AM400

AM400 ANALOGMICRO | Alldatasheet

Document overview

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Technical content

analog microelectronics Februar 2006 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 1/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.3 Internet: http://www.analogmicro.de Email: info@analogmicro .de PRINCIPLE FUNCTION Amplification and conversion of differential input voltages or those referenced to ground to industrial standard current (0/4...20mA) or TYPICAL APPLICATIONS

• Transducer for sensor applications
• Analog industrial output stage for microprocessor applications
• Modular signal conditioning with digital correction (Frame ASIC [1])
• Protected output stage power network
• Impedance converter IOUT = 0/4...20mA AM400 V = 6 … 3 5 VCC I = max 10mAS Differential input voltage 400mV Input voltage referenced to ground 0...V -5VCC V = 0...V - 5V OUT CC V = 5/10VREF

analog microelectronics Februar 2006 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 2/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.3 Internet: http://www.analogmicro.de Email: info@analogmicro .de

CONTENTS

ELECTRICAL SPECIFICATIONS 4 BOUNDARY CONDITIONS 7 DETAILED DESCRIPTION OF FUNCTIONS 7 OPERATING AM400 10 General information on 2- and 3-wire applications 10 Setting the voltage gain using the voltage output 11 Setting the output current range and compensating for the offset using the current output 11 Selecting the supply voltage 11 POINTS TO NOTE: INITIAL OPERATION OF AM400 12 APPLICATIONS 13 1) Typical 3-wire application with a differential input signal 13 2) Typical 3-wire application with an input signal referenced to ground 14 3) Typical 2-wire application with a differential input signal 15 4) Application for the 16-pole version of AM400 (3-wire application) 17 BLOCK DIAGRAM, 20-POLE PINOUT AND DICE 18 BLOCK DIAGRAM AND 16-POLE PINOUT 19 EXAMPLE APPLICATIONS 20 DELIVERY 21 PACKAGE DIMENSIONS 21 FURTHER READING 21

analog microelectronics Februar 2006 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 3/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.3 Internet: http://www.analogmicro.de Email: info@analogmicro .de

FEATURES

• Instrumentation amplifier with a wide input voltage range
• Adjustable gain and offset
• Two and three-wire operation
• Protection against reverse polarity and short-circuiting
• Output current limitation
• Integrated current source
• Adjustable integrated reference voltage source: 4.5 to 10V
• Supply voltage: 6...35V
• Wide operating temperature range: -40°C...+85°C
• Individually accessible function modules
• RoHS compliant
• Two package variants: SOP and SSOP GENERAL DESCRIPTION AM400 is a monolithically integrated measuring amplifier with a parallel current and voltage output which has been specifically developed for the processing of differential input signals. AM400 consists of various functional modules. It contains both an instrumentation amplifier input and an input for signals referenced to ground. One particular feat ure of the device is the current and voltage outputs which can be used simultaneously. The output ranges can be selected using external resistors, enabling AM400 to be configured for the analog work, for example. Integrated voltage and current sources covering a wide range of values can be used to power external components. AM400 has been designed for ideal use with external processors (such as a microprocessor, for example, for signal correction [1]). BLOCK DIAGRAM VREF IN+ IN- VOUT SET OUTAD INDAI GND VSET INDAVGAINZA OUTIA INOP IOUT RS+ RS- VCC CVREF CVSET VBG 17 5 IA 76 10 18 V I 16 19 V oltage reference OP1 AM400-0 OP2 OP3 Figure 1: Block diagram of AM400 in the 20-pole version

