STK672-401C-E

No.A2137-6/19

[Setting the motor current]

The motor current is set by the hybrid IC's pin 19V, Vref. The formula shows below gives the relationship between IOH

and Vref.

Vref = VDD-(IOH × Rs × K) ···························································································································· (1)

K: 9.33 (voltage divider ratio)

Rs: 0.152

Ω (hybrid IC internal current detection resistance: precision = ±3%)

Model of the Motor Phase Current Flowing into the Hybrid IC

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

CLK rising edge

0

1-2 phase

excitation

W1-2 phase

excitation

2W1-2 phase

excitation

4W1-2 phase

excitation

Both CLK edges

CWB pin

ENABLE and RESET pins

Forward

Reverse

ENABLE

Motor current cut: Low

CWB

0

1

RESET

Active Low

0A

IOH

IOL

Ioave