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Industrial V/I Converter and Protector IC AM462
PRINCIPLE FUNCTION
Conversion of input voltage referenced to ground to output current Integrated protection for IC and external components Integrated, adjustable current/voltage sources for external components
VCC = 6...35V
Single-ended input voltage 0...VCC-5V
AM462
IOUT = e.g. 0/4...20mA
VREF = 5/10V
ICC = up to 10mA
TYPICAL APPLICATIONS
* * * * * * Adjustable voltage-to-current (V/I) converter Adjustable voltage and current source (supply unit) Voltage regulator with additional functions Industrial protector and output IC for microprocessors (the Frame ASIC concept [1]) Peripheral processor IC For examples of typical applications see Example Applications
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December2006 1/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
CONTENTS
CONTENTS FEATURES GENERAL DESCRIPTION BLOCK DIAGRAM ELECTRICAL SPECIFICATIONS BOUNDARY CONDITIONS DETAILED DESCRIPTION OF FUNCTIONS INITIAL OPERATION OF AM462
General information on 2- and 3-wire applications and the use of current Setting the output current range Selecting the supply voltage Using OP2 as a current source Using OP2 as a voltage reference
2 3 3 3 4 6 6 6
6 6 6 6 6
POINTS TO NOTE: INITIAL OPERATION OF AM462 APPLICATIONS
Typical 3-wire application with an input signal referenced to ground Typical 2-wire application with an input signal referenced to ground Application for an input signal with an offset
6 6
6 6 6
BLOCK DIAGRAM AND PINOUT EXAMPLE APPLICATIONS DELIVERY PACKAGE DIMENSIONS FURTHER READING
6 6 6 6 6
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December2006 2/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
FEATURES
* Supply voltage: 6...35V * Wide working temperature range: -40C...+85C * Adjustable integrated reference voltage source: 4.5 to 10V * Additional voltage/current source * Adjustable amplification * Adjustable offset * Industrial current output (e.g. 0/4...20mA) * Protection against reverse polarity * Short-circuit protection * Output current limitation * Low-cost device: replaces a number of discrete elements * 2- and 3-wire operation * Individually configurable function modules * RoHS compilant
GENERAL DESCRIPTION
AM462 is a universal V/I converter and amplifier IC with a number of additional functions. The IC basically consists of an amplifier, whose gain can be set externally, and an output stage which can convert voltage signals referenced to ground to industrial current signals. An additional reference voltage source for the supply of external components is also included in the device. A further operational amplifier can be connected up as a current source, voltage reference or comparator. One of the main features of the IC is its integrated protective circuitry. The device is protected against reverse polarity and has a built-in output current limit. Converter IC AM462 enables industrial current loop signals (e.g. of 0/4-20mA) to be produced relatively easily. Using the Frame ASIC concept [1] the IC can be connected up to a processor for signal correction.
BLOCK DIAGRAM
CVREF CVSET 2
AM462
OP2
VBG
1
VSET VREF SET 16 15 13
I
Voltage Reference
11 10 9
RS+ VCC RSIOUT
INP 3
V OP1
4 INN 5 OUTAD 6 INDAI 14
8
GND
Figure 1: Block diagram of AM462 (individually configurable function modules)
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December2006 3/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
ELECTRICAL SPECIFICATIONS
Tamb = 25C, VCC = 24V, VREF = 5V, IREF = 1mA (unless otherwise stated); currents flowing into the IC are negative.
