MCP1012 Primary-Side Controller

The MCP1012 provides the primary-side start-up function for the flyback converter by using an internal open-loop, peak-current-mode current regulator. During start-up, the device enables controlled power transfer to the secondary side using only a small number of external components and an integrated gate driver.

After the secondary-side controller is powered, the MCP1012 operates as a primary-side gate driver. In this mode, it accepts external Pulse commands from the secondary-side controller through an isolation medium, such as a pulse transformer or a digital optocoupler.

The MCP1012 integrates multiple protection functions to support safe converter operation. These include undervoltage lockout, overvoltage lockout protection for the VDD bias supply, overtemperature protection, and cycle-by-cycle peak current limiting. The device also provides protection against continuous conduction mode operation and supports sleep and wake-up commands for low standby power operation.