HIGH VOLTAGE CURRENT SOURCE WITH SHORT CIRCUIT PROTECTION

摘要

A current source generating a charging current and a supply voltage by charging a capacitor with the charging current. The current source has a conversion circuit converting a line voltage into a second voltage, a current generation circuit generating the charging current based on the second voltage, and a control circuit controlling the current generation circuit based on the supply voltage. The charging current is controlled to be at a first current value when the supply voltage is lower than a first threshold voltage, the charging current is controlled to be at a second current value when the supply voltage is higher than a second threshold voltage. The first threshold voltage is lower than the second threshold voltage, and the first current value is lower than the second current value.

主权项

1. A current source having an input and an output, wherein the current source is configured to receive a line voltage at the input, and to provide a charging current at the output, and wherein the charging current is provided to charge a capacitor to generate a supply voltage at the output of the current source, the current source comprising:
a conversion circuit configured to convert the line voltage into a second voltage which is lower than the line voltage; a current generation circuit configured to receive the second voltage and to generate the charging current; and a control circuit coupled to the current generation circuit, wherein the control circuit is configured to receive the supply voltage, and to control the current generation circuit based on the supply voltage; wherein the control circuit is configured to control the current generation circuit such that the charging current is at a first current value when the supply voltage is lower than a first threshold voltage and at a second current value when the supply voltage is higher than a second threshold voltage, wherein the first threshold voltage is lower than the second threshold voltage, and the first current value is lower than the second current value.