Parameter Supply Voltage Range Quiescent Current Temperature Specifications Operating Storage Junction Thermal Resistance Tamb Tst TJ ja ja Voltage Reference Voltage Trim Range Current VREF vs. Temperature Line Regulation Load Regulation Load Capacitance Current/Voltage Source OP2 Internal Reference VBG vs. Temperature Current Source: ICV = VBG/RSET, from Figure Adjustable Current Range Output Voltage VBG dVBG/dT Tamb = - 40...+85C 1.20 1.27 60 1.35 140 V ppm/C VREF VREF10 VREFADJ IREF* dVREF/dT dVREF/dV dVREF/dV dVREF/dI dVREF/dI CL IREF 5mA 1.9 Tamb = - 40...+85C VCC = 6V...35V VCC = 6V...35V, IREF 5mA VSET not connected VSET = GND, VCC 11V 4.75 9.5 4.5 0 90 30 60 0.05 0.06 2.2 5.00 10.0 5.25 10.5 VREF10 10.0 140 80 150 0.10 0.15 5.0 V V V mA ppm/C ppm/V ppm/V %/mA %/mA F DIL16 plastic package SO16 narrow plastic package 70 140 -40 -55 85 125 150 C C C C/W C/W Symbol VCC ICC Tamb = - 40...+85C, IREF = 0mA Conditions Min. 6 Typ. Max. 35 1.5 Unit V mA
5
ICV* VCV VCV VCC < 19V VCC 19V 0 VBG VBG 10 VCC - 4 15 mA V V
Voltage Source: VCV = VBG (1 + R7 / R6), from Figure Adjustable Voltage Range Output Current Load Capacitance Operational Amplifier Gain Stage (OP1) Adjustable Gain Input Range Power Supply Rejection Ratio Offset Voltage GGAIN IR IR PSRR VOS VCV VCV ICV* ICV CL
6
VCC < 19V VCC 19V Source Sink Source mode 0 1 VCC < 10V VCC 10V 0 0 80 90 0.5 2 VCC - 5 5 V V dB mV 1 0.4 0.4 VCC - 4 15 10 -100 10 V V mA A nF
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December2006 4/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
Parameter Symbol Conditions Min. Typ. Max. Unit Operational Amplifier Gain Stage (OP1) (cont.) VOS vs. Temperature Input Bias Current IB vs. Temperature Output Voltage Limitation Output Voltage Range Load Capacitance V/I Converter Internal Gain Trim Range Voltage Range at R0 FS Offset Voltage VOS vs. Temperature Input Resistance RIN vs. Temperature Output Offset Current IOUTOS vs. Temperature Output Offset Current IOUTOS vs. Temperature Output Control Current IOUTC vs. Temperature Output Voltage Range Output Current Range FS Output Resistance Load Capacitance SET Stage Internal Gain Input Voltage Offset Voltage VOS vs. Temperature Input Bias Current IB vs. Temperature Protection Functions Voltage Limitation at R0 Protection against reverse polarity Current in the event of reverse polarity System Parameters Nonlinearity Ideal input 0.05 0.15 %FS VLIMR0 VINDAI = 0, VR0 = GSET VSET Ground vs. VS vs. VOUT Ground vs. VS vs. IOUT Ground = 35V, VS = IOUT = 0 4.5 580 635 690 35 35 mV V V mA GSET VSET VOS dVOS/dT IB dIB/dT 0 0.5 1.6 8 7 0.5 1.15 1.5 5 20 18 V mV V/C nA pA/C VR0FS VOS dVOS/dT RIN dRIN/dT IOUTOS dIOUTOS/dT IOUTOS dIOUTOS/dT IOUTC dIOUTC/dT VOUT VOUT IOUTFS ROUT CL 3-wire operation 3-wire operation 2-wire operation 2-wire operation 2-wire operation, VR0/100mV 2-wire operation VOUT = RL IOUT, VCC < 18V VOUT = RL IOUT, VCC 18V IOUT = VR0/R0, 3-wire operation 0.5 0 0 0 20 1.0 500
F F
dVOS/dT IB dIB/dT VLIM VOUTAD VOUTAD CL GVI Adjustable by R0 100 100 120 0.2 0,12 0.75 350 VCC < 10V VCC 10V 0 0
3 10 7 VREF
7 25 20 VCC - 5 VREF 250
V/C nA pA/C V V V pF
0.125 1.00 2 7 160 0.3 -25 16 9.5 6 6 -10
0,13 1.25 750 4 14 mV mV V/C k k/C -35 26 14 8 8 -15 VCC - 6 12 A nA/C A nA/C A nA/C V V mA M nF
* In 2-wire operation a maximum current of IOUTmin - ICC is valid
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December2006 5/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
BOUNDARY CONDITIONS
