Overview

The LB11921T is a pre-driver IC designed for variable-speed control of 3-phase brushless motors. It can be used to implement a motor drive circuit with the desired output capacity (voltage, current) by using discrete transistors for the output stage. It implements direct PWM drive for minimal power loss. Since the LB11921T includes a built-in VCO circuit, applications can control the motor speed arbitrarily by varying the external clock frequency.

Functions

• Direct PWM drive output

• Speed discriminator + PLL speed control circuit

• Speed lock detection output

• Built-in VCO circuit

• Forward/reverse switching circuit

• Braking circuit (short braking)

• Full complement of on-chip protection circuits, including lock protection, current limiter, and thermal shutdown protection circuits.