UR8FH High Precision Operator

If the current value of UR8FH is too small, the output signal will be very small during the test, and in order to make the measured signal meet the requirements of A/D it is necessary to increase the amplification of the amplifier circuit, which increases the error of the system. Considering the above two reasons, the current value of the constant current source in this system is set at 0.5 mA. The constant current source circuit design uses the TLC2652 high-precision chopper stabilised zero operational amplifier [2] and voltage reference source TL431.

The UR8FH chopper-stabilised zero operation gives it excellent DC characteristics, out-of-phase voltage and its drift, common-mode voltage, low-frequency noise, etc. The TL431 is a three-terminal adjustable voltage reference source with good thermal stability, and its output voltage can be set in the range of 2.5V to 36V.

UR8FH in the design of constant current source, the voltage reference source TL431 so that the voltage at the ends of A and B is 2.5 V, the B point and the TLC2652 of the 3 feet of the potential is equal to the TLC2652 of the TLC2652 of the 3 feet of the 3 feet of the TLC2652 and its 2 feet of the imaginary short, that is, 3 feet of the 3 feet of the 2 feet of the potential, which is equivalent to the point of the B point of the 2 feet of the potential of the TLC2652 of the 2 feet of the potential is equivalent to the B point and the TLC2652 of the 2 feet of the potential of the B, that is, the voltage of the two sides of the R1 with the two sides of the voltage and A, B The voltage across R1 is equal to the voltage across A and B. The voltage across R1 is also 2.5V.