Parameter Sense Resistor Stabilization Resistor Load Resistance Sum Gain Resistors Sum Offset Resistors VREF Capacitance Output Capacitance D1 Breakdown Voltage T1 Forward Current Gain Symbol R0 R R R RL R1 + R2 R3 + R4 C1 C2 VBR
F
Conditions IOUTFS = 20mA c = 20mA/IOUTFS IOUTFS = 20mA c = 20mA/IOUTFS Limitation only for 3-wire operation
Min. 17 c 17 35 c 35 0 20 20
Typ. 27 c 27 40 c 40
Max. 38 c 38 45 c 45 600 200 200
Unit
k k F nF V
Ceramic Only for 2-wire operation BCX54/55/56, for example
1.9 90 35 50
2.2 100 50 150
5.0 250
DETAILED DESCRIPTION OF FUNCTIONS
AM462 is a modular, universal V/I converter and protector IC which has been specially developed for the conditioning of voltage signals referenced to ground. It is designed for both 2- and 3-wire operation in industrial applications (cf. application in Figure 8). AM462's various functions are depicted in the block diagram (Figure 2) which also illustrates how few external components are required for the operation of this particular device. AM462 consists of several modular function blocks (operational amplifiers, voltage-to-current converters and references) which, depending on external configurations, can either be switched to one another or operated separately (see the basic circuitry in Figure 2): 1. Operational amplifier stage OP1 enables a positive voltage signal to be amplified. OP1 gain GGAIN can be set via external resistors R1 and R2. Protective circuitry against overvoltage is integrated into the chip, limiting the voltage to the set value of the reference voltage. Output voltage VOUTAD at pin OUTAD is calculated as:
VOUTAD = VINP GGAIN with GGAIN = 1 +
R1 R2
(1)
where VINP is the voltage at OP1's input pin INP. 2. The internal voltage-to-current converter (V/I converter) provides a voltage-controlled current signal at IC output IOUT (pin 8) which activates an external transistor T1; this in turn supplies the actual output current IOUT. To 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. For the output current provided by T1 the following ratio applies:
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December2006 6/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
I OUT = VINDAI V + I SET with I SET = SET 8 R0 2R 0
(2)
with VINDAI the voltage at pin INDAI and VSET the voltage at pin SET (V/I converter inputs)1.
VREF VCVREF 1 13 C1 15 R3 16 R4 VSET VS
VCVSET 2
AM462
OP2
VBG
I
Voltage Reference
11 10 9
R0
VINP 3
V OP1
4 R1 VOUTAD 5 6 VINDAI 14
8
T1 D1
R5
IOUT
R2
Ground
Figure 2: Block diagram of AM462 with external components (3-wire circuit for current output)
3. The AM462 reference voltage source enables voltage to be supplied to external components (such as sensors, microprocessors, etc.). The reference voltage value VREF can be set via pin 13 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 external resistors are used (inserted between pin VREF and pin VSET and between pin VSET and GND; see Figure 2). External (ceramic) capacitor C1 at pin VREF stabilizes the reference voltage. It must be connected even if the voltage reference is not in use. 4. The additional operational amplifier stage OP2 can be used as a current or voltage source to supply external components. OP2's positive input is connected internally to voltage VBG so that the output current or output voltage can be set across a wide range using one or two external resistors.
The construction of the V/I converter is such that output current IOUT is largely independent of the current amplification F of external transistor T1. Production-specific variations in the current amplification of the transistors used are compensated for internally by the V/I converter.
