Current sensing multiple output current stimulators
First Claim
1. An implantable neurostimulation system comprising:
- a pulse generator comprising;
a multiple output current stimulator circuit comprising;
a current source;
a first resistor coupled to the current source to provide a reference voltage;
at least one output side transistor having a current output terminal for providing an output current;
a second resistor coupled between a voltage source and the at least one output side transistor to thereby provide a common sensing voltage; and
a differential amplifier comprising;
a first input coupled to the reference voltage;
a second input coupled to the common sensing voltage; and
an output arranged to drive the at least one output side transistor as a function of the difference between the reference voltage and the common sensing voltage.
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Accused Products
Abstract
A multiple output current stimulator circuit with fast turn on time is described. At least one pair of input side and output side transistors is arranged in a current mirror connected to a supply transistor by cascode coupling. The output side transistor supplies stimulation current to an electrode in contact with tissue. An operational amplifier connected to a reference voltage and to the output side transistor drives the supply transistor to maintain the voltage at the output side transistor equal to the reference voltage. The at least one pair of transistors includes multiple pairs of transistors whose output side transistors drive respective electrodes with stimulation currents. The stimulator determines the initiation and duration of stimulation current pulses supplied to each electrode. At circuit activation, large currents are generated which discharge capacitances in the output side transistors causing rapid output side transistor turn on.
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Citations
17 Claims
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1. An implantable neurostimulation system comprising:
a pulse generator comprising; a multiple output current stimulator circuit comprising; a current source; a first resistor coupled to the current source to provide a reference voltage; at least one output side transistor having a current output terminal for providing an output current; a second resistor coupled between a voltage source and the at least one output side transistor to thereby provide a common sensing voltage; and a differential amplifier comprising;
a first input coupled to the reference voltage;
a second input coupled to the common sensing voltage; and
an output arranged to drive the at least one output side transistor as a function of the difference between the reference voltage and the common sensing voltage.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
Specification