20 toode toodet
Hoiatus: viimane toode laos
Designed for bidirectional pulse-width modulated (PWM) current control
of inductive loads, the A3953S— is capable of continuous output currents to
±1.3 A and operating voltages to 50 V. Internal fixed off-time PWM current-
control circuitry can be used to regulate the maximum load current to a desired
value. The peak load current limit is set by the user’s selection of an input
reference voltage and external sensing resistor. The fixed off-time pulse
duration is set by a user- selected external RC timing network. Internal circuit
protection includes thermal shutdown with hysteresis, transient-suppression
diodes, and crossover current protection. Special power-up sequencing is not
With the ENABLE input held low, the PHASE input controls load current
polarity by selecting the appropriate source and sink driver pair. The MODE
input determines whether the PWM current-control circuitry operates in a slow
current-decay mode (only the selected source driver switching) or in a fast
current-decay mode (selected source and sink switching). A user-selectable
blanking window prevents false triggering of the PWM current-control
circuitry. With the ENABLE input held high, all output drivers are disabled.
A sleep mode is provided to reduce power consumption.
When a logic low is applied to the BRAKE input, the braking function is
enabled. This overrides ENABLE and PHASE to turn off both source drivers
and turn on both sink drivers. The brake function can be used to dynamically
brake brush dc motors.
The A3953S— is supplied in a choice of two power packages; a 16-pin
dual-in-line plastic package with copper heat-sink tabs, and a 16-pin plastic
SOIC with copper heat-sink tabs. For both package styles, the power tab is at
ground potential and needs no electrical isolation. Each package type is
available in a lead (Pb) free version (100% matte tin plated leadframe).