1
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December2006 7/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
INITIAL OPERATION OF AM462
General information on 2- and 3-wire applications and the use of current In 3-wire operation (cf. Figure 3 right and Figure 7) 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 3 left and 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:
VCC = VS - I OUT (VIN ) RL
(2)
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 VCC = VS, as the IC ground is connected to the ground of the system.
2-wire system signal source and conditioning IC
GND Ground VCC VS GND
VCC IOUT RL VS
3-wire system signal source and conditioning IC
GND = Ground VCC = VS
IOUT RL VCC = VS
Ground
Ground = GND
Figure 3: The difference between 2- and 3-wire operation Setting the output current range When using amplification stage OP1 together with the V/I converter for voltage-to-current conversion the offset of the output current should first be compensated for by suitable selection of resistors R3 and R4. To this end the OP1 input must be connected to ground (VINP = 0). With the short circuit at the input and by connecting up V/I converter pin VSET as shown in Figure 2 the values of the output current according to Equation 2 are as follows:
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December2006 8/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
I OUT (V INDAI = 0 ) = I SET = V REF R4 2 R 0 R3 + R 4
(3)
and thus for the ratio of the resistors R3/R4:
R3 VREF = -1 R4 2R0 I SET
(4)
The output current range is set in conjunction with the selected external resistors R1 and R2 (or fine adjustment with R0 ). Using Equations 1 and 2 the following is calculated for output current IOUT :
I OUT = VINP GGAIN R + I SET with GGAIN = 1 + 1 8 R0 R2
(5)
Selecting the supply voltage System supply voltage VS needed to operate AM462 is dependent on the selected mode of operation. 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. 600) used by the application. The minimum system supply voltage VS is then:
VS I OUT max RL + VCC min
(6)
Here, IOUTmax stands for the maximum output current and VCCmin for the minimum IC supply voltage which is dependent on the selected reference voltage:
VCC min VREF + 1V
RL [] 600 RL VS - VCCmin IOUTmax VCCmin = 6V RLmax = 600 IOUTmax = 20mA
(7)
300 Working range 0
0
6
12
18
24
35
VS [V]
Figure 4: Working range in conjunction with the load resistor
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December2006 9/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
The working range resulting from Equation 6 is described in Figure 4. Example calculations and typical values for the external components can be found in the example applications from page 13 onwards. Using OP2 as a current source The additional operational amplifier OP2 can easily be connected up as a constant current source. Using the circuit in Figure 5 the following applies:
OP2 connected as current source
IS
AM462
2
1
OP2
RSET VBG
Figure 5: Using OP2 as a constant current source Example : OP2 as courrent source
IS = V BG 1 .27 V = R SET R SET
(8)
The bridge symbol represents the component to be supplied with current (e.g. a piezoresistive sensing element or temperature sensor). A supply current of IS = 1mA is to be set. Using Equation 8 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 .27 k IS 1mA
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December2006 10/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
Using OP2 as a voltage reference In addition to the integrated voltage reference OP2 can also be used to supply voltage to external components, such as A/D converters and microprocessors, for example. Lower voltages can be generated (e.g. 3.3V) which with the increasing miniaturization of devices and need for ever lower levels of power dissipation in digital components is today of growing importance.
OP2 connected as voltage reference
VCVREF
P
R6 2 R7
AM462 OP2
VBG
1
Figure 6: Using OP2 as a voltage reference
The additional operational amplifier OP2 can easily be connected up as a voltage reference. Using the circuit in Figure 6 the following applies:
R V CVREF = V BG 1 + 6 = 1 . 27 V R7 R 1 + 6 R7
(9)
Example : OP2 as voltage reference A voltage of VCVREF = 3.3V is to be set. Using Equation 9 the following ratio is calculated for external resistors 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 = 10k R6 = 16k
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December2006 11/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
POINTS TO NOTE: INITIAL OPERATION OF AM462
1. When operating AM462 it is imperative that external capacitor C1 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 the range of temperature (see Boundary Conditions on page 7). In 2-wire operation ceramic capacitor C2 must also be used (cf. Figure 8). 2. In a 2-wire setup the power consumption of the overall system (AM462 plus all external components, including the configuration resistors) must not exceed the sum of IOUTmin (usually 4mA). 3. All AM462 function blocks not required by the application must be connected to a defined (and allowed) potential. 4. A load resistance of 600 maximum is permitted for the current output. 5. 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.
