TLV320AIC26_08 Datasheet, PDF (31/67 Pages) Texas Instruments – LOW POWER STEREP AUDIO CODEC WITH HEADPHONE / SPEAKER AMPLIFIER AND 12-BIT BATTERY / TEMPERATURE / AUXILIARY ADC

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Temperature − °C
Figure 26. Typical Plot for Single Measurement Method
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TLV320AIC26
SLAS412− DECEMBER 2003
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Temperature − °C
Figure 27. Typical Plot for Differential Measurement Method
Battery Measurement
An added feature of the ’AIC26 is the ability to monitor the battery voltage on the other side of a voltage regulator (dc/dc
converter), as shown in Figure 28. The battery voltage can vary from 0.5 V to 6 V while maintaining the analog supply
voltage to the ’AIC26 in the range of 2.7 V to 3.6 V. The input voltage (VBAT1 or VBAT2) is divided by a factor of 6 so that
a 6.0-V battery voltage is represented as 1.0 V to the ADC. In order to minimize the power consumption, the divider is only
on during the sampling of the battery input. If the battery conversion results in a ADC output code of B, the voltage at the
battery pin can be calculated as
Vbat = (B/2^N) x 6 x Vref
where N is the programmed resolution of ADC and Vref the programmed value of internal reference or the applied external
reference.
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