ata5830 ATMEL Corporation, ata5830 Datasheet - Page 13

• Manufacturer Part Number: ata5830
• Description: Intelligent Stepper Motor Driver
• Manufacturer: ATMEL Corporation

Step Operation
Chopper Current Control
4575B–BCD–01/03
If the chip temperature exceeds the overtemperature warning threshold, the step speed
is reduced to 300 Hz. If the chip temperature rises further the output driver is shut off.
Table 4. Maximum Step Frequency
The stepping motor is operated in halfstep-compensation mode. The current for both
coils is shown in Figure 12. The current levels are increased when the temperature is
below 0°C to secure operation. For final tests at the end of the application production
line the currents are reduced.
Figure 12. Compensated Halfstep Operation
The chopper current control is shown in Figure 13. The current is turned on every 40 µs
(25 kHz chopper frequency). The current flow in the H-bridge is shown in Figure 14a.
After a blanking time of 2.5 µs to suppress turn-on peaks the current is measured via the
shunt voltage. As soon as the current has reached its nominal value it is turned off
again. The current flow in this state is shown in Figure 14b.
V
< 9 V
9 V to 9.5 V
9.5 V to 10 V
10 V to 10.5 V
10.5 V to 11 V
> 11 V
> 20 V
BAT
coil B
coil A
-500mA
-700mA
-500mA
-700mA
700mA
500mA
700mA
500mA
1
Maximum Step Frequency
at Rising Voltage
No operation
No operation
No operation
No operation
850 Hz (1.17 ms)
1000 Hz (1 ms)
No operation
2
3
4
5
6
7
Maximum Step Frequency
(V
No operation
300 Hz (3.33 ms)
500 Hz (2.03 ms)
680 Hz (1,47 ms)
850 Hz (1.17 ms)
1000 Hz (1 ms)
No operation
BAT
once > 10.5 V)
8
half steps
half steps
ATA6830
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