APPLICATIONS
Typical 3-wire application with an input signal referenced to ground Figure 7 shows a 3-wire application in which AM462 amplifies and converts a positive voltage signal referenced to ground. The unused blocks (e.g. OP2) have been set to defined operating points in the application. Alternatively, these function groups can also be used here (e.g. to supply external components). For output current IOUT the following applies according to Equations 1 and 2:
I OUT = VINP R GI + I SET with GI = GGAIN = 1 + 1 8 R0 R2
Example: 0...20mA Voltage-To-Current Transmitter To obtain a signal of VINP = 0...1V at the OP1 input the external components are to be dimensioned in such a way that the output current has a range of 0...20mA (i.e. ISET = 0 SET = GND). With R0 = 27:
I OUT = VINP G GI + I SET = VINP GAIN 8R0 8 R0
The following then applies to the gain:
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December2006 12/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
C1
3-wire connection
AM462
2
1
13
15
16
ISET = 0
VS
I OP2
VBG Voltage Reference
11 10 9
R0
VINP 3
V OP1
4 5 R1 6 14
8
T1 D1
Single-ended input voltage
R5
IOUT RL
R2
Connections setting unused function blocks to a defined operating point
Ground
Figure 7: Typical application for input signals referenced to ground
GGAIN = 8R0
I OUT 20mA = 8 27 4.32 VINP 1V
R1 = 4.32 - 1 = 3.32 R2
Observing the boundary conditions (page 7), the following values are obtained for the external components: R1 33.2k R2 = 10k R0 = 27 R5 = 39 RL = 0...600 C1 = 2.2F
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.. 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. It must be ensured that in 2-wire operation an additional current load (use of current/voltage source) is limited to 4mA due to the domestic current supply and limitation. For output current IOUT the following applies according to Equations 1 and 2:
I OUT = VINP R GI V R4 + I SET with GI = GGAIN = 1 + 1 and I SET = REF 8R0 R2 2R0 R3 + R4
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December2006 13/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
C1 R3 15 16 R4
VS R0 C2
AM462
2
1
13
I OP2
VBG Voltage Reference
11 10 9
VINP 3
V OP1
4 5 R1
IC ground: GND
8
T1 D1
2-wire connection
6
14
Single-ended input voltage
R5
IOUT RL
R2
System ground: Ground
}
different potentials!
