LB11850VA-TLM-H Datasheet, PDF (1/14 Pages) ON Semiconductor – For Fan Motor Single-Phase Full-Wave Pre-Driver with Speed Control Function

Ordering number : ENA0609A
LB11850VA
Monolithic Digital IC
For Fan Motor
Single-Phase Full-Wave Pre-Driver
with Speed Control Function
http://onsemi.com
Overview
The LB11850VA 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 system.
• 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
Semiconductor Components Industries, LLC, 2013
May, 2013
32207 MS IM 20070301-S00003 / D0606 MH IM 20060619-S00002 No.A0609-1/15