2 Wire XTR Products NOT FOR 3 Wire

2 -Wire XTR Products NOT FOR 3 -Wire XTR Applications 1

4 to 20 m. A Current Loop Needs only 2 Wires (normally loosely twisted, sometimes shielded) for all of these functions: 1. Sensor Excitation 2. Signal Conditioning 3. Signal Transmission jm-Sept 05 2

4 to 20 m. A Current Loop Supply Voltage XTR Sensor Signal Conditioning XTR VS Signal Converter and Supply X Signal Receivers: VS=I*R RCV 1 Signal Current Output jm-Sept 05 RCV 2 RCV n 3

4 to 20 m. A Current Loop Supply Voltage XTR • Supply Voltage nominal 24 V • Min: +12 V (sometimes as low as +7 V) • Max: +36 V (short time over-voltage +40 V) Power supply for the XTR and the Sensor is derived from the minimum current <4 m. A (<3. 4 m. A) and the sub-regulated supply voltage. jm-Sept 05 4

4 to 20 m. A Current Loop Standard Specification XTR • Signal Current Range: 4. 0 to 20. 0 m. A • Error Signaling Range: 3. 4 to 4 m. A and 20 to 24 m. A These under and over ranges are used to indicate error conditions of the sensor: wire break, short, over-load, excitation failure. There is a “NAMUR” specification, which specifies these special ranges. jm-Sept 05 5

4 to 20 m. A Current Loop Power Dissipation XTR • Power dissipation of the XTR is calculated from the voltage across the XTR and the current flowing. • Examples: 24 Vsupply – (20 m. A*500 W) = 14 V P = 14 V * 20 m. A = 280 m. W 36 Vsupply – (20 m. A*50 W) = 35 V P = 35 V * 20 m. A = 700 m. W We use an external power transistor to get the heat out of the IC. jm-Sept 05 6

4 to 20 m. A Current Loop Circuit Protection XTR Protection against harsh industrial environment: + Supply XTR Signal Out jm-Sept 05 7

4 to 20 m. A Current Loop Why “Current” XTR Constant current generates a constant voltage across a “Shunt” resistor – – – Insensitive to wire resistance Insensitive to multiple receivers (shunts) Insensitive to conducted noise Easy signal filtering Low cost wiring ( just 2 wires) Used in Industry since many years It will remain STANDARD for many years, because: – Lower cost than digital signal transmission – Better noise immunity – Longer distance ( >1 km) jm-Sept 05 8

4 to 20 m. A Current Loop HART Protocol XTR • HART is a digital protocol which can be modulated onto the 4 to 20 m. A signal wires. • It is used where remote sensor programming is required (“Smart Sensor”) • HART puts several restrictions to the wiring, wire length, shunt resistance and supply voltage. jm-Sept 05 9

3 -Wire Connection Supply Voltage XTR Sensor jm-Sept 05 Sensor Signal Conditioning Signal Converter (and Supply) Signal Receiver 12

Current or Voltage Transmitter XTR • Many sensors are connected via 3 Wires: +Supply, GND, Signal Do not mix with the 2 -wire 4 to 20 m. A current loop ! Popular signals for these active sensors are: “V” 0 to +10 V, 0 to +5 V “I” 0 to +20 m. A ( 24 m. A ), 4 to 20 m. A ( 3. 4 to 24 m. A ) The current signal is compatible to the “ 4 to 20 m. A current loop” signals. jm-Sept 05 13

3 -Wire Current Transmitter XTR • XTR 110 (“old” product) • XTR 111 ( New Product in planning !) +24 V Output Disable Reg. Out I-Mirror DRV Output Failure - SENSE + VREF Signal Input I 1 IOUT + - 0 to 20 m. A (4 to 20 m. A) GND RSET IOUT = VIN/RSET * 10 IOUT = 10*I 1 jm-Sept 05 • External Resistor R 1 allows flexible setup to a wide range of output currents. • Supply max : 44 V, nominal: 24 V. • Supply min: < 9 V • Current compliance stretches well below GND ( external transistor) • I 1 defined by ext. R 1. I 2 = 10 * I 1 • Regulator output: <5 m. A • Package: DFN-10 [3 x 3 mm] • Internet Price: $1. 45 (@1 kpcs) • RTM: Q 2 2006 14

