鈥?/div>
Full-Step, Half-Step and Micro-Step
Capability.
Bipolar Output Current up to 2A.
Wide Range of Motor Supply Voltage:
10鈥?0V
Low Saturation Voltage
Wide Range of Current Control: 5mA鈥?A.
Current Levels Selected in Steps or Varied
Continuously.
Thermal Protection and Soft Intervention.
DESCRIPTION
The UC3770A and UC3770B are high-performance full bridge driv-
ers that offer higher current and lower saturation voltage than the
UC3717 and the UC3770. Included in these devices are LS-TTL
compatible logic inputs, current sense, monostable, thermal shut-
down, and a power H-bridge output stage. Two UC3770As or
UC3770Bs and a few external components form a complete micro-
processor-controllable stepper motor power system.
Unlike the UC3717, the UC3770A and the UC3770B require exter-
nal high-side clamp diodes. The UC3770A and UC3770B are
identical in all regards except for the current sense thresholds.
Thresholds for the UC3770A are identical to those of the older
UC3717 permitting drop-in replacement in applications where
high-side diodes are not required. Thresholds for the UC3770B are
tailored for half stepping applications where 50%, 71%, and 100%
current levels are desirable.
The UC3770A and UC3770B are specified for operation from 0擄C
to 70擄C ambient.
BLOCK DIAGRAM
UDG-92039-1
SLUS403A - FEBRUARY 2000
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