Overview
The LB1860 series ICs are drivers for two-phase unipolar drive DC brushless fan motors. They have functions such as driving, lock protection, restart and speed control.

Features and Functions
• Two-speed mode select function requiring less external component additions: Full speed and Low speed. Or, thermistor-controlled continuous variable-speed function according to ambient operation temperatures.
    → Motor starts rotating at a low speed.
• Motor lock protection and automatic return circuit built in
• Output transistors: Output current IO = 1.5 A, output circuit protection Zener diodes (LB1860: M-Vz = 57 V/ LB1861: M-Vz = 32 V)
    → Enables low-level noise protection with chip capacitor.
• Built-in thermal shutdown circuit
• Built-in rotation detect function (Drive mode: ‘‘L’’, Stop mode: ‘‘H’’)
• The LB1860 series can be operated from either 12 V or 24 V power supply by changing an external resistor. (Strong protection against power supply surge)
• Connectable direct to a Hall element