MC9722A

MC9722 is a monolithic slave interface IC designed specifically for applications compliant with the M-Bus standard (EN1434-3). Its interface circuit accommodates potential differences between slave and master stations, and bus connections require no polarity distinction. The chip can be powered by the master station via the bus, eliminating the need for a separate power supply at the slave end and avoiding additional load on the slave's battery. During data reception, the built-in dynamic level detection circuit adapts automatically to varying bus lengths. The transmitter employs a fixed 20 mA current source. In addition to the M-Bus-compliant transceiver circuitry, the chip integrates an internal 5V (MC9722A) and 3.3V (MC9722) DC voltage regulator to support applications with different power load requirements. The MC9722 features an 8-pin design in a compact SOP8_EP package, helping to minimize PCB area while requiring minimal external components to achieve a highly reliable, high-performance M-Bus terminal bus interface.

Applications

• M-Bus slave communication systems
• Water meter, heat meter, and gas meter communication systems
• Industrial control LAN systems
• Various communication devices
• Smart home control networks

Key features

• 3.3V logic level interface
• EN1434-3 compliant (slave mode)
• Polarity-independent connection
• Integrated 5V and 3.3V voltage regulators
• Built-in multiplexed current source
• Bus high-level voltage range: 18V to 45V
• Half-duplex UART up to 9600 bps
• SOP8_EP package