Pulse-by-pulse compliance voltage generation for an implantable stimulator

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

• a source circuit coupled to a compliance voltage, wherein the source circuit is configured to provide a first current pulse to at least a first electrode;
• a sink circuit coupled to a reference voltage, wherein the sink circuit is configured to sink the first current pulse from at least a second electrode;
• a first amplifier configured to measure a first analog voltage across the source circuit;
• a second amplifier configured to measure a second analog voltage across the sink circuit;
• a first reference voltage generator configured to produce an optimal first analog voltage;
• a second reference voltage generator configured to produce an optimal second analog voltage;
• a first comparator configured to compare the measured first analog voltage to the optimal first analog voltage and to produce a first digital signal indicating whether the measured first analog voltage is high or low relative to the optimal first analog voltage;
• a second comparator configured to compare the measured second analog voltage to the optimal second analog voltage and to produce a second digital signal indicating whether the measured second analog voltage is high or low relative to the optimal second analog voltage;
• logic circuitry configured to assess the first and second digital signals, and configured to issue a control signal;
• and
• regulator circuitry configured to adjust the compliance voltage in accordance with the control signal.