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 4/ 21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev. 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de ELECTRICAL SPECIFICATIONS Tamb = 25°C, VCC = 24V, VREF = 5V, IREF = 1mA (unless otherwise stated); currents flowing into the IC are negative. Parameter Symbol Conditions Min. Typ. Max. Unit Supply Voltage Range VCC 6 35 V Quiescent Current ICC Tamb = – 40...+85°C, IREF = 0mA 1.5 mA Temperature Specifications Operating Tamb –40 85 °C Storage Tst –55 125 °C Junction TJ 150 °C Voltage Reference Voltage VREF VSET not connected 4.75 5.00 5.25 V VREF VSET = GND, VCC ≥ 11V 9.5 10.0 10.5 V Trim Range VR10 4.5 VR10 V Current IREF* 0 10.0 mA VREF vs. Temperature d VREF/dT Tamb = - 40...+85°C ±90 ±140 ppm/°C Line Regulation d VREF/dV VCC = 6V...35V 30 80 ppm/V d VREF/dV VCC = 6V...35V, IREF ≈ 5mA 60 150 ppm/V Load Regulation d VREF/dI 0.05 0.10 %/mA d VREF/dI IREF ≈ 5mA 0.06 0.15 %/mA Load Capacitance CL 1.9 2.2 5.0 µF Current/Voltage Source OP3 Internal Reference VBG 1.20 1.27 1.35 V VBG vs. Temperature d VBG/dT Tamb = - 40...+85°C ±60 ±140 ppm/°C Current Source: ICV = VBG/REXT Adjustable Current Range ICV* 0 10 mA Output Voltage VCV V CC < 19V VBG VCC – 4 V VCV VCC ≥ 19V VBG 15 V Voltage Source: VCV = VBG (REXT1 + REXT2) / REXT2 Adjustable Voltage Range VCV V CC < 19V 0.4 VCC – 4 V VCV VCC ≥ 19V 0.4 15 V Output Current ICV* Source 10 mA ICV Sink –100 µA Load Capacitance CL Source mode 0 1 10 nF Instrumentation Amplifier Internal Gain GIA 4.9 5 5.1 Differential Input Voltage Range VIN 0 ±400 mV Common Mode Input Range CMIR V CC < 9V, ICV < 2mA 1.5 VCC – 3 V CMIR VCC ≥ 9V, ICV < 2mA 1.5 6.0 V Common Mode Rejection Ratio CMRR 80 90 dB Power Supply Rejection Ratio PSRR 80 90 dB Offset Voltage VOS ±1.5 ±6 mV

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 5/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de Parameter Symbol Conditions Min. Typ. Max. Unit Instrumentation Amplifier (cont.) VOS vs. Temperature d VOS/dT ±5 µV/°C Input Bias Current IB –100 –250 nA IB vs. Temperature d IB/dT –0.4 –0.9 nA/°C Output Voltage Range VOUTIA VCC < 9V, RLIA ≤ 10kΩ 0* VCC – 4 V VOUTIA VCC ≥ 9V, RLIA ≤ 10kΩ 0* 5 V Minimum Output Voltage VOUTIAmin Without external load resistance RLIA 4.5 16 mV Load Capacitance CL** 250 pF Zero Adjust Stage Internal Gain GZA 0,94 1 1,06 Input Voltage VZA VZA ≤ VOUTIA - GIA VIN 0 VOUTIA V Offset Voltage VOS ±0.5 ±2.0 mV VOS vs. Temperature d VOS/dT ±1.6 ±5 µV/°C Input Bias Current IB 47 120 nA IB vs. Temperature d IB/dT 18 30 pA/°C Operational Amplifier Gain Stage (OP1) Adjustable Gain GGAIN 1 Input Range IR V CC < 10V 0 VCC – 5 V IR VCC ≥ 10V 0 5 V Power Supply Rejection Ratio PSRR 80 90 dB Offset Voltage VOS ±0.5 ±2 mV VOS vs. Temperature d VOS/dT ±3 ±7 µV/°C Input Bias Current IB 10 25 nA IB vs. Temperature d IB/dT 7 20 pA/°C Output Voltage Limitation VLIM VREF V Output Voltage Range VOUTAD VCC < 10V 0 VCC – 5 V VOUTAD VCC ≥ 10V 0 VREF V Load Capacitance CL 250 pF Operational Amplifier Output Stage (OP2) Internal Gain GOP 2.15 2.20 2.25 Input Range IR V CC < 11V 0 VCC – 5 V IR VCC ≥ 11V 0 6 V Power Supply Rejection Ratio PSRR 80 90 dB Offset Voltage VOS ±0.5 ±2 mV VOS vs. Temperature d VOS/dT ±3 ±7 µV/°C Input Bias Current IB 10 25 nA IB vs. Temperature d IB/dT 7 20 pA/°C Output Voltage Range VOUT VCC < 19V 0 VCC – 5 V VOUT VCC ≥ 19V 0 14 V Output Current Limitation ILIM VOUT ≥ 10V 5 7 10 mA Output Current IOUT 0 ILIM mA Load Resistance RL 2 kΩ Load Capacitance CL 500 nF