3 -Wire Voltage Transmitter Discrete solution Supply Voltage (PGA 309. . . ) Sensor Signal Conditioning “XTR” Signal + OPA - Signal Receiver Driver Op Amp (and Supply) R 2 1 k R 1 1 k jm-Sept 05 16

3 -wire Transmitter Current or Voltage Output “XTR” digitally selectable Supply Voltage (PGA 309. . . ) Sensor Signal Conditioning Signal XTR 300 Signal Receiver XTR 300 and Supply jm-Sept 05 17

Normal 2 -Wire Operation of XTR 115 Input Signals & Feedback Voltage, VR 2, referenced to Iret Feedback Voltage, VR 2 is negative with reference to Iret Op Amp Circuit Loop Gain forces A 1+ = A 1 - = Iret = 0 V IIN = VIN / RIN + Vref / Roffset IR 1 = IIN * R 1 = VR 2 = Iout / R 2, Op Amp Loop Controls Iout to Create VR 2 Iout = VR 2 /R 2 tg-Sept 05 18

3 -Wire 4 -20 m. A NOT for XTR 115 (or any 2 -Wire XTR!) Current cannot flow through R 2 in the right direction to create 0 V at A 1+ (Need VR 2 to be negative referenced to Iret) T 1 drives current into ground at Iout over-current limit of 41 m. A tg-Sept 05 though RL !! No current 19

4 -20 m. A Transmitter Design Solutions Ø 2 -Wire General Purpose Ø 3 -Wire General Purpose Ø 4 -20 m. A Current Loop Receiver Ø 2 -Wire RTD Conditioners üwith Linearization Ø 2 -Wire Bridge Sensor Conditioners üwith Linearization Ø 2 -Wire RTD Conditioner üwith Digital Cal (Linearization, Span, Offset) tg-Sept 05 20

2 -Wire General Purpose Sensor Excitation Loop Voltage (V) Full-Scale Input Range Output Range (m. A) Additional Power Available Package Price 1 k $USD 5 m. V to 1 V 4 -20 --- DIP-14 SOIC-16 7. 34 Device Description XTR 101 IA + Current Excitation Two 1 m. A 11. 6 to 40 XTR 115 IIN to IOUT Converter. External Resistor Scales VIN to IIN. VREF=2. 5 V 7. 5 to 36 40μA to 200μA 4 -20 5 V@4 m. A SOIC-8 0. 95 XTR 116 IIN to IOUT Converter. External Resistor Scales VIN to IIN. VREF=4. 096 V 7. 5 to 36 40μA to 200μA 4 -20 5 V@4 m. A SOIC-8 0. 95 tg-Sept 05 21

XTR 115 / XTR 116 tg-Sept 05 22

3 -Wire General Purpose Device Description XTR 110 Selectable Input/Output Ranges Sensor Excitation VREF=10 V Loop Voltage (V) Full. Scale Input Range 13. 5 to 40 0 V to 5 V 0 V to 10 V Output Range (m. A) Additiona l Power Available Package Price 1 k $USD 4 -20, 0 -20, 5 -25 --- DIP-16 6. 35 XTR 110 tg-Sept 05 23

4 -20 m. A Current Loop Receiver Device Description RCV 420 4 -20 m. A input, 0 -5 V Output, 1. 5 V Loop Drop tg-Sept 05 Sensor Excitation Loop Voltage (V) Full-Scale Input. Range (m. A) Output Range (V) Additional Power Available Package Price 1 k $USD VREF=10 V +11. 5/-5 to +/-18 4 -20 0 -5 V --- DIP-16 3. 34 24

2 -Wire RTD Conditioner with Linearization Device Description XTR 105 100Ω RTD Conditioner XTR 112 1 kΩ RTD Conditioner XTR 114 10 kΩ RTD Conditioner tg-Sept 05 Sensor Excitation Loop Voltage (V) Two 800μA 7. 5 to 36 Two 250μA 7. 5 to 36 Two 100μA 7. 5 to 36 Full-Scale Input Range 5 m. V to 1 V Output Range (m. A) 4 -20 Additional Power Available Package Price 1 k $USD 5. 1 V@1 m. A DIP-14 SOIC-14 3. 75 25

