STK672-080-E

No.6507-6/18

Power-on Reset

The application must perform a power-on reset operation when VCC2 power is first applied to this hybrid IC.

Application circuit that used 2W1-2 phase excitation (microstepping operation) mode.

Setting the Motor Current

The motor current IOH is set by the Vref voltage on the hybrid IC pin 7. The following formula gives the relationship

between IOH and Vref.

RoX = (Ro2

× 6kΩ) ÷ (Ro2 + 6kΩ)

(1)

Vref = VCC2 × RoX ÷ (Ro1 + RoX)

(2)

IOH =

×

(3)

K: 4.7 (Voltage divider ratio),

Rs: 0.15

Ω (This is the hybrid IC's internal current detection resistor. It has a tolerance of ±3%.)

Applications can use motor currents from the current (0.05 to 0.1A) set by the duty of the frequency set by the oscillator

up to the limit of the allowable operating range, IOH = 2.8A

Function Table

M2

0

0

1

1

M1

M3

0

1

0

1

Phase switching clock edge timing

1

2 phase excitation

1-2 phase excitation

W1-2 phase excitation

2W1-2 phase excitation

Rising edge only

0

1-2 phase excitation

W1-2 phase excitation

2W1-2 phase excitation

4W1-2 phase excitation

Rising and falling edges

Forward

Reverse

ENABLE

Motor current is cut off when low

CWB

0

1

RESET

Active low

K

1

Rs

Vref

7

5

A

AB

6

14

14

8

14

14

9

14

14

12

15

11

13

10

14

+

+

VCC2=5V

VCC2=5V

SG

PG

Vref

Ro1

Ro2

VCC2=5V

CLK

ENABLE

CBW

RESET

MOI

VCC1=10V to 45V

Two-phase stepping motor

STK672-080-E

A13261

B

BB

RoX

4

3

2

1

VF 0.3V

Simple power on reset circuit

(This circuit cannot be used for

power supply voltage drop

detection.)

We recommend a value of about

100

Ω for Ro2 to minimize the

influence of the Vref pin internal

impedance, which is 6k

Ω

RoX: Input impedance: 6k

Ω±30%

Motor current waveform

Ioave

IOL IOH

0A

A13262