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 6/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de Parameter Symbol Conditions Min. Typ. Max. Unit V/I Converter Internal Gain GVI 0,120 0.125 0,130 Trim Range Adjustable by R0 0.75 1.00 1.25 Voltage Range at R0 FS VR0FS 350 750 mV Offset Voltage VOS βF ≥ 100 ±2 ±4 mV VOS vs. Temperature d VOS/dT βF ≥ 100 ±7 ±14 µV/°C Input Resistance RIN 120 160 kΩ RIN vs. Temperature d RIN/dT 0.2 0.3 kΩ/°C Output Offset Current IOUTOS 3-wire operation –25 –35 µA IOUTOS vs. Temperature d IOUTOS/dT 3-wire operation 16 26 nA/°C Output Offset Current IOUTOS 2-wire operation 9.5 14 µA IOUTOS vs. Temperature d IOUTOS/dT 2-wire operation 6 8 nA/°C Output Control Current IOUTC 2-wire operation, VR0/100mV 6 8 µA IOUTC vs. Temperature d IOUTC/dT 2-wire operation –10 –15 nA/°C Output Voltage Range VOUT V OUT = RL IOUT, VCC < 18V 0 VCC – 6 V VOUT VOUT = RL IOUT, VCC ≥ 18V 0 12 V Output Current Range FS IOUTFS IOUT = VR0/R0, 3-wire operation 20 mA Output Resistance ROUT 0.5 1.0 MΩ Load Capacitance CL 0 500 nF SET Stage Internal Gain GSET 0.5 Input Voltage VSET 0 1.15 V Offset Voltage VOS ±0.5 ±1.5 mV VOS vs. Temperature d VOS/dT ±1.6 ±5 µV/°C Input Bias Current IB 8 20 nA IB vs. Temperature d IB/dT 7 18 pA/°C Protection Functions Voltage Limitation at R0 VLIMR0 VR0 = VIN GI, SET = GND Only if OP2 and V/I-Converter are connected VREF/8 mV VLIMR0 VIN = 0, VR0 = VSET/2 580 635 690 mV Protection against reverse polarity Ground vs. VS vs. VOUT 35 V Ground vs. VS vs. IOUT 35 V Current in case of reverse polarity Ground = 35V, VS = IOUT = 0 4.5 mA System Parameters Nonlinearity Ideal input 0.05 0.15 %FS * In 2-wire operation a maximum current of IOUTmin – ICC is valid Only available in die form or in an SSOP 20 version * Depending on external load resistance at output IA (RLIA ≤ 10kΩ ⇒ VOUTIA < 3mV); internal load resistance is ≈ 100kΩ