GND Ground
Connections setting unused function blocks to a defined operating point
Figure 8: Typical 2-wire operation for input signals referenced to ground
Example : 4...20mA Voltage-To-Current Transmitter
To obtain a signal of VINP = 0...1V at the OP1 input the external components are to be dimensioned in such a way that the output current has a range of 4...20mA. The following applies:
I OUT = VINP G GI + I SET = VINP GAIN + 4mA 8 R0 8R0
With R0 = 27 and ISET = 4mA Equation 4 produces the following for resistors R3 and R4:
R3 VREF 5V = -1 = - 1 22.15 2 27 4mA R4 2R0 I SET and thus the following value for the gain: GGAIN = 8R0 I OUT max - I SET 16mA = 8 27 = 3.456 1V VINP R1 = 3.456 - 1 = 2.456 R2
Observing the given boundary conditions, the following values are obtained for the external components: R1 24.56k R0 = 27 R2 = 10k R5 = 39 R3 44.3k RL = 0...600 R4 = 2k C1 = 2.2F C2 = 100nF
December2006 14/20 Rev. 2.4
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Industrial V/I Converter and Protector IC AM462
Application for an input signal with an offset
It is not uncommon for input signals to have an offset (e.g. of 0.5...4.5V or 1...6V). For signals such as these an offset current is generated at the IC output also when ISET = 0. The circuit can then be dimensioned as described in the following. According to Equation 2 the following applies for a required current swing at the output of IOUT = IOUTmax - IOUTmin:
I OUT = VPIN 6 8R0
VPIN 6 = 8R0 I OUT
(10)
For an input current swing of VIN = VINmax - VINmin the necessary gain is calculated as:
G= VPIN 6 VIN
(11)
If G < 1, the input signal can be routed directly to pin 6 (INDAI) via a voltage divider without OP1 having to be used (see Figure 9). With this circuitry the following results:
G= VPIN 6 R9 = VIN R8 + R9
VIN R8 = -1 R9 VPIN 6
(12)
From input offset VINmin the following output current is then obtained when ISET = 0:
I OUT (VIN min ) = VIN min R9 1 R8 + R9 8R0
(13)
Using the SET pin and Equation 2 the required minimum output current IOUTmin can then be set:
I OUT = VIN R9 1 V R4 + I SET with I SET = REF 2R0 R3 + R4 R8 + R9 8 R0
(14)
Example : 4..20mA Voltage-To-Current Transmitter with Input Signal Offset
To obtain a signal of VIN = 0.5...4.5V the external components are to be dimensioned in such a way that the output current has a range of 4...20mA. The circuitry is shown in Figure 9. OP1 is not used here. It is, however, available to the user as an additional OP and can be used as an impedance converter at the voltage-to-current converter input INDAI, for example. With reference to Equation 10 and with R0 = 27, a voltage swing is obtained at pin 6 of: VPIN 6 = 8R0 I OUT = 8 27 16mA = 3.456V Using Equation 12 the following applies: R8 VIN - VPIN 6 4V - 3.456V = = 0.157 VPIN 6 3.456V R9 R9 = 6.35 R8
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December2006 15/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
C1 R3 15 16 R4
3-wire connection
VS
AM462
2
1
13
I OP2
VBG Voltage reference
11 10 9
R0
V OP1
4 V IN 5 R8 6 14
8
T1 D1
3
R5
IOUT RL
Single-ended input voltage
R9
Connections setting unused function blocks in a defined operating point
Ground
Figure 9: Converting an input signal with an
According to Equation 13 the minimum output current generated by the input offset is calculated as: I OUT min = VIN min R9 1 6,37 1 = 0.5V 2mA R8 + R9 8R0 6.37 + 1 8 27
To obtain an output current of IOUT = 4...20mA, according to the above a current of ISET = 2mA must then be added. With reference to Equation 4 the ratio of R3 to R4 is calculated thus:
I SET = 2mA =
!
