1FEATURES

• Meter-Bus Transceiver (for Slave) Meets

Standard EN1434-3

• Receiver Logic With Dynamic Level

Recognition

• Constant-Current Sink Adjustable By Resistor

• Polarity Independent

• Power-Fail Function

• Module Supply Voltage Switch

• 3.3-V Constant Voltage Source

• Up to 9600 Baud in Half Duplex for UART

Protocol

• Slave Power Support

– Supply From Meter-Bus by Output VDD

– Supply From Meter-Bus by Output VDD or

From Backup Battery

– Supply From Battery – Meter-Bus Active for

Data Transmission Only

APPLICATIONS

• E-metering

• Advanced Metering Infrastructure (AMI)

• Water Meters

• Gas Meters

• Heat Meters

DESCRIPTION

The TSS521 device is a single-chip transceiver

developed for Meter-Bus standard (EN1434-3) applications.

The TSS521 interface circuit adjusts the different

potentials between a slave system and the Meter-Bus master. The connection to the bus is polarity

independent and supports full galvanic slave isolation

with optocouplers.

The circuit is supplied by the master through the bus.

Therefore, this circuit offers no additional load for the

slave battery. A power-fail function is integrated.

The receiver has dynamic level recognition, and the

transmitter has a programmable current sink.

A 3.3-V voltage regulator with power reserve for a

delayed switch off at bus fault is integrated.