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Compensation based on DS1859 and the MAX604 voltage regulator design drift
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Follow-up circuit for the regulator to provide continuous and stable voltage. Some applications accept a relatively large voltage fluctuations, and some applications are very demanding on the voltage fluctuations, these circuits require precise voltage constant. This article will compare the standard configuration of the regulator, and coupled with DS1859 dual temperature resistance with a voltage regulator after the test data. DS1859 with the way in which temperature control variable resistor and the look-up table (LUT) for temperature compensation, from the test results can be clearly seen that the index lookup table using DS1859 temperature indicators on the system improvement. Simpler chips, such as the DS1847 dual temperature nonvolatile variable resistor with a temperature index of the same lookup table, the effect is the same excellence. In addition, DS1859 and DS1847 to the conditions of the microcontroller without the need to provide closed loop control. Non-compensation regulator A typical voltage regulator circuit includes adjusting the components, the feedback resistor divider and the transient load conditions, or switch to play a certain role and used as a filter to adjust the load capacitance. Feedback resistor network settings based on the ratio of two resistors regulator output voltage. In this article, use MAX604 as a regulator, it can preset 3.3V output voltage or any voltage within the scope of work. Partial pressure by controlling the SET pin, MAX604 output voltage using the voltage divider decision. Most of the regulator circuit, the output voltage changes slightly with temperature. MAX604 changes in nominal output voltage range of 97.6 to 101.5%, from the circuit in Figure 1 the experimental data can be confirmed. At -45 ° C, the output value of about 98% of the nominal value; to +85 ° C, the output value of the nominal value of 101%. Most of the output regulator with similar temperature characteristics, the following discussion of the ways how to improve this indicator. Conclusion The use of temperature lookup table can easily increase the index temperature characteristics of the system, eliminating the temperature change. Because the number of resistance by the non-volatile memory stored in a separate lookup table control, each resistor can be completely in accordance with the user applications. In addition to providing a flexible set of two-channel outside, DS1859 also provides three-way ADC inputs to monitor external voltage.