No. 6507-7/17

STK672-080

D1

Rs

L2

VCC1

IOFF

L1

MOSFET

Enable

Divider

Latch circuit

CR

oscillator

Current

divider

Noise

filter

ØA (control signal)

AND

Q

S

R

800kHz

45kHz

Vref

A=1

–

+

ION

A13263

Functional Description

External Excitation Chopper Drive Block Description

Since this hybrid IC adopts an external excitation method, no external oscillator circuit is required.

When a high level is input to øA in the basic driver block circuit shown in the figure and the MOSFET is turned on, the

comparator + input will go low and the comparator output will go low. Since a set signal with the PWM period will be

input, the Q output will go high, and the MOSFET will be turned on as its initial value.

potential and the Vref potential become the same, the comparator output will invert, and the reset signal Q output will

invert to the low level. Then, the MOSFET will be turned off and the energy stored in L1 will be induced in L2 and the

latch circuit set pin occurs.

In this manner, the Q output is turned off and on repeatedly by the reset and set signals, thus implementing constant

current control. The resistor and capacitor on the comparator input are spike removal circuit elements and synchronize

with the PWM frequency. Since this hybrid IC uses a fixed frequency due to the external excitation method and at the

same time also adopts a synchronized PWM technique, it can suppress the noise associated with holding a position when

the motor is locked.

Driver Block Basic Circuit Structure

Input Pin Functions

Pin No.

Symbol

Function

Pin circuit type

11

CLK

Phase switching clock

Built-in pull-up resistor CMOS Schmitt trigger input

10

CWB

Rotation direction setting (CW/CCW)

Built-in pull-up resistor CMOS Schmitt trigger input

15

ENABLE

Output cutoff

Built-in pull-up resistor CMOS Schmitt trigger input

8, 9, 12

M1, M2, M3

Excitation mode setting

Built-in pull-up resistor CMOS Schmitt trigger input

13

RESET

System reset

Built-in pull-up resistor CMOS Schmitt trigger input

7

Vref

Current setting

Input impedance 6 k

Ω (typ.) ±30%