US 5,710,499 A · Stepper motor control circuit and method

Abstract

A stepper control circuit and method for providing improved stepper motor control is provided. In a first embodiment, output drivers having three states are used to drive the coil terminals of an exemplary stepper motor. The use of the three state output drivers provides rapid discharge of the current stored in the coils of the motor, allowing faster operation of the stepper motor, and prevents erroneous skipping of steps, as occurred with prior art circuitry. A detailed implementation of the preferred embodiment is described. An integrated circuit including the stepper motor control circuitry of the first preferred embodiment is described. Other devices, systems and methods are also disclosed.

Claims19

Dependent claims

A stepper motor control circuit, comprising:

output driver circuitry for driving the coils of a motor to predetermined potentials, responsive to control signals;
and
logic decode circuitry coupled to one or more direction inputs, and outputting control signals to said output driver circuitry to cause the output driver circuitry to drive the coils of the stepper motor to predetermined potentials in a particular sequence so that the stepper motor moves in predetermined steps;
wherein said output driver circuitry selectively drives the coils of said stepper motor to a high impedance state, the output driver circuitry further providing a fast flux discharge path while said coils are in said high impedance state.

1 more element

An integrated circuit for controlling a stepper motor, comprising:

input terminals for receiving at least a directional control input;
output terminals for driving coils of the stepper motor for controlling the direction and stepping action of said stepper motor;
output circuitry coupled to said output terminals for selectively outputting predetermined potentials to said coils of said stepper motor responsive to control signals, said predetermined potentials including a high impedance state;
and
control circuitry coupled to said input terminals and outputting said control signals to said output circuitry, said control circuitry causing said output circuitry to drive the coils of said stepper motor to predetermined potentials in a predetermined sequence, responsive to said directional control input;
wherein said output circuitry provides a path to rapidly discharge flux from the coils of said stepper motor when said output circuitry is in said high impedance state.

3 more elements

Dependencies are inferred from the claim text.

Stepper motor control circuit and method

Life of this patent

Stepper motor control circuit and method

Life of this patent

Abstract

Claims19