| 摘要 |
An error signal isolator circuit for conveying an error signal across an electrical isolation boundary such as an external pulse transformer employs a level shifting process whereby a controllable voltage is measured with respect to a reference voltage and, with any gain implemented in the process, is level shifted upward such that the higher potential is referenced to a supply voltage and the lower potential is used dynamically to control the magnitude of voltage conveyed in a pulse amplitude modulation (PAM) process. In the PAM process, an ON pulse is terminated by monitoring when a PAM current has increased to a predetermined and controllable level. An ON pulse is initiated by monitoring when the voltage across a clamp diode has decayed below its normal forward bias level, indicating a commensurate decay in PAM current, following termination of the previous ON pulse.
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