STK672-110-E

No.6041-4/9

Sample Application Circuit

• To minimize noise in the 5V system, locate the ground side of capacitor CO2 in the above circuit as close as possible

to pin 1 of the IC.

• Insert resistor RO3 (47 to 100Ω) so that the discharge energy from capacitor CO4 is not directly applied to the CMOS

IC in this hybrid device. If the diode D1 has Vf characteristics with Vf less than or equal to 0.6V (when If = 0.1A),

this will be smaller than the CMOS IC input pin diode Vf. If this is the case RO3 may be replaced with a short

without problem.

• Standard or HC type input levels are used for the pin 7, 8, and 9 inputs.

• If open-collector type circuits are used for the pin 7, 8, and 9 inputs, these circuit will be in the high-impedance state

for high level inputs. As a result, chopping circuit noise may cause the input circuits to operate incorrectly. To prevent

incorrect operation due to such noise, capacitors with values between 470 and 1000pF must be connected between

pins 7 and 11, 8 and 11, and 9 and 11. (A capacitor with a value between 470 and 1000pF must be connected between

pins 6 and 11 as well if an open-collector output IC is used for the RESETB pin (pin 6) input.)

• Taking the input bias current (IIB) characteristics into account, the resistor RO1 must not exceed 100kΩ.

• The following circuit (for a lowered current of over 0.2A) is recommended if the application needs to temporarily

lower the motor current. Here, a value of close to 100k

Ω must be used for resistor RO1 to make the transistor output

saturation voltage as low as possible.

5V

RO1

RO2

RO3

Vref

5V

RO1

RO2

RO3

Vref

STK672-110-E

CO3

10

μF

RESETB

5V

RO1

RO2

0.1

μF

CO1

Vref

RO3

5V

D1

CO4

+

+

+

10

μF

9

10

8

7

6

12

1

ITF02597

P.GND

VCC

24V

2

3

4

5

A

AB

B

BB

GND

CO2

At least 100

μF

Two-phase stepping motor

VDD=5V

CLOCK

MODE

CWB

11