Worcester, Mass.—Allegro MicroSystems' A3969, a dual full-bridge pulse-width modulated (PWM) motor IC for driving both windings of a two-phase bipolar stepper motor, feature the company's Satlington output structure, which combines the low voltage drop of a saturated transistor and the high peak current capability of a Darlington stage.

The device's two H-bridges, rated at up to 30 volts, can deliver up to ± 650 mA. The motor winding current is set using the device's fixed-frequency, current-control circuitry. The peak load current limit is set by means of a reference voltage and current-sensing resistors.

The fixed-frequency pulse duration is set by a user-selected external RC timing network. The capacitor in the RC timing network also determines the blanking window, which prevents false triggering of the PWM current control circuitry during switching transitions.

Each bridge has a PHASE input that's used to select the appropriate source and sink pair. The ENABLE input, when high, disables the output drivers. Internal circuit protection includes thermal shutdown with hysteresis, ground-clamp and flyback diodes, and crossover-current protection.

Click here for the product datasheet. The A3969, in a 5-by-5 mm, 28-pin quad MLP/QFN Pb-free plastic package with exposed thermal pad and 100% matte tin leadframe plating, is priced at $1.23 each in quantities of 1,000. Typical lead time is 12 weeks.

Allegro MicroSystems, 1-508-853-5000, www.allegromicro.com