Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsInterface ICsInterface IC - transceivers M-Bus 1/1 SOIC 16 N

RXI

RIS

GND

BUSL1

RIDD

STC

BUSL2

D PACKAGE

(TOP VIEW)

VDD

TXI

BATTX

TSS721A

www.ti.com

................................................................................................................................................ SLAS222A –APRIL 1999–REVISED SEPTEMBER 2009

METER-BUS TRANSCEIVER

Check for Samples: TSS721A

FEATURES

• Meter-Bus Transceiver (for Slave) Meets

Standard EN1434-3

• Receiver Logic With Dynamic Level

Recognition

• Adjustable Constant-Current Sink via Resistor

• Polarity Independent

• Power-Fail Function

• Module Supply Voltage Switch

• 3.3-V Constant Voltage Source

• Remote Powering

• Up to 9600 Baud in Half Duplex for UART

Protocol

• Slave Power Support

– Supply From Meter-Bus via Output VDD

– Supply From Meter-Bus via Output VDD or

From Backup Battery

– Supply From Battery – Meter-Bus Active for

Data Transmission Only

DESCRIPTION

TSS721A is a single chip transceiver developed for Meter-Bus standard (EN1434-3) applications.

The TSS721A 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 via 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.

ORDERING INFORMATION

(1) (2)

PACKAGE ORDERABLE PART NUMBER

0°C to 70°C SOIC – D Reel of 2500 TSS721ADR

(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI

web site at www.ti.com.

(2) Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (14 pages)

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TSS721A www.ti.com................................................................................................................................................
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TSS721A SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009................................................................................................................................................ www.ti.com FUNCTIONAL DESCRIPTION Functional Schematic CS1 VB IBUS ICI2 PF TC2 RIDD ICS3 BAT VF ISTC STC ISTC_use BUSL1 BR ICI1 BUSL2 CS2 TX TC3 TXI SC VS TC1 IMS VDD IVDD VVDD 3.3 V REF2 1.3 V REF1 7V CS3 ECHO RVS RX TC4 RXI RIS GND TERMINAL FUNCTIONS TERMINAL DESCRIPTION NAME NO.
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TSS721A www.ti.com................................................................................................................................................ SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009 Data Transmission, Master to Slave The mark level on the bus lines VBUS = MARK is defined by the difference of BUSL1 and BUSL2 at the slave. It is dependent on the distance of Master to Slave, which affects the voltage drop on the wire.
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TSS721A SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009................................................................................................................................................ www.ti.com Data Transmission, Slave to Master The device uses current modulation to transmit information from Slave to the Master while the bus voltage remains constant. The current source CS3 modulates the bus current and the master detects the modulation.
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TSS721A www.ti.com................................................................................................................................................ SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009 Slave Supply 3.3-V The TSS721A has an internal 3.3-V voltage regulator. The output power of this voltage regulator is supplied by the storage capacitor CSTC at pin STC. The storage capacitor CSTC at pin STC is charged with constant current ISTC_use from the current source CS1.
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TSS721A SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009................................................................................................................................................ www.ti.com Power On/Off VBUS VVB =VSTC + 0.6 V typical threshold voltage for power fail PF ton VSTC VDDon VDDoff VVS VVDD VPF toff Figure 5. Power On/Off Timing Power Fail Function Because of the rectifier bridge BR at the input, BUSL1, and BUSL2, the TSS721A is polarity independent.
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TSS721A www.ti.com................................................................................................................................................ SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009 ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) VMB Voltage, BUSL1 to BUSL2 ±50 V RX and RXI –0.3 V to 5.
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TSS721A SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009................................................................................................................................................ www.ti.
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TSS721A www.ti.com................................................................................................................................................ SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009 APPLICATION INFORMATION Remote Supply SENSOR SYSTEM (e.g.
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TSS721A SLAS222A – APRIL 1999 – REVISED SEPTEMBER 2009................................................................................................................................................ www.ti.com Remote Supply 11 9 10 5 12 13 8 7 SENSOR C SSC SYSTEM (e.g., MSP430) RL1 VDD BUSL1 1 BAT VS PF VB 2 TSS721A RX RXI TX BUSL2 16 TXI RIS SC GND RIDD STC 6 15 14 4 3 R RIS R RIDD 220 RL2 220 + C STC C SC Remote Supply/Battery Support 11 9 10 5 12 13 8 7 T1 SENSOR + BAT C SSC SYSTEM (e.g.
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PACKAGE OPTION ADDENDUM www.ti.com 4-Nov-2009 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty TSS721AD ACTIVE SOIC D 16 TSS721ADR ACTIVE SOIC D 16 40 Lead/Ball Finish MSL Peak Temp (3) Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.