LV8121V

No.A2135-6/14

Pin Function

Pin No.

Pin name

Function

Equivalent circuit

1

PWM

Pin to set the PWM oscillation frequency.

Connect a capacitor between this pin and GND1.

A frequency of about 19kHz can be set by using

a 1800pF capacitor.

VREG

1

950

Ω

200

Ω

2

LIM

Pin to set the minimum output duty.

A minimum output duty can be set by inputting a fixed

voltage to the LIM pin through resistor division of VREG.

Connect the LIM pin to GND1 if this pin is not used, then the

minimum output duty becomes 0 %.

VREG

2

500

Ω

3

CTL

Pin to control the output duty.

The output duty is determined by the result of comparing

the CTL pin voltage with the PWM oscillation waveform.

When the CTL pin is open, the output duty becomes 100%.

Therefore, connect a pull-down resistor to prevent open.

VREG

3

500

Ω

4

S/S

Start / Stop control pin.

Low : 0V to 1.0V

High : 2.0V to VREG

Goes high when left open.

Low for start.

The hysteresis width is about 0.35V.

10k

Ω

VREG

4

100k

Ω

5

6

7

8

9

10

IN3-

IN3+

IN2-

IN2+

IN1-

IN1+

Hall input pins.

The input is seen as the high level input when IN+

> IN-, and

as the low level input for the opposite state.

If noise on the Hall signals is a problem, connect a capacitor

between the corresponding IN+ and IN- inputs.

VREG

8

6

10

7

5

9

Continued on next page.