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 7/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de BOUNDARY CONDITIONS Parameter Symbol Conditions Min. Typ. Max. Unit Sense Resistor R0 IOUTFS = 20mA 17 27 38 Ω R0 c = 20mA/IOUTFS c ⋅ 17 c ⋅ 27 c ⋅ 38 Ω Stabilization Resistor R5 IOUTFS = 20mA 35 40 45 Ω R5 c = 20mA/IOUTFS c ⋅ 35 c ⋅ 40 c ⋅ 45 Ω Load Resistance RL Limitation only for 3-wire operation 0 600 Ω Sum Gain Resistors R1 + R2 20 200 kΩ Sum Offset Resistors R3 + R4 20 200 kΩ VREF Capacitance C1 Min. value for Tamb 85°C 1.9 2.2 5.0 µF Output Capacitance C2 Only for 2-wire operation 90 100 250 nF D1 Breakdown Voltage VBR 35 50 V T1 Forward Current Gain βF BCX54/55/56, for example 50 150 DETAILED DESCRIPTION OF FUNCTIONS AM462 is a modular, monolithically integrated universal amplifier which has been specifically developed for the conditioning of differential voltage signals and those referenced to ground. It is designed for both 2- and 3-wire operation 1 in industrial applications (cf. applications on pages 14 until 19). AM462’s various functions are depicted in the block diagram (F igure 1) which also illustrates how few external components are required for the operation of this particular device. AM400 consists of a number of modular functional blocks which through external gating can either operate together or separately (see Figure 2). 1. The instrumentation amplifier (IA) with an internal gain of G IA = 5 acts as an input stage for differential voltage signals. Its special constr uction permits a high comm on mode rejection ratio (CMRR). The amplifier reference potentia l is set externally using the AM400 pin ZA. Output voltage VOUTIA at pin OUTIA is calculated for VZA > 0 as: ZAINIAOUTIA VVGV += with 0>OUTIAV (1) where VIN is the differential voltage between inputs pin IN+ and pin IN- of the IA and VZA is the voltage at pin ZA. 2. The ensuing operational amplifier stage (OP1) permits the IA output signal to be amplified further. OP1’s gain of GGAIN can be set using external resistors R 1 and R2. Protection against overvoltage has been integrated in to the device; this protective circ uitry limits the voltage to the set reference voltage value (cf. paragraph 5 in this section). 1 The principle of design is such that only the current output can be used in 2-wire operation.

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 8/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de Output voltage VOUTAD at pin OUTAD is calculated as: GAININOPOUTAD GVV ⋅= with   += 1 R RGGAIN ( 2 ) where VINOP is the voltage at the OP1 input pin INOP. Alternatively, the OP1 input pin INOP can also be used as an input for signals referenced to ground (see Application 2, Figure 6). 3. The IC’s voltage output VOUT is realized via the current-limited operational amplifier stage (OP2) which has integrated protection against revers e polarity. The internal gain of OP2 is set to a fixed value of GOP = 2.2. The output is engineered as a driver stage. The following applies to OP2’s output voltage VOUT at the IC pin VOUT: INDAVOPOUT VGV ⋅= (3) where VINDAV is the voltage at pin INDAV (OP2 input). VBG 17 5 IA 76 10 18 V I 16 19 V oltage reference OP1 Ground VS IOUT AM400-0 VREF OP2 OP3 VOUT VZA VINOP VSET VOUTAD VIN+ VIN- VCVREF VCVSET VOUTIA R3 R4 VINDAI VINDAV Figure 2: Block diagram of AM400 showing external components (3-wire circuit with a current output)

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 9/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de 4. The voltage-to-current converter (V/I converter) provides a voltage -controlled current signal at IC output IOUT which activates an external transistor T1; this reduces the pow er dissipation of the IC and supplies the output current IOUT. The external transistor is protected against reverse polarity by an additional diode D1. Via pin SET an offset current ISET can be set at output IOUT (with the help of the internal voltage referen ce and an external voltage divider as shown in Figure 5, for example). External resistor R0 permits the output current to be finely adjusted with parallel operation of current and the voltage output. For the output current IOUT boosted by T1 the following ratio applies: SET INDAI OUT IR VI += 08 with 02R VI SET SET = (4) with VINDAI the voltage at pin INDAI and VSET the voltage at pin SET (V/I converter inputs, see Figure1)2. 5. The AM400 reference voltage source enables voltage to be suppl ied to external components (such as sensors, microprocessors, etc.). The reference voltage value VREF can be set via pin VSET. If pin VSET is not connected, VREF = 5V; if VSET is switched to ground, VREF = 10V. Values between the above can be set if two exte rnal resistors are used (inserted between pin VREF and pin VSET and between pin VSET and GND). External capacitor C1 stabilizes the reference voltage. It must be connected even if the voltage reference is not in use. It also must not exceed the minimum value. 6. The additional operational amplifier (OP3) can be used as a current or voltage source for the supply of external components. OP3’s positive input is connected in ternally to voltage VBG so that the output current or voltage can be set across a wide range using one or two external resistors. 2 The construction of the V/I converter is such that output current IOUT is largely independent of the current amplification βF of external transistor T1. Production-specific variations in the current amplification of the transistors used are compensated for internally by the V/I converter.