2 -Wire Bridge Sensor Conditioner with Linearization Device Description Sensor Excitation Loop Voltage (V) XTR 106 Bridge Conditioner 5 V and 2. 5 V 7. 5 to 36 tg-Sept 05 Full-Scale Input Range Output Range (m. A) Additional Power Available Package Price 1 k $USD 5 m. V to 1 V 4 -20 5. 1 V@1 m. A DIP-14 SOIC-14 3. 75 26

2 -Wire RTD Conditioner with Digital Cal for Linearization, Span, Offset Device Description Sensor Excitation XTR 108 100Ω to 1 kΩ RTD Conditioner w/6 -Channel Input Mux. Extra Op Amp can convert to Voltage Sensor Excitation. Two 500μA Programmable tg-Sept 05 Loop Voltage (V) Full-Scale Input Range Output Range (m. A) 7. 5 to 24 5 m. V to 320 m. V 4 -20 Additional Power Available Package Price 1 k $USD 5. 1 V @ 2. 1 m. A SSOP-24 3. 75 27

RTD IN & 4 -20 m. A OUT w/Digital Calibration tg-Sept 05 28

XTR 108 Key Features • 10Ω to 10 kΩ RTD Conditioner • RTD Compensation ü Offset, Span, Non. Linearity • 0. 1% Post-Calibration Accuracy • -40°C to +85°C Range • Loop Voltage: 7. 5 V to 40 V • SPI Interface Digital Calibration/Configuration • 6 Channel Input Mux ü Allows for up to 5 different Zero set points • Internal/External VREF • Undedicated Spare Op Amp • Uses Standard External SPI 1 k EEPROM (8 -SOIC Package) • Can be used in 3 -Wire 4 -20 m. A systems (Voltage Out Mode) • 5. 1 V Sub-Regulated Output • SSOP-24 Package • $3. 35 @1 k tg-Sept 05 29

XTR 108 EVM & Development Tools XTR 108 EVM Control/Program Software XTR 108 Resistor Selection Tool XTR 108 EVM User’s uide XTR 108 Quick. Start Guide Detailed, Step-by-Step System Calibration “Definition by Example” tg-Sept 05 30

New & Improved XTR 108 EVM utput Low Nois e Ha Calibratio rdw a re D n Accura esig n cy to <0. 1 % Voltage O ent cem n a h n E e Mod tg-Sept 05 Evaluate XTR 108 with your RTD Software Calibration/Control for XTR 108 Available NOW! 31

XTR 108 Modification for 3 -Wire Voltage (or Current) Output XTR 108: PTC [PT 10 – PT 10000] Sensor Front-End VOUT See NEW data sheet for details (page 25) jm-Sept 05 32

XTR 117, 4 -20 m. A Transmitter Ø Ø Ø Ø Ø High Accuracy: Low Span & Offset Errors Easily interfaced with sensors or circuitry Simple Over-Scale signaling Regulated 5 V power for External Circuitry Minimal power consumption: 250µA Wide Operating Voltage range: +7. 5 V to +40 V Tolerant of power supply surges up to +50 V Gain of 100 x to reduce noise sensitivity Miniature MSOP-8 package $0. 90 USD @ 1 k Qty tg-Sept 05 Ø Ø Ø Accuracy without calibration Noise resistant signaling Robust in harsh electrical environments A generous 3. 75 m. A available for sensor circuitry Requires minimal board space Unbeatable: Cost/Size/Performance benefits Ø Pressure Transducers Ø Temperature Transducers Ø Humidity Transducers Ø Industrial Process Monitors Ø PGA 309 4 -20 m. A Output Converter (Convert Voltage-Out to Current-Out) 33

Complete 4 -20 m. A Sensor Conditioner Digital Calibration of Sensor Linearity, Span, Offset, Tempcos PGA 308 tg-Sept 05 & XTR 117 34