Input transient protection and reverse protection for inverters

A protection circuit for protecting an input of an inverter circuit, comprising:

• a transient protection circuit coupled between a direct current (DC) voltage source and a positive input terminal and a negative input terminal of the inverter circuit to protect the inverter circuit, in response to a surge of a DC voltage received from the DC voltage source, wherein the inverter circuit includes an input and an output, wherein the inverter circuit is configured to receive the DC voltage at the input and convert the DC voltage to an alternating current (AC) voltage at the output, wherein the transient protection circuit comprises:
• a field-effect transistor (FET) coupled across the input of the inverter circuit,
• a first Zener diode coupled between a positive input of the inverter circuit and the FET, and
• a second Zener diode coupled between a negative input of the inverter circuit and the FET;
• a reverse protection circuit coupled between the positive input terminal and the negative input terminal and the input of the inverter circuit to provide reversed voltage protection to the inverter circuit in response to detecting a reversal of the DC voltage applied to the input of the inverter circuit;
• a current limit circuit coupled to the output of the inverter circuit, the current limit circuit generating a current feedback signal based on a summation of a signal from the output of the inverter circuit and a ramp signal;
• a driver circuit coupled to the inverter circuit and an output of the current limit circuit, the driver circuit is configured to turn on or turn off the inverter circuit pulse-by-pulse based on at least the current feedback signal from the current limit circuit;
• a pulse width modulation (PWM) controller coupled to the current limit circuit, the PWM controller to provide a PWM signal to the current limit circuit, wherein the ramp signal is generated based on the PWM signal;
• and
• a comparator circuit to generate a comparison signal based on the current feedback signal and a slope compensation signal, wherein the slope compensation signal is generated based on a predetermined reference signal and the PWM signal, and the driver circuit is configured to turn on or turn off the inverter circuit pulse-by-pulse based on the comparison signal.