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 10/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de OPERATING AM400 General information on 2- and 3-wire applications In 3-wire operation (cf. Figure 5, fo r example) the ground of the IC (pin GND) is connected up to the external mass of the system Ground. The system's supply voltage VS is connected to pin VCC and pin VCC to pin RS+. In 2-wire operation (cf. Figure 7) system supply voltage VS is connected to pin RS+ and pin VCC to RS-. The ground of the IC (pin GND) is connected to the node between resistor R5 and load resistor RL (current output IOUT). IC ground (GND) is not the same as system ground (Ground)!! The output signal is picked up via load resistor RL which connects current output IOUT to the system ground. In 2-wire operation the IC ground is "virtual" (floating), as with a constant load resistance the supply voltage of the device VCC changes according to the current. As a rule, the following equation applies to 2-wire operation: () LINOUTSCC RVIVV −= (5) The reason for this is that in 2-wire operation the IC is connected in series to the actual load resistor RL. This is illustrated in Figure 3. In 3-wire operation Equation 5 no longer applies as the IC ground is connected to the ground of the system. For 3-wire operation the supply voltage can be expressed thus: SCC VV = (6) In a 2-wire setup the power consumption of the overall system (AM400 and all external components including the adjusting resistors) may not exceed IOUTmin (usually 4mA). RL VS 2-wire system Signal source and conditioning IC GND Ground ≠ VCC ≠ VS Gr ound RL 3-wire system Signal source and conditioning IC GND Ground = VCC = VS Ground GND = GND VCC IOUT IOUT VVCC S = Figure 3: The difference between 2- and 3-wire operation

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 11/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de Setting the voltage gain using the voltage output When using the IA and amplifier stages OP1 a nd OP2 for further signal conditioning the overall gain can be set using the suitabl y selected external resistors R1 and R2. The transfer function for the output voltage is calculated by multiplying Equations 1, 2 and 3 to: () OPGAINZAINIAOUT GGVVGV ⋅⋅+= (7) with GIA = 5, GGAIN = (R1 /R2) + 1 and GOP = 2.2 and the externally set voltage VZA at pin ZA. Setting the output current range and compensating for the offset using the current output When using the IA together with amplifier stag e OP1 and the V/I convert er for further signal conditioning the offset of the output current should first be compensated for. To this end the two IA inputs must be short-circuited (V IN = 0) and connected up to a permitted potential (cf. CMIR in the electrical specifications on page 5). With the short circuit at the input the values of the output current according to Equation 4 and an external voltage divider (e.g. Figure 5) are as follows: () SETINOUT IVI == 0 with 02 RR R R VI REF SET +⋅= (8) The output current range is set in conjuncti on with the selected external resistors R1 and R2 (or fine adjustment with R0 ). Using Equations 2, 4 and 8 the following is calculated for output current IOUT : SET I INOUT IR GVI += 08 with GAINIAI GGG ⋅= and 0=ZAV (9) Selecting the supply voltage System supply voltage VS needed to operate AM400 is dependent on the selected mode of operation.

