STK672-340-E

No.A1254-4/13

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. Also, if at all possible, the ground used for Vref must not be common to the P.GND pattern, but

must be directly wired from pin 1.

• 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.

• Apply 2.5V High level input to pins 8, 9, 10, 11, and 12.

• Since the input pins do not have built-in pull-up resistors, when the open-collector type pins 8, 9, 10, 11, and 12 are

used as inputs, a 10 to 47k

Ω pull-up resistor (to VDD) must be used.

• To prevent incorrect operation due to chopping noise, we recommend inserting 470 to 1000pF capacitors between pin

1 and each of the pins 8, 9, 10, and 12.

(With the open-collector type IC, we also recommend inserting a 470 to 1000pF capacitor between pin 11 (RESETB)

and pin 1 when pin 11 is used as an input.)

• 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

ITF02172

ITF02171

VDD=5V

CLOCK

MODE

CWB

5V

5V

RESETB

6

9

8

10

11

7

ENABLE

12

D1

RO3

RO4

20k

Ω

CO4

10

μF

RO1

Vref

RO2

0.1

μF

CO1

CO3

+

+

+

10

μF

5

A

4

AB

3

B

2

BB

1

GND

STK672-340-E

CO2

At least 100

μF

VCC

24V

P.GND

ITF02170

2-phase stepping motor