) or
IOUT • VDS(ON)),
(b) FET body diode power dissipation (VSD • IOUT), and
(c) control circuit power dissipation (VDD • IDD ).
PACKAGE RATINGS/DERATING FACTORS
Thermal calculations must also consider the temperature effects on the output FET ON resistance. The applicable thermal ratings for the 18-lead power-tab SIP PMCM
package are:
RθJA = 28°C/W (junction to ambient with no heat sink)
or 4.5 W at +25°C and a derating factor of -36 mW/°C
for operation above +25°C.
RθJM = 5°C/W (junction to mounting surface).
2.5
NORMALIZED FET ON RESISTANCE
With VREF/EN between 0.4 V and 2.5 V, the output
current limit is a linear function of VREF and the step
reference current ratio.
VREF
IOUT ≈
• SRCR
3 • RS
2.0
1.5
1.0
0.5
0
-40
0
+40
+80
JUNCTION TEMPERATURE in °C
+120
+160
Dwg. GK-017
FIGURE 5.␣ NORMALIZED ON RESISTANCE
vs TEMPERATURE
The power MOSFET outputs of these devices are
similar to the International Rectifier type IRL510
(SLA7042M) and IRL520 (SLA7044M). These devices
feature an excellent combination of fast switching, ruggedized device design, low on-resistance, and cost effectiveness.
SLA7042M AND SLA7044M
MICROSTEPPING,
UNIPOLAR PWM, HIGH-CURRENT
MOTOR CONTROLLER/DRIVERS
Dimensions in Inches
(for reference only)
0.126 ±0.006 x 0.150
1.22 ±0.008
0.126
±0.006
0.961 ±0.008
ø
0.189
±0.008
0.646
0.067
0.512
±0.008
0.390
±0.008
0.630
±0.004
±0.008
±0.008
0.096
±0.008
0.264
±0.020
0.118
1
18
1.232 ±0.008
+0.008
0.026 –0.004
+0.008
0.022
–0.004
0.157
0.066
±0.028
±0.016
Dwg. MK-002-18 in
Dimensions in Millimeters
(controlling dimensions)
3.2 ±0.15 x 3.8
31±0.2
3.2
±0.15
24.4 ±0.2
ø
4.8
±0.2
16.4 ±0.2
1.7
13 ±0.2
9.9 ±0.2
16 ±0.2
±0.1
2.45
±0.2
6.7
±0.5
3.0
1
18
0.55 +0.2
–0.1
31.3 ±0.2
+0.2
0.65 –0.1
1.68
±0.4
4.0
±0.7
Dwg. MK-002-18 mm
The products described here are manufactured in Japan by Sanken Electric Co.,
Ltd. for sale by Allegro MicroSystems, Inc.
Sanken Electric Co., Ltd. and Allegro MicroSystems, Inc. reserve the right to
make, from time to time, such departures from the detail specifications as may be
required to permit improvements in the design of their products.
The information included herein is believed to be accurate and reliable.
However, Sanken Electric Co., Ltd. and Allegro MicroSystems, Inc. assume no
responsibility for its use; nor for any infringements of patents or other rights of third
parties which may result from its use.
NOTES: 1. Exact body and lead configuration at vendor’s option within
limits shown.
2. Recommended mounting hardware torque: 4.34 – 5.79 lbf•ft (6 – 8
kgf•cm or 0.588 – 0.784 Nm).
3. The shaded area is exposed (electrically isolated) heat spreader.
4. Recommend use of metal-oxide-filled, alkyl-degenerated oil base,
silicone grease (Dow Corning 340 or equivalent).
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
™