VOLTAGE TRANSMITTER IC AM411 FEATURES GENERAL DESCRIPTION • Wide Supply Voltage Range: 6...35V • Wide Operating Temperature Range: –40°C...+85°C • Voltage Reference: 5V • Instrumentation Amplifier Input (Reversible Polarity) • Operational Amplifier Input • Adjustable Gain and Offset • Adjustable Output Voltage Range: 0.5...4.5V, 0...5/10V, other • Protection Against Reverse Polarity • Output Current Limitation The AM411 is a monolithic voltage transmitter, designed for flexible bridge input signal conditioning. The integrated circuit is ideally suited for a wide variety of transducers with an differential output signal. It contains a high accuracy instrumentation amplifier for differential input signals, an operational amplifier output stage, and a 5V reference. Output range and gain are adjustable by external resistors. Using the internal instrumentation amplifier the AM411 is a standard sensor transmitter with the possibility to indicate an over range signal. With the internal connected operational amplifier input this IC can be used as an adjustable voltage–to– voltage transmitter. APPLICATIONS • Industrial Process Control • Sensor Transmitter (e.g. pressure) • Programmable Voltage Source DELIVERY • DIL8 packages (samples) • SOP8 packages • Dice on 5“ blue foil BLOCK DIAGRAM ZA VREF 8 6 AM411 5 Reference Voltage VCC 1 IN+ IN− IA Output Stage 2 3 4 VOUT 7 GAIN GND Figure 1 analog microelectronics Analog Microelectronics GmbH An der Fahrt 13, D – 55124 Mainz Internet: www.analogmicro.de Phone: +49 (0)6131/91 073 – 0 Fax: +49 (0)6131/91 073 – 30 E–Mail: [email protected] April 99 1/6 Rev. 2.1 VOLTAGE TRANSMITTER IC AM411 ELECTRICAL SPECIFICATIONS Tamb = 25°C, VCC = 24V, VREF = 5V, IREF = 1mA (unless otherwise noted) Parameter Symbol Voltage Range VCC Quiescent Current ICC Conditions Min. Typ. 6 Tamb = – 40...+85°C, IREF = 0mA Max. Unit 35 V 1.5 mA Temperature Specifications Operating Tamb –40 85 °C Storage Tst –55 125 °C Junction TJ Thermal Resistance Θja DIL8 plastic package 110 °C/W Θja SO8 plastic package 180 °C/W 150 °C Voltage Reference Voltage VREF 4.75 Current IREF 0.2 VREF vs. Temperature dVREF/dT Tamb = – 40...+85°C Line Regulation dVREF/dV VCC = 6V...35V dVREF/dV VCC = 6V...35V, IREF ≈ 5mA Load Regulation dVREF/dI dVREF/dI Load Capacitance IREF ≈ 5mA 5.00 5.25 V 10.0 mA ±90 ±140 ppm/°C 30 80 ppm/V ppm/V 60 150 0.05 0.10 %/mA 0.06 0.15 %/mA 5.0 µF CL 1.9 2.2 Internal Gain GIA 4.9 5 Differential Input Voltage Range VIN 0 ±400 mV Instrumentation Amplifier Common Mode Input Range 5.1 CMIR VCC < 9V 1.5 VCC – 3 V CMIR VCC ≥ 9V 1.5 6.0 V Common Mode Rejection Ratio CMRR 80 90 dB Power Supply Rejection Ratio PSRR 80 90 dB Offset Voltage VOS VOS vs. Temperature dVOS/dT Input Bias Current IB ±1.5 –120 IB vs. Temperature dIB/dT Output Voltage Range VOUTIA VCC < 9V, VOUTIA = GIA VIN + VZA 0.02 VOUTIA VCC ≥ 9V, VOUTIA = GIA VIN + VZA 0.02 Load Capacitance ±6 –0.35 CL mV µV/°C ±5 –300 nA –0.8 nA/°C VCC – 3 V 6 V 250 pF Zero Adjust Stage Internal Gain GZA 1 Input Voltage VZA Offset Voltage VOS ±0.5 VOS vs. Temperature dVOS/dT Input Bias Current IB IB vs. Temperature dIB/dT VZA ≤ VOUTIA – GIA VIN 0 VOUTIA V ±2.0 mV ±1.6 ±5 µV/°C 38 100 nA 24 75 pA/°C Voltage Output Stage Adjustable Gain GOP Input Range IR VCC < 10V 0 1 VCC – 5 V IR VCC ≥ 10V 0 5 V analog microelectronics April 99 2/6 VOLTAGE TRANSMITTER IC Parameter Symbol Conditions AM411 Min. Typ. Max. Unit ±0.5 ±2 mV µV/°C Voltage Output Stage (cont.) Power Supply Rejection Ratio PSRR Offset Voltage VOS 80 90 dB VOS vs. Temperature dVOS/dT ±3 ±7 Input Bias Current IB 5 12 nA IB vs. Temperature dIB/dT 3.5 10 pA/°C Output Voltage Range VOUT VCC < 18V 0 VCC – 5 V VOUT VCC ≥ 18V 0 13 V Output Current Limitation ILIM VOUT ≥ 10V 5 10 mA Output Current IOUT 0 ILIM mA Load Resistance RL 2 Load Capacitance CL 7 kΩ 500 nF 35 V 0.05 0.15 %FS Typ. Max. Unit 200 kΩ 5.0 µF Protection Functions