LB11870 Datasheet, PDF (14/14 Pages) Sanyo Semicon Device – Three-Phase Brushless Motor Driver for Polygonal Mirror Motors

LB11870
11. Power Supply Stabilization
Since this IC provides a large output current and adopts a switching drive technique, the power supply line level can
be disrupted easily. Thus capacitors large enough to stabilize the power supply voltage must be inserted between the
VCC pins and ground. The ground leads of these capacitors must be connected to the three pins that are the power
grounds, and they must be connected as close as possible to the pins themselves. If these capacitors (electrolytic
capacitors) cannot be connected close to their corresponding pins, ceramic capacitors of about 0.1 µF must be
connected near these pins.
If reverse torque control mode is selected for use during deceleration, since there are states where power is returned to
the power supply system, the power supply line levels will be particularly easily disrupted. Since the power line level
is most easily disrupted during lock pull-in at high motor speeds, this state needs extra attention; in particular,
capacitors that are adequately large to handle this situation must be selected.
If diodes are inserted in the power supply lines to prevent destruction of the device if the power supply is connected
with reverse polarity, the power supply line levels will be even more easily disrupted, and even larger capacitors must
be used.
12. VREG Stabilization
A capacitor of at least 0.1 µF must be used to stabilize the VREG voltage, which is the control circuit power supply.
The ground lead of that capacitor must be connected as close as possible to the IC control system ground (GND1).
13. Error Amplifier External Component Values
To prevent adverse influence from noise, the error amplifier external components must be located as close to the IC
as possible. In particular, they must be located as far from the motor as possible.
14. FRAME Pin and the IC Metallic Rear Surface
The FRAME pin must be connected to the GND1 and GND2 pins, and the ground side of the electrolytic capacitor
must be connected to GND3. The IC's metallic rear surface is connected to the FRAME pin internally to the IC.
Thermal dissipation can be improved significantly by tightly bonding the metallic surface of the back of the IC
package to the PCB with, for example, a solder with good thermal conductivity.
Specifications of any and all SANYO products described or contained herein stipulate the performance,
characteristics, and functions of the described products in the independent state, and are not guarantees
of the performance, characteristics, and functions of the described products as mounted in the customer’s
products or equipment. To verify symptoms and states that cannot be evaluated in an independent device,
the customer should always evaluate and test devices mounted in the customer’s products or equipment.
SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all
semiconductor products fail with some probability. It is possible that these probabilistic failures could
give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire,
or that could cause damage to other property. When designing equipment, adopt safety measures so
that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective
circuits and error prevention circuits for safe design, redundant design, and structural design.
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herein are controlled under any of applicable local export control laws and regulations, such products must
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above law.
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or otherwise, without the prior written permission of SANYO Electric Co., Ltd.
Any and all information described or contained herein are subject to change without notice due to
product/technology improvement, etc. When designing equipment, refer to the “Delivery Specification”
for the SANYO product that you intend to use.
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not
guaranteed for volume production. SANYO believes information herein is accurate and reliable, but
no guarantees are made or implied regarding its use or any infringements of intellectual property rights
or other rights of third parties.
This catalog provides information as of August, 2002. Specifications and information herein are subject to
change without notice.
PS No. 7256 -14/14