Cable compensation by zero-crossing compensation current and resistor

摘要

Methods, devices, and circuits are disclosed delivering a first level of output voltage to a rechargeable battery from a battery charger, the rechargeable battery is coupled to the battery charger by a charging cable. The methods, device, and circuits may further be disclosed applying, in response to an indication of an altered output voltage, a compensation current to one or more elements of the battery charger including a zero crossing (ZC) pin and a selected resistor, the selected resistor is defined by the charging cable coupling the battery charger to the rechargeable battery, and applying the compensation current to the ZC pin and the selected resistor causes an adjustment of the output voltage from the first level of output voltage to a second level of output voltage corresponding to the voltage drop from the impedance of the selected charging cable.

主权项

1. A battery charging device comprising:
a transformer including a primary winding and an auxiliary winding; a primary-side-regulation (PSR) controller including:
a zero crossing (ZC) pin;a ZC sample module, wherein the ZC sample module samples a ZC voltage at the ZC pin to generate a sampled ZC output voltage signal;a constant voltage control (CVC) module,
comprising a CVC module output voltage; andwherein the PSR controller controls a power converter output voltage to a rechargeable battery based on the sampled ZC output voltage signal at the ZC pin; anda compensation current control module comprising:
a CVC sample-and-hold (S/H) module, wherein the CVC S/H module samples and holds the CVC module output voltage generating a sampled CVC module output voltage;a voltage-to-current generator, wherein the voltage-to-current generator is configured to generate a compensation current as a function of the sampled CVC module output voltage; andwherein the compensation current control module is coupled to the ZC pin; and an adjustable offset voltage (AOV) circuit comprising a selected resistor, wherein:
the selected resistor is selected based on a cable impedance of a selected charging cable,the selected resistor is releasably coupled to the ZC pin and the auxiliary winding, andwherein compensation current and the selected resistor generate the ZC voltage, wherein the ZC voltage corresponds to the voltage drop of the cable impedance of the selected charging cable.