FEATURES

? Full-Step, Half-Step and Micro-Step

Capability.

? Bipolar Output Current up to 2A.

? Wide Range of Motor Supply Voltage:

10–50V

? Low Saturation Voltage

? Wide Range of Current Control: 5mA–2A.

? Current Levels Selected in Steps or Varied

Continuously.

? Thermal Protection and Soft Intervention.

DESCRIPTION

The UC3770A and UC3770B are high-performance full bridge drivers

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 shutdown,

and a power H-bridge output stage. Two UC3770As or

UC3770Bs and a few external components form a complete microprocessor-

controllable stepper motor power system.

Unlike the UC3717, the UC3770A and the UC3770B require external

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°C

to 70°C ambient.