摘要 |
Apparatus and methods are disclosed for adding minimum pulse widths to the coarse resolution output of a multi-reference switching amplifier. This acts to null any detectable resultant differential by addition of a dynamic offset pulse width to the fine resolution output; thus extending operation to zero while presenting the imposed minimum pulse widths as a common-mode (null) signal. A preferred method according to the invention includes the steps of separating the input signal into coarse and fine resolution outputs, adding a minimum pulse width to the coarse resolution output; and adding a dynamic offset pulse width to the fine resolution output so as to null differential signals which would otherwise be present across the load. In terms of circuitry, a data separator is employed for separating the input signal into coarse and fine resolution outputs, and a summer adds the minimum pulse width to the coarse resolution output. Pulse-width modulation converters transform the modified coarse- and fine-resolution outputs prior to presentation to the load through routing logic.
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