Motor Driver ICs
Notes on SLA7000/SMA7000 Series
sFeatures
q
Employs a constant-current chopper control method.
q
Integrates power MOSFETs and monolithic chip control cir-
cuitry in a single package.
q
One-fifth the size and one-fourth the power dissipation com-
pared with conventional SANKEN ICs
sConstant
Current Chopper Method
In the constant current chopper method, a voltage higher than
the rated voltage of the motor is applied and when the current
rises, the chopper transistor is switched on thereby shortening
the current rise time. After the current rises, the coil current is
held by the PWM chopper to a constant current level deter-
mined by the current sense resistor. This method has the ad-
vantage of improving the motor's high frequency response and
the efficiency response and efficiency of the driver circuitry.
Comparison of power dissipation.
8
Basic constant current chopper circuitry
Transient-suppression diode
7
Power dissipation P
H
(W)
6
5
4
3
2
1
0
0
10
20
30
40
SLA7024M, SLA7029M
SMA7029M
Sanken product: SI-7300A
Motor coil
Motor : 23LM-C202
I
O
: Output current
2-phase excitation, holding mode
Current sense resistor
I
O
=1A
V
CC
I
O
=1A
50
PWM control
and phase
switching Used as both chopper
control
MOSFET and phase
switching MOSFET
Supply voltage
V
CC
(V)
q
Eliminates the need for heatsink thereby decreasing part-in-
sertion workload and increasing flexibility in mounting.
q
Reduces the size of power supplies required.
q
Lineup: 2-phase excitation, 2-phase/1-2 phase excitation,
2W1-2 phase micro-step support ICs
sApplications
The SLA7000 and SMA7000 series are ideal for the following
applications.
q
Sheet feeders and carriage drivers in printers.
q
Sheet feeders for PPC and facsimile machines.
q
Numeric control equipment.
q
Industrial robots.
sHandling
Precautions
q
Recommended screw torque
0.588 to 0.784 [N•m](6.0 to 8.0 [kgf•cm])
q
Recommended silicon grease
Shin-Etsu Chemical Co., Ltd.: G746
GE Toshiba Silicone Co., Ltd.: YG-6260
Dow Corning Toray Silicone Co., Ltd.: SC102
Please be careful when selecting silicone grease since the oil
in some grease may penetrate the product, which will result
in an extremely short product life.
4
Notes on SLA7000/SMA7000 Series
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