Isolation Transmitters

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Isolation Amplifier Module Power Supply Testing Isolation Amplifier Module Millivolt-class Positive and Negative Signal Amplifier The TM_CP series isolation amplifier modules have a millivolt-class positive and negative signal input and positive and negative signal output. These modules, with a high efficiency micro-power source built-in, can provide power for signal processing circuit. In the three-wire and four-wire transmitter applications, our products make customers’ design simple and helpfully improve the room-using ratio of PCB. Adopting electromagnetism isolation technology, it is available to keep higher accuracy and extremely lower temperature drift than photocoupler isolation. These modules have three-port isolation(input, output and power supply),and the isolation voltage between them is up to 2.5KVDC. PACKAGE INFORMATION AND PIN ASSIGNMENT 20.30 [0.800] 4.10 [0.161] 15.24 [0.600] ELECTRICAL CHARACTERISTICS Power Supply Parameter Input Parameter Output Parameter 31.80 [1.252] 1 3 11 12 24 23 16 15 2.54 [0.100] 27.94 [1.100] 0.50 [0.020] Note:First angle projection 14 13 9.50 [0.374] Power Supply..........(24VDC/15VDC/12VDC)±5% Power Consumption...≤1W Power Protection....Reverse protection Input Signal.......... ±10/±20/±30/±50/±75/±100mV Input Impedance....≥10MΩ(@ max input signal) Overload...............≤5V Output Signal.......... ± 5V/ ± 10V Load Capacity..........≥2K Ω(@ ±10V output) PRODUCT PROGRAM 15.24 [0.600] 2.54 [0.100] Part Number TM4530CP TM4630CP TM5530CP TM5630CP TM6530CP TM6630CP 24 23 16 15 14 1 2 3 11 2.54 [0.100] 27.94 [1.100] 1.93 [0.176] Power Supply 24V 24V 24V 24V 24V 24V ?1.00 [0.039] Note: We could also offer customer design for special input and output. 13 12 Pin 1(Sout-) 3(Sout+) 11(Sin+) 12(Sin-) 23(Pin+) 24(Pin-) Others Function Signal output(-) Signal output(+) Signal input(+) Signal input(-) Power supply(+) Power supply(-) NC NC: No connection, otherwise the module will be damaged. Unit: mm General tolerances: ± 0.25 FEATURES High precision(0.1% F.S.) High linearity(0.1% F.S.) TRANSMISSION CHARACTERISTICS Isolation voltage(2.5KVDC/60S) Low temperature drift(35ppm/℃) Industry standard(Operating temperature range: -25℃ ~ 71℃) High reliability(MTBF>500,000 hours) Zero Offset.. .............. 0.1%F.S. Gain Error..................0.1%F.S. Temperature Drift.........≥50mV: 0.0035%F.S./ ℃ < 50mV: 0.0050%F.S./℃(-25℃~+71℃) ISOLATION CHARACTERISTICS Galvanic Isolation.......Three-port isolation (Input, output and power supply ) Isolation Voltage............2.5KVDC(Tested for 1minute ,leakage current
DC-DC Converter Application Notes Isolation Amplifier Module Application Notes 9.Capacitive load To meet the requirements of capacitive loads, it is recommended for wide input series, the recommended capacitor is 100uF. 10.Output low load and overload protection 1) Low load prevention circuit Most isolated DC/DC converters have some minimum load required to guarantee proper operation and regulation. Typically, this is 10% (non-isolated series can stand continuous unload). The output voltage will increase above stated spec for unregulated, For example, when converter is supplying power to a relay, MOSFET or IC of low power consumption(such as 485), it is recommended to guarantee a 10% load under worst case conditions. As the figure shows: 2) Overload prevention circuit Though some current can be limited by a filter, when overload and/or short circuit conditions occur, a high current can cause damage to DC/DC converters. It is recommended that one installs a slow blow type fuse of rating 3 times max input current on the input as shown. Contact factory for details. As the figure shows Simple overload protection (1) Sometimes a circuit breaker can be used. (2) Sometimes we also can avoid overload by limiting the input current as the above figure shows: A: Utilize a pre-regulator to limit the input current, but the overall efficiency will be reduced. B: A series resistor network may be placed before the converter to limit current, but in all but a few cases, this is usually impractical. C: To limit input current by setting RGND, 0.7V=RGND*ILIMIT with an op amp circuit. (3) A: An opto-isolator can be used to limit PWM duty cycle. B: A thermistor can be used to measure the current and provide feedback to the PWM. 11. Special function pin explanation 1) Output voltage trimming range Through adding a resistor at the TRIM terminal, the user can adjust the output voltage ±10% around its rated value. The total output power of the converter should be limited to its maximum specified output power. Figure 1 shows how to connect the external trim resistors. If only to adjust to higher (or lower) voltage, the resistor could be connected only between TRIM terminal and negative output (or positive output). The general rules are, to increase output voltage, adding resistor between TRIM terminal and negative output is all that is needed; to decrease output voltage, then adding resistor between TRIM terminal and positive output is all that is needed. If TRIM is not needed, just leave it open circuit. Figure 1: How to connect resistors for trimming 2) Remote on/off control Remote ON/OFF control refers to the turning on or off the converter by external means. Remote on/off control pin is usually called CTL terminal, CNT terminal or REM terminal. There're two standard remote control models. Positive Logic: CTL terminal connected directly to -VIN, output OFF; CTL terminal open or connected to up level (TTL High) output ON. Negative Logic: CTL terminal connected directly to -VIN, output ON; CTL terminal open, output OFF. Input Control signal Figure 2: isolated control method LOAD Figure 3: general control method In some special applications, isolated control method is required, see figure 2 for the reference circuit. Input Control signal 1.Functions Isolation amplifier module can change the DC voltage, current signal to different isolated DC voltage or current signal at linear proportional. 