AS39513 datasheet(13/108 Pages) AMSCO

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ams Datasheet

Page 13

[v1-10] 2018-Apr-25

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AS39513 − Detailed Description

Temperature Sensor

The on-chip temperature sensor is configured and calibrated to

measure temperatures between -20ºC to 55ºC. The gold

bumped die achieve an accuracy TACCGB. The on-chip sensor can

be reconfigured for a number of different temperature ranges

but the sensor requires recalibration after each temperature

range change.

The temperature sensor is intended to be used in logging mode.

The temperature sensor accuracy is only guaranteed in this

mode and not in the presence of a strong RF field from a reader.

When placed in the presence of a reader, strong RF fields can

cause self heating of the chip depending on the field strength,

antenna and length of time in the field. The accuracy of the

on-chip temperature sensor can then not be guaranteed.

External Sensor

The on-chip external sensor interface provides a means for

using both resistive and voltage-based sensors. The voltage at

the sensor node can be scaled and shifted in order to cover a

voltage range of VSEXT, or a subset of that range.

The external sensor input SEXT can be also used for

event-triggered logging. In this condition the logging is not

triggered in predefined time intervals from the internal timer,

but can be triggered externally, either with a sensor, switch or

a microcontroller.

The SEXT has in fact a very low power sensing interface that can

be used to trigger logging events when the sensor voltage

crosses one of four selectable thresholds. In addition an

optional drive current can be supplied to the sensor.

The maximum allowable voltage on the SEXT pin is VINSEXT.

Analog to Digital Converter

The chip has an integrated 10-bit analog to digital converter

(ADC) with selectable voltage references. It is used for voltage

conversion from the temperature sensor, the external sensor,

and the external battery voltage.

AS39513 Fiches technique(PDF) 13 Page - ams AG