TE6650HN Datasheet, PDF (4/6 Pages) MORNSUN Science& Technology Ltd. – Two-terminal isolation

Isolated Transmitter
TExxxxHN Series
4) Typical application of the product with ISO power output（Need to customize product with ISO power output）
Typical application ——Isolated transmission for electrical signals
Typical application of isolated transmission for electrical signals is as below.
I1
I3
I2
Fig. 5 Isolated transmission for electrical signals application
Function
In the figure 5, Signal in is detected electrical signals, Signal out is electrical signals for control system of isolation transmission. VCC is
isolated power supply provided from control system. Typical power signal is positive and negative sine wave signal. 431 R1 R2 and R3 is
voltage stabilizing circuit in the circuit, and they can achieve zero adjustment of the input signal. Amplifier of TExxxxHN series achieve signal
transmission function and power supply function of voltage stabilizing circuit. R4,R5,C1 achieve DC output signal filtering functions.
Working principle
Supposing detected signal is ±2.5V sine wave signal. When the input signal is passed through stabilizing circuit which is composed of
431,R1,R2 and R3, input signal of TExxxxHN transmitter become 0~5V sine wave signal. If the amplifier is the one which has 0~5V input and
0~5V output, TExxxxHN transmitter output would be output 0~5V sine wave signal at this time. After passed through filter circuit which is
composed of R4,R5 and C1, the DC component of 0~5V sine wave signal is filtered, and the output only have ±2.5V sine wave signal.
Parameter
In the application, typical values of R2 and R3 are 10KΩ, and reference Voltage of 431 is 1.24V. Component regulated voltage is 2.5V
(by paralleling resistance to R2 or R3). Voltage accuracy can achieve a variety of application requirements of high precision according to
the resistance tolerance precision. Value of R1 based on Pout and voltage stabilizing circuit, needs to insure the current through 431 (I2)
greater than the minimum cathode current for regulation of selected 431, the current through R1 (I1) less than the maximum output current
of TExxxxHN (5mA),typical value of R1 can selected by formula ^{Pout  2.5V} .Typical application range of R4 is 2KΩ~5KΩ. Because signal
0.002 A
output voltage is positive and negative, there will be a transmitter output signal current return-irrigation phenomenon when the voltage
signal output is negative.R4 should choose a smaller value in order to reduce the influence of the return-irrigation current. C1 should be
chosen low internal resistance capacitance. Normally ceramic capacitor with volume more than 10uF will be suitable. Because C1
achieves the function of getting through AC and preventing DC. Large capacitance resistance and small
capacitance value can
make AC signal distorted. The recommended value of R5 should be more than 100KΩ, and implements a DC signal to zero in the circuit.
The increase of value of R5 can make the time of DC signal to zero longer, and make the startup time longer. If load in circuit is too small,
then the load for AC will be increased, so that AC signal will be distorted.
Notice
Because the transmitter of TExxxxHN series can not input negative voltage signal, it need to pay attention to narrow signal voltage
amplitude and have the necessary margin in the design. It can guarantee the normal work of the circuit and reduce the risk of signal
distortion.
2016.03.24-A/0
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