Real time compliance voltage generation for an implantable stimulator

Circuitry configured to produce a compliance voltage in an implantable stimulator device, comprising:

• a biasing circuit configured to provide a current pulse between at least one first electrode and at least one second electrode, wherein the biasing circuit is connected in series with the at least one first electrode and the at least one second electrode between a time-varying compliance voltage and a reference voltage;
• a first amplifier configured to measure a first voltage across the biasing circuit continuously during the current pulse;
• and
• regulator circuitry configured to continuously vary the compliance voltage during the current pulse in accordance with the first voltage,
• wherein the regulator circuitry comprises a waveform generator for producing a waveform,
• wherein the waveform generator receives a first optimal voltage across the biasing circuit to set a maximum amplitude of the waveform to the first optimal voltage, and
• wherein the first voltage is compared to the waveform to provide a gating signal to a pulse width modulation transistor in the regulatory circuitry.