A low-cost but precise temperature test circuit

Published:2011/6/26 21:40:00 Author:Borg | Keyword: low-cost, precise, temperature test circuit | From:SeekIC

With 3DG6 as the temperature sensor, the test amplifier composed of the LM324 op-amp is shown in figure 1. The transistor 3DG6 is located in the test spot, and its basic pole is short with its collecting electrode, i.e the emitting positive bias, the collecting knot 0 bias is used as the temperature sensor, the power supply provides with 45mA collecting electrode current for 3DG6 with the help of resistor R1 (100K). Its UBE is connected with the non-inverting terminal of LM324, all R1, R2, R3 and R4 are ordinary metal film resistors, if R2=R3,the output of the amplifier will be U0≈2UBE. In the device, both the 2 chips of LM324 can detect the input signal of 7 lines.



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