an44060a Panasonic Corporation of North America, an44060a Datasheet - Page 24

• Manufacturer Part Number: an44060a
• Description: Ic For Stepping Motor Drives
• Manufacturer: Panasonic Corporation of North America

AN44060A
Usage Notes
(continued)
PHA1 pin (pin 1) and PHB1 pin (pin 2) are pulled up with 50 k to VREG. There will be no problem if the input device
In order to prevent mistakes in current detection resulting noise, this IC is provided with a pulse blanking time of 2.0
Set the value of the capacitor between the VPUMP and GND pins so that the voltage on the VPUMP pin (pin 21) will
not exceed 40 V in any case regardless of whether it is a transient phenomenon or not while the motor standing by is
started.
This IC employs a PWM drive method that switches the high-current output of the output transistor. Therefore, the IC
is apt to generate noise that may cause the IC to malfunction or have fatal damage. To prevent these problems, the
power supply must be stable enough. Therefore, the capacitance between the VREG and GND pins must be a minimum
of 1 F and the one between the VM and GND pins must be a minimum of 47 F and as close as possible to the IC so that
PWM noise will not cause the IC to malfunction or have fatal damage.
The HBM electrostatic breakdown voltage (with a capacitance of 100 pF and a resistance of 1.5 k ) of BC1 pin
(pin 19) is approx. 1500 V.
On the other hand, the minimum MM electrostatic breakdown voltage (with a capacitance of 200 pF and a resistance
of 0 ) applicable to all pins is 250 V.
connected to this IC is a microcontroller operating at 5 V. If the microcontroller used operates at a voltage less than 5
V (e.g., 3.3 V), however, a problem may result, because 5 V will be applied to the microcontroller output pin when the
pin is at high impedance, which may be in excess of the dielectric strength of the microcontroller.
If a state of high impedance is likely to occur, pull down PHA1 pin (pin 1) and PHB1 pin (pin 2) with appropriate resistance
for the protection of the microcontroller.
time of minute current control.
The graph on the right-hand side shows
the relationship between the pulse blanking time
and minute current value.
The increase or decrease in the motor current is
determined by the resistance of the internal winding
of the motor.
s (typ.). The motor current will not be less than the current determined by blanking time. Pay utmost attention at the
RCS current waveform when the set
current is less than the minimum current
RCS current waveform
while in normal operation
SFA00002AEB
T
(See No. 20 of Electrical Characteristics.)
f
(See No. 19 of Electrical Characteristics.)
PWM
B
: Pulse blanking time
: PWM frequency
Minimum current
Set current
Set current
T
B
f
PWM
1
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