• When using voltage output pin VOUT the minimum supply voltage VS necessary for the operation of the device depends on the maximum output voltage VOUTmax required by the application. The following applies: V5max +≥ OUTS VV (10)
• When using current output pin IOUT (in conjunction with the external transistor) the value of VS is dependent on that of th e relevant load resistor RL (max. 600 Ω) used by the application. The minimum system supply voltage VS is then: minmax CCLOUTS VRIV +≥ (11)

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 12/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de Here, IOUTmax stands for the maximum output current and VCCmin for the minimum IC supply voltage which is dependent on the selected reference voltage: V1min +≥ REFCC VV (12) The working range resulting from Equation 11 is described in Figure 4. Example calculations and typical values for the external components can be found in the example applications. POINTS TO NOTE: INITIAL OPERATION OF AM400 1. When operating AM400 it is imperative that external capacitance C1 (a high-grade ceramic capacitor) is always connected (cf. Figure 2). Care must be taken that the value of the capacitance does not lie beyond its given range, even across th e range of temperature (see Boundary Conditions on page 7). In 2-wire operation ceramic capacitor C2 must also be used. 2. All of the AM400 function blocks not used by the a pplication (e.g. OP3) must be connected up to a defined (and permitted) potential. 3. The voltages at the IA inputs (pins IN+ and IN–) must always lie within input voltage range CMIR, even if the IA is not used. 4. When the voltage output is in operation the load resistance at pin VOUT must be at least 2kΩ. 5. A load resistance of 600Ω maximum is permitted with operation of the current output. 6. The values of external resistors R0, R1, R2, R3, R4 and R5 must be selected within the permissible range given in the boundary conditions on page 7. VS [V] RL [Ω] 6 35 VCCmin = 6V RLm ax = 600Ω IOUTmax = 20mA R VV IL S CCmin OUTmax ≤ − 2412 600 Working range 300 Figure 4: Working range in conjunction with the load resistor

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 14/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de According to Equation 4 the following is then relevant to output current IOUT: SET I INOUT IR GVI += 08 with 0=ZAV (15) with   +== 115 R RGGG GAINIAI and 02 RR R R VI REF SET +⋅= . For a measuring bridge with a signal of VIN = 0...100mV at the IA input the external components are to be dimensioned in such a way that the output current has a range of 4...20mA and the output voltage one of 0...10V. R 1 and R2 are dimensioned in accordance with Equation 14, R0 according to Equation 4 and R3 and R4 according to Equation 8. Observing the boundary conditions for the external components the following values are then obtained: R0 ≈ 35.5Ω R1 ≈ 80.9kΩ R 2 = 10kΩ R3 = 83kΩ R 4 = 5kΩ R5 = 39Ω RL = 0...600Ω RIAL ≤ 10kΩ C1 = 2.2µF 2) Typical 3-wire application with an input signal referenced to ground Ground VS IOUT VOUT R3 R4C1 RL VIN Input voltage referenced to ground Connections setting unused function blocks to a defined operating point 3-wire connection VBG 17 5 IA 76 10 18 V I 16 19 V oltage reference OP1 AM400-0 OP2 OP3 Figure 6: Typical application for input signals referenced to ground

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 16/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de where   +== 115 R RGGG GAINIAI and 02 RR R R VI REF SET +⋅= For a measuring bridge with a signal of VIN = 0...100mV at the IA input the external components of the AM400 circuitry are to be dime nsioned in such a way that th e output current has a range of 4...20mA. As only the current output is to be used, the gain and output current range can be dimensioned using resistors R1 to R4. Up to a certain point the value of resistor R0 is freely selectable and can be set to 27Ω. Observing the boundary conditions for the exte rnal components the following values are then obtained: R0 = 27Ω R1 ≈ 59.12kΩ R 2 = 10kΩ R3 = 82kΩ R 4 = 5kΩ R5 = 39Ω RL = 0...600Ω RIAL ≤ 10kΩ C1 = 2.2µF C2 = 100nF In this specific application particular attention must be paid to the current consumption which at a temperature of 85°C may not exceed 4mA. Negative offset voltages can be compensated for using pin ZA. If the pin is not in use it be connected to IC ground GND. must Ground VS IOUT R2RIAL R3 R4 RL RSET 2-wire connection IC ground: GND System ground: Ground}Different potentials! GND VBG 17 5 IA 76 10 18 V I 16 19 V oltage reference OP1 AM400-0 OP2 OP3 Figure 7: Typical 2-wire application for differential input signals