VREF R4 2R0 R3 + R4
R3 VREF 5V = -1 = - 1 45.3 2 27 2mA R4 2R0 I SET
Observing the given boundary conditions, the following values are obtained for the external components: R0 = 27 R5 = 39 R8 10k RL = 0...600 R9 = 63.7k C1 = 2.2F R3 = 90.6k R4 = 2k
analog microelectronics
Analog Microelectronics GmbH An der Fahrt 13, D - 55124 Mainz Internet: http://www.analogmicro.de Phone: Fax: Email: +49 (0)6131/91 073 - 0 +49 (0)6131/91 073 - 30 info@analogmicro.de
December2006 16/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
BLOCK DIAGRAM AND PINOUT
CVREF CVSET 2 VSET VREF SET 16 15 13
AM462
OP2
VBG
1
I
Voltage Reference
11 10 9
RS+ VCC RSIOUT
INP 3
V OP1
4 INN 5 OUTAD 6 INDAI 14
8
GND
Figure 10: Block diagram of AM462
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
NAME CVREF CVSET INP INN OUTAD INDAI N.C. IOUT RS- VCC RS+ N.C. VSET GND VREF SET
EXPLANATION
Current/Voltage reference Current/Voltage reference set Positive input Negative input System amplification output Current output stage input Not connected Current output Sensing resistor Supply voltage Sensing resistor + Not connected Reference voltage source set IC ground Reference voltage source output Output offset current set
CVREF CVSET INP INN OUTAD INDAI N.C. IOUT
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
SET VREF GND VSET N.C. RS+ VCC RS-
Figure 11: AM462 Pin out
Table 1: AM462 Pin out
analog microelectronics
Analog Microelectronics GmbH An der Fahrt 13, D - 55124 Mainz Internet: http://www.analogmicro.de Phone: Fax: Email: +49 (0)6131/91 073 - 0 +49 (0)6131/91 073 - 30 info@analogmicro.de
December2006 17/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
EXAMPLE APPLICATIONS
*
Application as a voltage-to-current converter IC
Protection against short circuiting and reverse polarity
6...35V VIN = 0...1, 0...5V ... and other 0/4...20mA
AM462
Figure 12: Application as a current converter IC
*
Converting a 0.5...4.5V sensor (voltage) signal
Protection against short circuiting and reverse polarity
VREF = 5/10V VOUT = 0.5...4.5V
6...35V 4...20mA
Sensor
AM462
Figure 13: Converting a 0.5...4.5V sensor signal
*
Configuration as a peripheral processor IC [2]
Protection against short circuiting and reverse polarity
VCVR EF = 3.3V
VREF = 5V
6...35V 0/4...20mA
P
DAC
AM462
Figure 14: Configuration as a peripheral processor IC and supply unit
analog microelectronics
Analog Microelectronics GmbH An der Fahrt 13, D - 55124 Mainz Internet: http://www.analogmicro.de Phone: Fax: Email: +49 (0)6131/91 073 - 0 +49 (0)6131/91 073 - 30 info@analogmicro.de
December2006 18/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
*
Application as an analog output IC and supply unit for sensors
Protection against short circuiting and reverse polarity
VR EF = 5/10V
VCV REF = 3.3V
6...35V 0/4...20mA
Sensor
P
DAC
AM462
Figure 15: Output IC and supply unit in sensor applications
*
Application as a front-end and back-end IC for microprocessors
VCVREF=3.3V Protection against short circuiting and reverse polarity
VREF=5/10V
6...35V 0/4...20mA
Sensor
AM462
ADC DAC
P
Figure 16: Application as an analog front end and back end for microprocessors (Frame ASIC concept)
analog microelectronics
Analog Microelectronics GmbH An der Fahrt 13, D - 55124 Mainz Internet: http://www.analogmicro.de Phone: Fax: Email: +49 (0)6131/91 073 - 0 +49 (0)6131/91 073 - 30 info@analogmicro.de
December2006 19/20 Rev. 2.4
Industrial V/I Converter and Protector IC AM462
DELIVERY
The AM462 V/I converter and protector IC is available as the following packages:
* SSOP16 * SO16(n)
* Dice on 5" blue foil (on request)
PACKAGE DIMENSIONS
Please see our website (data sheets: package.pdf).
FURTHER READING
www.analogmicro.de [1] [2]
The Frame ASIC concept: See:
The AM462 can be used as an integrated solution to interface a microprocessor to the industrial 4...20mA network. See: Technical Articles: PR1011 and Interfacing the Processor with the 4...20mA current loop signal (PLC). See: Application notes AN1014.
NOTES
Analog Microelectronics reserves the right to make amendments to any dimensions, technical data or other information contained herein without further notice.
analog microelectronics
Analog Microelectronics GmbH An der Fahrt 13, D - 55124 Mainz Internet: http://www.analogmicro.de Phone: Fax: Email: +49 (0)6131/91 073 - 0 +49 (0)6131/91 073 - 30 info@analogmicro.de
December2006 20/20 Rev. 2.4

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