JAJSHO7A July 2019 – January 2021 INA253-Q1
PRODUCTION DATA
For this application, the INA253-Q1 measures current flowing through the speaker from the CLASS-D amplifier. The integrated shunt of 2 mΩ with an inductance of only 3 nH is an excellent choice for current sensing in speaker applications where low inductance is required. The low-inductive shunt enables accurate current sensing across frequencies over the audio range of 20 hz to 20 kHz.
The INA253-Q1 is setup in a bidirectional with the reference set to mid-supply as shown in Figure 7-9. The power supply to INA253-Q1 is setup at 5 V. The output of INA253-Q1 is set at 2.5 V. The INA253-Q1 with a gain of 100 mV/A, the INA253-Q1 output for a peak to peak of 10-A current the output of the INA253-Q1 will swing from 3.5 V to 1.5 V. The output can be directly connected to ADC input that has a full scale range of 5 V. The INA253-Q1 has a low THD+N of 0.1% at 1 kHz that enables distortion measurement of speaker. The INA253-Q1 can measure the impedance of the speaker and accurately measure the resonance frequency and peak impedance at resonance frequency. The INA253-Q1 can accurately track changes in impedance real time.