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 18/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de BLOCK DIAGRAM, 20-POLE PINOUT AND DICE PIN NAME EXPLANATION

1 CVREF Current/Voltage reference

2 CVSET Current/Voltage reference set

3 IN+ Positive input IA

4 IN– Negative input IA

5 OUTIA Output IA

6 INOP Positive amplification OP input

7 GAIN Gain set

8 OUTAD System gain output

9 INDAI Current output stage input

10 INDAV Voltage output stage input

11 IOUT Current output

12 RS– Sensor resistor –

13 VCC Supply voltage

14 RS+ Sensor resistor +

15 VOUT Voltage output

16 VSET Set reference voltage source

17 ZA Zero adjustment (offset)

18 GND IC ground

19 VREF Reference voltage source output

20 SET Output offset current set

Table 1: Pinout of the 20-pole version of AM400 VREF IN+ IN- VOUT SET OUTAD INDAI GND VSET INDAVGAINZA OUTIA INOP IOUT RS+ RS- VCC CVREF CVSET VBG 17 5 IA 76 10 18 V I 16 19 V oltage reference OP1 AM400-0 OP2 OP3 Figure 9: Block diagram of AM400 in the 20-pole version 1 20 2 19 31 8 4 17 5 16 61 5 7 14 81 3 9 12 10 11 CVREF CVSET IN+ IN- OUTIA INOP GAIN OUTAD INDAI INDAV SET VREF GND ZA VSET VOUT RS+ VCC RS- IOUT Figure 10: Pinout of the 20-pole version of AM400

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 19/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de BLOCK DIAGRAM AND 16-POLE PINOUT VREF IN+ IN- VOUT SET OUTAD INDA GNDZA GAIN VBG 13 5 14 IOUT RS+ RS- VCC V I 5V Reference IA AM400-1 CVREF CVSET OP1 OP2 OP3 Figure 11: Block diagram of AM400 in the 16-pole version PIN NAME EXPLANATION

5 GAIN Gain set

6 OUTAD System gain output

7 INDA Output stage input

8 IOUT Current output

9 RS– Sensor resistor –

10 VCC Supply voltage

11 RS+ Sensor resistor +

12 VOUT Voltage output

13 ZA Zero adjustment (offset)

14 GND IC ground

15 VREF Reference voltage source output

16 SET Output offset current set

Table 2: Pinout of the 16-pole version of AM400 1 16 2 15 3 14 4 13 5 12 6 11 7 10 CVREF CVSET IN+ IN- GAIN OUTAD INDA IOUT SET VREF GND ZA VOUT RS+ VCC RS- Figure 12: Pinout of the 16-pole version of AM400

analog microelectronics October 2005 Analog Microelectronics GmbH Phone: +49 (0)6131/91 073 – 0 21/21 An der Fahrt 13, D – 55124 Mainz Fax: +49 (0)6131/91 073 – 30 Rev.: 4.2 Internet: http://www.analogmicro.de Email: info@analogmicro .de DELIVERY The AM400 sensor transmitter is available as the following packages:

• SSOP20
• SO16(n)
• Dice on 5" blue foil (on request) PACKAGE DIMENSIONS Please see our website (data sheets: package.pdf). FURTHER READING [1] The Frame ASIC concept: http://www.Frame-ASIC.de/ [2] The Analog Microelectronics GmbH website: http://www.analogmicro.de/ Analog Microelectronics reserves the right to make amendments to any dimensions, technical data or other information contained herein without further notice.