LB1927

No.6197-6/11

Pin Description

Pin No.

Pin name

Pin function

Equivalent circuit

28

1

2

OUT1

OUT2

OUT3

Motor drive output pins.

Connect a Schottky diode between these outputs and VCC.

3

GND2

Output ground pin.

5

VM

Output block power supply and output current detection pin.

Connect a resistor (Rf) between this pin and VCC to detect the

output current as a voltage.

The output current is limited according to the equation IOUT =

VRF/Rf.

4

VCC

Power supply pin (except for output block).

6

VREG

Regulated power supply output pin (5V output).

Connect a capacitor (approx. 0.1

μF) between this pin and

ground to stabilize the output.

7

PWM

PWM frequency setting pin.

Connect a capacitor between this pin and ground.

C = 3900pF results in a frequency of about 18kHz.

8

CSD

Lock protection circuit operation time setting pin.

Connecting a capacitor of about 10

μF between this pin and

ground results in a protection circuit operation time of about

3.3 seconds.

9

10

XI

XO

Crystal oscillator pins.

Connect to quartz oscillator to generate the reference clock.

When an external clock (of several MHz) is used, the clock

signal should be input via a resistor of about 5.1k

Ω connected

in series with the XI pin. In this case, the XO pin must be left

open.

Continued on next page.