Driver circuit for use with inductive loads or the like

A single chip integrated circuit for providing current from a power supply to an inductive load, comprising:

• power stage means coupled with the power supply having an output adapted to be coupled to the inductive load and including internal current sensing means for sensing the magnitude of the load current;
• comparator means having first and second inputs and outputs respectively, said first input being adapted to receive a reference signal, said second input being coupled to said current sensing means, said first output being coupled to an input of said power stage means, said comparator being responsive to said reference signal being of a first predetermined magnitude for rendering said power stage conductive to thereby provide current to the inductive lead, said comparator means being responsive to the load current reaching a predetermined peak magnitude for producing an output signal at said first and second outputs such that said power stage means becomes abruptly less conductive to reduce the load current;
• bistable reference circuit means which is responsive to an alternating input signal supplied to the integrated circuit for supplying a reference current of a first value at an output, said bistable reference circuit means being responsive to said output signal produced at said second output of said comparator means for supplying a reference current at said output of a second value whereby the load current is reduced to a level representative of the second value of said reference current;
• and
• circuit means coupled to said output of said bistable reference circuit means and said first input of said comparator means for converting said reference current provided from said bistable reference circuit to said reference signal applied to said comparator means.

A monolithic integrated circuit for providing current to the coil of an injector valve, comprising:

• power supply conductor means adapted to receive an applied source of operating potential;
• power stage means having an input and an output, said output being coupled to an output of the circuit to the coil for supplying current thereto including current sensing means for sensing the magnitude of the current through the coil;
• bistable reference means responsive to a first input signal for producing a first output current of a first value and responsive to a second input signal for producing a second output current of a second value;
• circuit means having first and second inputs and outputs, said first input being coupled to an input of the circuit, said first output being coupled to said bistable reference means, said second output being coupled to said input of said power stage means, said circuit means being responsive to an applied input signal being in a first level state for producing a first logic signal at said first and second outputs such that said bistable reference means is caused to produce said first output current and said power stage means is maintained in a non-conductive state, said circuit means being responsive to said applied input signal being in a second level state wherein said power stage means is no longer inhibited from conducting;
• and
• comparator means having first and second inputs and outputs, said first input being coupled to the output of said bistable reference means, said second input being coupled to said current sensing means, said first output being coupled to said input of said power stage means, said second output being coupled to said second input of said circuit means, said comparator means being responsive to said first output current from said bistable reference means when said applied input signal is in said second level state for rendering said power stage conductive and being responsive to said load current through said current sensing means reaching a peak magnitude indicative of said first output current from said bistable reference means for generating output signals at said first and second outputs respectively such that said circuit means produces said second input signal to said bistable reference means and said power stage means is caused to become less conductive until the magnitude of load current reaches a level indicative of said second output current from said bistable reference circuit means.

An integrated circuit for supplying a multi-level current to a load coupled thereto in response to an input signal supplied to the circuit, comprising:

• power stage means responsive to a drive signal for supplying the load current to the load including current sensing means for sensing a proportional amount of said load current;
• reference current source means responsive to the input signal for providing a reference current of either a first or a second predetermined magnitude;
• and
• comparator means coupled with said reference current source means and said load current sensing means which is responsive to said sensed load current being of less magnitude than said reference current of said first magnitude for supplying a drive signal to said power stage means such that a load current of a first level is supplied to the load, said comparator means being responsive to the sensed load current reaching a magnitude representative of said reference current of said first magnitude for causing said reference current source means to provide said current of said second magnitude and to provide a reduced drive signal to said power stage means such that the load current is reduced to a second level representative of said reference current of said second magnitude.