SNVS480J January 2007 – July 2020 LM5022
An internal high gain error amplifier is provided within the LM5022. The noninverting input of the amplifier is internally set to a fixed reference voltage of 1.25 V. The inverting input is connected to the FB pin. In non-isolated applications such as the boost converter the output voltage, VO, is connected to the FB pin through a resistor divider. The control loop compensation components are connected between the COMP and FB pins. For most isolated applications, the error amplifier function is implemented on the secondary side of the converter and the internal error amplifier is not used. The internal error amplifier is configured as an open-drain output and can be disabled by connecting the FB pin to ground. An internal 5-kΩ pullup resistor between a 5-V reference and COMP can be used as the pullup for an opto-coupler in isolated applications.