Datasheet ACS756xCB (Allegro) - 9

Fully Integrated, Hall-Effect-Based Linear Current Sensor IC ACS756xCB with 3 kVRMS Voltage Isolation and a Low-Resistance Current Conductor CHOPPER STABILIZATION TECHNIQUE
Chopper Stabilization is an innovative circuit technique that is result of this chopper stabilization approach, the output voltage used to minimize the offset voltage of a Hall element and an asso- from the Hall IC is desensitized to the effects of temperature and ciated on-chip amplifier. Allegro’s Chopper Stabilization tech- mechanical stress. This technique produces devices that have an nique nearly eliminates Hall IC output drift induced by tempera- extremely stable Electrical Offset Voltage, are immune to thermal ture or package stress effects. This offset reduction technique is stress, and have precise recoverability after temperature cycling. based on a signal modulation-demodulation process. Modulation is used to separate the undesired DC offset signal from the mag- This technique is made possible through the use of a BiCMOS netically induced signal in the frequency domain. Then, using process that allows the use of low-offset and low-noise amplifiers a low-pass filter, the modulated DC offset is suppressed while in combination with high-density logic integration and sample the magnetically induced signal passes through the filter. As a and hold circuits. Regulator Clock/Logic Low-Pass Hall Element d Filter an Amp le ld mp Ho Sa
Concept of Chopper Stabilization Technique
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