Industrial Converter and Protector IC AM460 PRINCIPLE FUNCTION Amplification and conversion of voltage signals referenced to ground Integrated protection for IC and external components Integrated, adjustable current/voltage sources for external components VS = 6...35V Single-ended input signal IOUT = 0/4...20mA AM460 VOUT = 0...5/10V e.g. 0...5V, 0...1V VREF = 5/10V IS = e.g. 1.
Industrial Converter and Protector IC AM460 TABLE OF CONTENTS Features General Description Block Diagram Electrical Specifications Boundary Conditions Detailed Description of Functions Operating AM460 General information on 2- and 3-wire applications and the use of the current output Setting the voltage gain using the voltage output Setting the output current range using the current output Selecting the supply voltage Connecting OP2 as a current source Connecting OP2 as a voltage reference Operating AM460
Industrial Converter and Protector IC AM460 FEATURES GENERAL DESCRIPTION • Supply voltage: 6...35V • Wide working temperature range: –40°C...+85°C • Adjustable integrated reference voltage source: 4.5 to 10V • Additional voltage/current source • Operational amplifier with integrated driver stage • Adjustable amplification • Analogue parallel voltage (0...5/10V) and current output (0/4...
Industrial Converter and Protector IC AM460 ELECTRICAL SPECIFICATIONS Tamb = 25°C, VCC = 24V, VREF = 5V, IREF = 1mA (unless otherwise stated), currents flowing into the IC are negative Parameter Symbol Supply Voltage Range VCC Quiescent Current ICC Conditions Min. Typ. 6 Tamb = – 40...+85°C, IREF = 0mA Max. Unit 35 V 1.
Industrial Converter and Protector IC Parameter Symbol Conditions AM460 Min. Typ. Max. Unit 10 25 nA 7 20 pA/°C Operational Amplifier Gain Stage (OP1) (cont.) Input Bias Current IB IB vs. Temperature dIB/dT Output Voltage Limit VLIM Output Voltage Range Load Capacitance VREF V VOUTAD VCC < 10V 0 VCC – 5 VOUTAD VCC ≥ 10V 0 VREF V 250 pF CL V Operational Amplifier Output Stage (OP3) Internal Gain GOP Input Range IR VCC < 11V 0 VCC – 5 V IR VCC ≥ 11V 0 6 V ±0.
Industrial Converter and Protector IC Parameter Symbol Conditions AM460 Min. Typ. Max. Unit SET Stage Internal Gain GSET Input Voltage VSET 0.5 1.15 V Offset Voltage VOS ±0.5 ±1.5 mV VOS vs. Temperature dVOS/dT ±1.6 ±5 µV/°C Input Bias Current IB 8 20 nA IB vs.
Industrial Converter and Protector IC VREF VCVREF R3 C1 AM460 R4 VS VSET 1 15 13 16 AM460 VCVSET I 2 OP2 11 R0 10 Voltage Reference 9 VBG V VINP 8 T1 D1 3 OP1 OP3 5 4 6 R1 R2 VOUTAD 7 VOUT 12 14 R5 IOUT VINDAI VINDAV Ground Figure 2: Block diagram of AM460 with external components (3-wire circuit for current output) AM460 consist of several modular function blocks (operational amplifiers, voltage-to-current converters and references) which depending on external configur
Industrial Converter and Protector IC AM460 reduce power dissipation the transistor is an external component and 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 reference and an external voltage divider as shown in Figure 2, for example). External resistor R0 permits the output current to be finely adjusted with parallel operation of current and the voltage output.
Industrial Converter and Protector IC AM460 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: VCC = VS − I OUT (VIN ) RL (4) 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.
Industrial Converter and Protector IC RL [Ω] RL ≤ VS − VCCmin IOUTmax AM460 VCCmin = 6V RLmax = 600Ω IOUTmax = 20mA 600 300 Operating range 0 0 6 12 18 24 35 VS [V] Figure 4: Working range in conjunction with the load resistor • When using current output pin IOUT (in conjunction with the external transistor) the value of VS is dependent on that of the relevant load resistor RL (max. 600Ω) used by the application.