1.1: On most occasions of MCU applications, transmitters are widely used to translate the signals, which can’t be measured directly by MCU, into electrical analog signal which can be processed by MCU easily. There are current transmitter, press transmitter, temperature transmitter, flow rate transmitter, etc. Typical application is as follows: Transmitter: Temperature pressure location speed flux humidity acousto-optic identification Display/Signal output DC/DC Isolation Amplifier Power Management 2.The typical applications A/D D/A Processor (eg.MCU) Logic Interface 1.2: In modern electric measurement and controlling, usually, we will use low-voltage instrument to measure and control high-voltage, heavy current and something like analog signals. If there is no isolation between the digital signal and those analog signals, the high-voltage, heavy current will easily merge into low-voltage instrument and cause terrible damage and even safety accidents.schematic diagram is as below: 1000VDC M 60mV Isolation Amplifier 0V Isolation of dangerous high voltages A Shunt 1000VDC 0V 60mV M I interfere V interfere Avoiding interference caused by differences in potential MORNSUN Isolation amplifier module pins functions as follows (Active voltage signal input models with one channel isolation power output): 24 23 22 21 20 16 15 14 13 MORNSUN TxxxxD CNXXX Isolation Amplifier 1 2 3 4 5 9 10 11 12 1 Sout- 2 Iout+ 3 Vout+ 4 NC 5 NC 9 NC 10 NC 11 Vi+ 12 Vi- 24 Vp- 23 Vp+ 22 NC 21 NC 20 NC 16 NC 15 NC 14 Viso+ 13 Viso- Remark: This pins functions were in available to DIP24/SMD24 general series, DIP16/SMD16 small size series is different from this. The actual functions are subject to technical manual. 2.1 Power supply Vp+, Vp- are the inputs pins of power supply, Vp+ is the positive electrode, while Vp- is the negative, ±5% voltage precision, if the voltage errors is too large, the Isolation amplifier module can work normally, but can’t be assured long-term stability and normal singnal drive capacity. Please pay attention to the polar of input signal during connection; Very low supply voltage will not do any damage to equipment, but the driving capacity is not well guaranteed. The supply voltage should not exceed +15% of the nominal value, or it will do damage to the instrument. We recommend connecting a power protection circuit at the input end to protect the module. 2.2 Isolation power output Viso+ & Viso- is the output pin, Viso+ is the positive output of micro isolation power output, Viso- is the negative. Our isolation power output can offer 30mA output current, suitable to the power supply of input sensor or front processing circuit. Isolation power A output can also be connected with current loop to meet the requirement of two-wire translator. The output of this isolation power output is non-regulated, if the front circuit requires regulation, then connect an external LDO or three-port regulator. If the isolation power output is not needed, then just keep it suspended. No need to connect external capacitor if there is no highly requirement of isolation power output. If want to reduce the ripple of isolation power output, the external capacitance value should be within 4.7μF, or using regulator IC to realize it. Besides, the specification of isolated output must match the power specification of instruments to avoid the damage to the field instruments. 2.3 Input signal Vi+ is the positive electrode of input signal, Vi- is the negative electrode of output signal. a: Real input measurement range is the same as assigned value of input & output signal measurement range. The connection is showed as below, Sv is voltage signal source, which can access the input signal end directly. MORNSUN TxxxxD CNXXX Isolation Amplifier b: Real input measurement range is larger than the assigned signal value. The solution is as below: Sv is voltage signal source, which can access the input signal end by driver a sampling resistance, because the input independence is very high, so the connection will not effect the module’s input signal. MORNSUN TxxxxD Vi=R1/(R1+R2)*Sv CNXXX Isolation Amplifier C: Current signal input The solution is as below: Si is current signal source, according to ohm law, the current signal will be converted into voltage signal by sampling resistance Ri, then can access the input end directly. The input voltage measurement range can be got by choosing proper sampling resistance value. It will not do any effect to the input signal because of the module’s high input independence. The sampling resistance will not be needed if it’s current signal input series which can access the input end directly. MORNSUN TxxxxD Vi=Ri*Sv 2.4 Output signal Sout-,Iout+,Vout+ are signal output Pins. Sout- is the negative output of signal, Iout+ is the positive output of constant current signal, Vout+ is the positive output of voltage signal. a: Current signal output The solution is as below, the current output is from PIN Iout+. Usually, Iout+ can offer a constant current signal and the load capacity is less than 500Ω, that is if the load is less than 500Ω, the correspondent output is only depend on the input signal, not the load. This characteristic determines that current signal is suitable to long distance transmission.Only connect a sampling resistance with constant current loop at the remote terminal, the voltage of the sampling resistance is linear proportional to input signal. Ā + Rs MORNSUN Vi CNXXX Isolation Amplifier TxxxxD Vi Sv - + CNXXX Isolation Amplifier lo=4~20mA Sv - + - Si + R1 R2 Ri 67 68
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