Implantable nerve stimulator having internal electronics without ASIC and methods of use

An implantable neurostimulator system for delivering one or more electrical pulses to a target region within a patient's body, the implantable neurostimulator system comprising:

• an implantable lead comprising a plurality of electrodes located on a distal end of the lead, wherein the electrodes are positionable proximate to a target region within a patient's body to provide electrical stimulation to the target region;
• an implantable pulse generator electrically coupled to a proximal end of the lead, wherein the implantable pulse generator comprises:
• a bio-compatible housing defining a hermetically sealed internal volume;
• a rechargeable power supply disposed within the hermetically sealed internal volume of the bio-compatible housing;
• and
• stimulation circuitry disposed within the hermetically sealed internal volume of the bio-compatible housing, wherein the stimulation circuitry is electrically coupled to the rechargeable power supply and configured to generate one or more electrical pulses, wherein the stimulation circuitry comprises a first differential amplifier having inputs coupled to a current command and a constant voltage supply, the first differential amplifier configured to selectively source current to the lead and to selectively sink current from the lead to thereby generate one or more electrical pulses.