Protection against reverse polarity Ground vs. VS vs. VOUT System Parameters Nonlinearity ideal input Currents flowing into the IC are negative BOUNDARY CONDITIONS Parameter Symbol Sum Offset Resistors R3 + R4 20 C1 1.9 VREF Capacitance Conditions Min. 2.2 FUNCTIONAL DIAGRAM Reference Voltage VS RA VIN RIN AMP VOUT RB Ground Figure 2 analog microelectronics April 99 3/6 VOLTAGE TRANSMITTER IC AM411 FUNCTIONAL DESCRIPTION The IC AM411 is an integrated voltage transmitter for bridge input signals. With variations of a few external components the output voltage can be adjusted over a wide range. In addition to the resistors R1 and R2 the circuitry needs only one external capacitor C1 for a basic application. Using the input of the voltage output stage the AM411 can be used for single ended input signals as well. Typical values for the external components are listed in the Application Notes. Basically the AM411 consists of 3 functional blocks as they are shown in Figure 1: 1. A high accuracy instrumentation amplifier with an internal gain GIA and the possibility to adjust the bias voltage (pin ZA) for differential input signals. 2. An operational amplifier output stage used for voltage transmission and as the voltage output. The output stage has an output current limitation protecting the IC. 3. A voltage reference can be used as an excitation for constant voltage sensors or as supply for other external devices. The transfer function for the output voltage of the instrumentation amplifier is: VOUTIA = G IAVIN + VZA with the offset voltage VZA which can be adjusted on pin ZA. For die entire output voltage VOUT of the IC is valid VOUT = GOP ⋅ VINOP with the adjustable gain GOP GOP = R1 +1 R2 The minimum supply voltage, which has to be adjusted, can be calculated over VS ≥ VOUTmax + 5V analog microelectronics April 99 4/6 VOLTAGE TRANSMITTER IC AM411 PINOUT PIN 1 8 VREF IN− 2 7 GND GAIN 3 6 ZA VOUT 4 5 VCC IN+ Figure 3 NAME DESIGNATION 1 IN+ Non Inverting Bridge Input 2 IN– Inverting Bridge Input 3 GAIN Gain Adjustment 4 VOUT Voltage Output 5 VCC Supply Voltage 6 ZA Zero Adjust 7 GND IC Ground 8 VREF Reference Voltage DELIVERY The AM411 is available in version: • DIL8 packages (samples) • SOP8 packages • Dice on 5“ blue foil PACKAGE DIMENSIONS SOP8 4,98 ± 0,1 4,0 + 0,2 - 0,1 1,45 ± 0,1 ≤ 2,00 0,2 ± 0,05 0,2 ± 0,1 ≤ 0,635 1,27 0,42 ± 0,07 ≥ 0,3 0°-10° 6,2 ± 0,2 8 1 4 Figure 4 analog microelectronics April 99 5/6 VOLTAGE TRANSMITTER IC AM411 TYPICAL APPLICATION C1 8 AM411 Reference Voltage 5 VS 4 VOUT 1 IA Output Stage 2 R1 7 6 3 R2 Ground Figure 5 For Applications with an output signal of 0...5/10V zero adjust pin ZA has to be connected to IC Ground GND (Figure 5). The Gain G is adjusted by external resistors R1 and R2 and can be calculated by G = G IA GOP The transfer function of the output voltage VOUT becomes VOUT = G VIN With this equations the external resistors R1 and R2 can be adjusted V R1 = OUT −1 R2 GIA VIN Example 1: Output voltage range 0...10V In this case the values of the external devices ( VIN = 0K50 mV , R1 R2 = 39 ) are as follows R1 ≈ 39kΩ R2 ≈ 1kΩ GIA = 5 C1 = 2.2µF Example 2: Output voltage range 0...5V In this case the values of the external devices (VIN = 0K100mV , R1 R2 = 9 ) are as follows R1 ≈ 90kΩ R2 ≈ 10kΩ GIA = 5 C1 = 2.2µF The information provided herein is believed to be reliable; however, Analog Microelectronics assumes no responsibility for inaccuracies or omissions. Analog Microelectronics assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user's own risk. Prices and specifications are subject to change without notice. No patent rights or licences to any of the circuits described herein are implied or granted to any third party. Analog Microelectronics does not authorise or warrant any Analog Microelectronics product use in life support devices and/or systems. analog microelectronics April 99 6/6