A3969 Datasheet, PDF (1/9 Pages) Allegro MicroSystems – Dual Full-Bridge PWM Motor Driver

A3969
Dual Full-Bridge PWM Motor Driver
Features and Benefits
▪ ±650 mA Continuous Output Current
▪ 30 V Output Voltage Rating
▪ Internal Fixed-Frequency PWM Current Control
▪ Satlington Sink Drivers
▪ User-Selectable Blanking Window
▪ Internal Ground-Clamp and Flyback Diodes
▪ Internal Thermal-Shutdown Circuitry
▪ Crossover-Current Protection and UVLO Protection
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Package: 28 pin QFN (suffix ET)
Approximate scale
Description
The A3969 is designed to drive both windings of a two-phase
bipolar stepper motor. The device includes two H-bridges
capable of continuous output currents of ±650 mAand operating
voltages to 30 V. Motor winding current can be controlled by
the internal fixed-frequency, pulse-width modulated (PWM),
current-control circuitry. The peak load current limit is set by
the user’s selection 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 a user-selectable blanking window that
prevents false triggering of the PWM current-control circuitry
during switching transitions.
To reduce on-chip power dissipation, the H-bridge power
outputs have been optimized for low saturation voltages. The
sink drivers feature the Allegro^® patented Satlington^® output
structure. The Satlington outputs combine the low voltage drop
of a saturated transistor and the high peak current capability
of a Darlington.
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Typical Application
56 kΩ
+3.3 V
+24 V
680 pF
+3.3 V
20 kΩ
10 kΩ
47 μF
EN2
PH2
0.5 Ω
1
21
2
20
0.5 Ω
3
19
4
LOGIC
LOGIC
18
5
17
6
16
7
V_BB
15
EN1
PH1
DS3969