STK672-210 Sanyo Semicon Device, STK672-210 Datasheet - Page 7

• Manufacturer Part Number: STK672-210
• Description: Two-Phase Stepping Motor Driver Output Current: 1.4 A
• Manufacturer: Sanyo Semicon Device

The constant-current control time t2, and the time T (= t1 + t2 + t3) that the phase signal is on in each excitation mode
are as follows.
Determine the values for Vsat and Vdf by substitution using the graphs for Vsat vs I
current value for I
for the STK672-210 by comparison with the ∆Tc vs. Pd graph.
Note that it is necessary to check the temperature rise in the actual application system case, since the STK672-210
substrate temperature Tc changes with the air convection conditions around the STK672-210 when a heat sink without
fins is used.
t1: The time until the winding current reaches its rated current (I
t2: The time in the constant-current control (PWM) region
t3: The time from the point a phase signal is cut until the back EMF current is dissipated.
t1 = (–L/(R + 0.77) ln (1 – ((R + 0.77)/V
t3 = (–L/R) ln ((V
V
L: Motor inductance (H)
R: Motor winding resistance (Ω)
I
2 phase excitation mode: t2 = (2/Clock) – (t1 + t3)
1-2 phase excitation mode: t2 = (3/Clock) – t1
OH
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
CC
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
: Set motor output current wave height (A)
0
0
1: Motor supply voltage (V)
0.2
0.4
0.5
OH
0.6
. Then judge whether or not a heat sink is required from the determined average power dissipation
Motor current, I OH — A
CC
Output current, I O — A
0.8
1 + 0.77)/(I
Vref — I OH
Vsat — I O
1.0
1.0
1.2
1.5
OH
1.4
1.6
R + V
CC
2.0
1.8
1) I
CC
ITF02291
ITF02293
2.0
1 + 0.77)
STK672-210
OH
2.5
2.2
)
OH
1000
100
1.0
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
10
)
0
7
5
3
2
7
5
3
2
7
5
3
2
0
0
0.2
20
0.4
Substrate temperature, Tc — C
0.6
Output current, If — A
40
0.8
OH
I IH — Tc
Vdf — If
1.0
and Vdf vs I
60
1.2
1.4
80
1.6
I IH
I IL
OH
1.8
100
for the set
No.7464-7/8
ITF02292
ITF02294
2.0
120
2.2