stk672-080-e Sanyo Semiconductor Corporation, stk672-080-e Datasheet - Page 6

• Manufacturer Part Number: stk672-080-e
• Description: Unipolar Constant-current Chopper External Excitation Pwm Circuit With Built-in Microstepping Controller Stepping Motor Driver Sine Wave Drive Output Current 2.8a No Heat Sink*
• Manufacturer: Sanyo Semiconductor Corporation

Power-on Reset
The application must perform a power-on reset operation when V CC 2 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 I OH is set by the Vref voltage on the hybrid IC pin 7. The following formula gives the relationship
between I OH and Vref.
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, I OH = 2.8A
Function Table
M3
CWB
1
0
RoX = (Ro2 × 6kΩ) ÷ (Ro2 + 6kΩ)
Vref = V CC 2 × RoX ÷ (Ro1 + RoX)
I OH =
K: 4.7 (Voltage divider ratio),
Rs: 0.15Ω (This is the hybrid IC's internal current detection resistor. It has a tolerance of ±3%.)
M2
M1
Simple power on reset circuit
(This circuit cannot be used for
power supply voltage drop
detection.)
V F 0.3V
1-2 phase excitation
2 phase excitation
K
1
V CC 2=5V
0A
Forward
×
0
0
0
+
Vref
Rs
CLK
ENABLE
CBW
W1-2 phase excitation
MOI
1-2 phase excitation
Reverse
RESET
0
1
1
Motor current waveform
14
14 8
14
14 9
14
14
12
15
11
13
10
14
STK672-080-E
STK672-080-E
V CC 2=5V
2W1-2 phase excitation
W1-2 phase excitation
(1)
(2)
(3)
6
1
0
5
4
3
2
1
7
A
AB
B
BB
RoX
Two-phase stepping motor
2W1-2 phase excitation
4W1-2 phase excitation
V CC 2=5V
Vref
Ro1
Ro2
ENABLE
RESET
1
1
V CC 1=10V to 45V
We recommend a value of about
100Ω for Ro2 to minimize the
influence of the Vref pin internal
impedance, which is 6kΩ
RoX: Input impedance: 6kΩ ±30%
Ioave
Motor current is cut off when low
SG
PG
Phase switching clock edge timing
I OL I OH
+
Rising and falling edges
Active low
Rising edge only
A13262
A13261
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