Pin No.

Pin

Pin voltage (V)

Pin description

Equivalent circuit

No. 5798-3/5

LB1855NM

Sample Application Circuit

70 mV p-p to 300 mV p-p AC

Truth Table

Input: “H” indicates that the input phase 1 is at least 0.2 V higher than phase 2.

“L” indicates that the input phase 1 is at least 0.2 V lower than phase 2.

1

FC

• Frequency characteristics correction

Oscillation in the current control closed loop can be prevented

by inserting a capacitor between this pin and VREF.

Item

Source

→ sink

Input

U

V

W

1

V phase

→ W phase

H

H

L

2

U phase

→ W phase

H

L

L

3

W phase

→ V phase

L

L

H

4

V phase

→ U phase

L

H

L

5

U phase

→ V phase

H

L

H

6

W phase

→ U phase

L

H

H

Pin Functions

2

7 to 18

• Power supply pin

3

4

5

• Outputs pin

6

• Ground for the output transistor

The output current can be detected as a voltage by inserting the

resistor Rf between this pin and ground to provide fixed current

drive. The current limiter also operates by detecting this voltage.

Continued on next page.

However, note that certain motors may require output capacitors to prevent oscillation.