lb11693 Sanyo Semiconductor Corporation, lb11693 Datasheet - Page 12

• Manufacturer Part Number: lb11693
• Description: Three-phase Brushless Motor Driver For 24 V Fan Motors
• Manufacturer: Sanyo Semiconductor Corporation

output transistor) on and off repeatedly based on this sawtooth waveform. Motor drive is on during the period the CSD
pin external capacitor is being charged from about 1.0 V to about 3.0 V, and motor drive is off during the period the
CSD pin external capacitor is being discharged from about 3.0 V to about 1.0 V. The IC and the motor are protected by
this repeated drive on/off operation when the motor is physically constrained. When a 0.47 µF capacitor is connected to
the CSD pin, this repeated operation will turn motor drive on for about 0.4 seconds and off for about 5.5 seconds.
When the motor is turning, the CSD pin is held at a certain fixed voltage (which varies depending on the motor speed)
by the CSD pin external capacitor being charged and discharged by two processes. One is the constant current (about
2.4 µA) charge current, and the other is a roughly 10 µs discharge pulse generated internal in the IC when the Hall
sensor input IN1 changes state (on rising and falling edges on the FG output).
Since the Hall sensor input IN1 does not change state when the motor is not turning, discharge pulses are not generated,
and the CSD pin external capacitor is charged by the approximately 2.4 µA constant current until it reaches about 3.0 V.
At that point, the constraint protection circuit operates. The constraint protection state is cleared if the motor constraint
is released.
When the motor turns at an extremely low rate, the CSD pin voltage during this motor rotation will be held at a
relatively high voltage, and the constraint protection circuit will operate if this reaches the roughly 3.0 V threshold
level. Since the constraint protection circuit may operate if the Hall sensor input IN1 frequency falls below about 10 Hz,
care is required when using the constraint protection circuit with a motor that turns slowly.
Connect the CSD pin to ground if the constraint protection circuit is not used.
This catalog provides information as of November, 2004. Specifications and information herein are
subject to change without notice.
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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contained herein are controlled under any of applicable local export control laws and regulations,
such products must not be expor ted without obtaining the expor t license from the author ities
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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
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LB11693
PS No.8095-12/12