Ordering number : ENA0608A
Monolithic Digital IC
For Fan Motor
Single-Phase Full-Wave Pre-Driver
with Speed Control Function
The LB11850V is a single-phase bipolar fan motor driver with speed control function that works with a speed feedback
signal. A highly efficient, quiet and low power consumption motor driver circuit, with a high speed accuracy and large
variable speed can be implemented by adding a small number of external components.
This pre-driver is optimal for driving large scale fan motors (with large air volume and large current) such as those used
in servers and consumer products.
Functions and features
• Pre-driver for single-phase full-wave drive
→PMOS-NMOS is used as an external power TR, enabling high-efficiency and low-power-consumption drive by
means of the low-saturation output and single-phase full-wave drive.
• On-chip speed control circuit
→The speed control (closed loop control) using a speed feedback signal makes it possible to achieve higher speed
accuracy and lower speed fluctuations when supply voltage fluctuates or load fluctuates, compared with an open-
loop control system. Separately excited upper direct PWM control method is used as the variable-speed control
• External PWM input or analog voltage input enabling variable speed control
→The speed control input signal is compatible with PWM duty ratio or analog voltages.
• On-chip soft start circuit
• Lowest speed setting pin
→The lowest speed can be set with the external resistor.
• Current limiter circuit incorporated
→Chopper type current limit at start or lock.
• Reactive current cut circuit incorporated
→Reactive current before phase change is cut to enable silent and low-consumption drive.
• Constraint protection and automatic reset functions incorporated
• FG (speed detection), RD (lock detection) output
• Constant-voltage output pin for hall bias
Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to
"standard application", intended for the use as general electronics equipment (home appliances, AV equipment,
communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be
intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace
instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety
equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case
of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee
thereof. If you should intend to use our products for applications outside the standard applications of our
customer who is considering such use and/or outside the scope of our intended standard applications, please
consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our
customer shall be solely responsible for the use.
Specifications of any and all SANYO Semiconductor Co.,Ltd. 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
32207 MS IM 20070301-S00002 / D0606 MH IM 20060619-S00001 No.A0608-1/14