Industrial Converter and Protector IC AM460 cuit in Figure 5 the following applies: IS = V BG 1 . 27 V = R SET R SET (12) The bridge symbol represents the component to be supplied with current (e.g. a piezoresistive sensing element or temperature sensor). Example 1: A supply current of IS = 1mA is to be set. Using Equation 12 the following value is calculated for external resistor RSET, which in turn stipulates the size of the current: R SET = V BG 1 . 27 V = = 1 .
Industrial Converter and Protector IC AM460 R6 and R7: R 6 V CVREF = − 1 ≈ 2 .6 − 1 = 1 .6 R7 V BG The following example values are produced for the resistors: R7 = 10kΩ R6 = 16kΩ OPERATING AM460: IMPORTANT POINTS TO NOTE 1. When using AM460 it is imperative that external capacitor C1 (a top-grade ceramic capacitor) is always connected (cf. Figure 2).
Industrial Converter and Protector IC AM460 3-wire connection C1 1 16 15 13 VS ISET = 0 AM460 I 2 OP2 11 R0 10 Voltage Reference 9 VBG V VINP 8 T1 D1 3 OP1 6 5 4 Single-ended input voltage 7 VOUT 12 OP3 14 R5 IOUT R1 R2 RL Connections setting unused function blocks to a defined operating point Ground Figure 7: Typical application for input signals referenced to ground Example 3: To obtain a signal of VINP = 0...
Industrial Converter and Protector IC AM460 Typical 2-wire application with an input signal referenced to ground In 2-wire operation (cf. Figure 8) system supply voltage VS is connected up to pin RS+ and pin VCC to pin RS-. The ground of the IC (pin GND) is connected to the node between resistor R5 and load resistor RL (current output IOUT).
Industrial Converter and Protector IC GGAIN = 8R0 I OUT max − I SET 16mA = 8 ⋅ 27Ω ⋅ = 3.456 1V VINP ⇒ AM460 R1 = 3.456 − 1 = 2.456 R2 Observing the boundary conditions, the following values are obtained for the external components: R1 ≈ 24.56kΩ R0 = 27Ω R2 = 10kΩ R5 = 39Ω R3 ≈ 44.3kΩ RL = 0...600Ω analog microelectronics R4 = 2kΩ C1 = 2.
Industrial Converter and Protector IC AM460 BLOCK DIAGRAM AND PINOUT VREF SET 16 15 VSET 13 CVREF 1 AM460 CVSET I 2 OP2 11 10 Voltage Reference 9 VBG V INP RS+ VCC RS- 8 IOUT 3 OP1 4 INN OP3 5 6 OUTAD 7 12 VOUT 14 INDAI INDAV GND Figure 9: Block diagram of AM460 CVREF 1 16 SET CVSET 2 15 VREF INP 3 14 GND INN 4 13 VSET OUTAD 5 12 VOUT INDAI 6 11 RS+ INDAV 7 10 VCC IOUT 8 9 RS− Figure 10: Pinout PIN NAME 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 C
Industrial Converter and Protector IC AM460 EXAMPLES OF POSSIBLE APPLICATIONS • Conditioning signals referenced to ground (protected output stage, impedance converter etc.) 6...35V 0/4...20mA VIN = 0...1, 0...5V others Protection agains short-circuiting and reverse polarity AM460 0...5/10V Figure 11: Application for input signals referenced to ground (protected output stage, impedance converter etc.) • Complex configuration as a peripheral processor IC VCVREF = 3.3V µP 6...35V VREF = 5V 0/4...
Industrial Converter and Protector IC AM460 DELIVERY The AM460 converter and protector IC is available as the following packages: • DIP16 • SO16(n) (maximum power dissipation PD = 300mW) • Dice on 5" blue foil FURTHER READING [1] The Frame ASIC concept: http://www.Frame-ASIC.de/ [2] The Analog Microelectronics GmbH website: http://www.analogmicro.
