摘要 |
Disclosed herein are circuits and methods for generating a compliance voltage from a battery voltage in an implantable stimulator device. In one embodiment, the battery voltage is boosted to form the compliance voltage for driving the current sources (DACs) that provide therapeutic current to the electrodes on the device. Such improved boosting circuitry is preferably cascaded and comprises two stages. The first stage is preferably a step-up converter, which is used to generate an intermediate voltage from the battery voltage. The second stage is preferably a charge pump, which is used to generate the compliance voltage from the intermediate voltage. By splitting the boosting into stages, power efficiency during generation of high voltages is improved compared to the use of step-up converters and resolution in setting the compliance voltage is improved compared to the use of charge pumps alone. Moreover, depending on the compliance voltage to be produced by the boosting circuitry, the various stages can be selectively activated.
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