Diotec Semiconductor AG

http://www.diotec.com/

Apr 15, 2024

Proactive Door Intercom with Face Recognition – Diotec's MMTL431A supplies its µController

Digital is the name of the game. Today's door intercoms offer convenient features such as facial recognition, touch screens, HD live video, smartphone app connectivity, and more. They enhance security, especially in public buildings, and provide an easy-to-use and smart solution for the private home. With dual camera technology and anti-spoofing, real faces can be distinguished from images, and people can be identified using a neural network.

All these functions work with µControllers integrated into the door module. The typical supply voltage for this module is 24 V, provided via the communication line from a remote power supply. The µControllers require a stable 3.3V supply, so extra power conversion is needed. The MMTL431A precision shunt regulator from Diotec Semiconductor allows you to build a low device-count power supply. All you need in addition to this is the Current Limiting Diode CL10MD from Diotec, two resistors, and a capacitor. The circuit is described in the datasheet of the MMTL431A, and there is also a demo board available, which can be ordered under part number 3990.