Chip internal reference voltage calibration method and device

Abstract

The invention discloses a chip internal reference voltage calibration method and device. The method comprises the steps: acquiring the analog quantity of reference voltage provided by a burning devicethrough an AD reference source interface; acquiring voltage information pre-burnt in the chip, wherein the voltage information comprises a voltage value of the reference voltage; obtaining the maximum output digital quantity of an AD converter, wherein the maximum output digital quantity is determined by the digit of the AD converter; based on the analog quantity of the reference voltage, performing analog-to-digital conversion on the reference voltage in the chip to obtain a digital quantity corresponding to the reference voltage; calculating the voltage value of the reference voltage according to the voltage value of the reference voltage, the maximum output digital quantity and the digital quantity corresponding to the reference voltage; and storing the voltage value of the reference voltage. By implementing the embodiment of the invention, the calibration of the reference voltage in the chip can be realized, the measurement error of the AD converter caused by the process difference of the chip is reduced, and the implementation cost is reduced.

Description

technical field [0001] The present application relates to the field of voltage measurement, in particular to a method and device for calibrating an internal reference voltage of a chip. Background technique [0002] The chip integrates multiple channels of AD converters and a bandgap reference voltage source (hereinafter referred to as "reference voltage"). This reference voltage can be used in many aspects, such as: for external voltage detection, as an internal AD converter reference sources, etc. When the reference voltage is used as the reference source of the AD converter, although the standard value of the reference voltage is uniformly marked as a typical value, due to the difference in the process of the chip, it cannot be guaranteed that the actual value of the reference voltage inside each chip is equal to the typical value , but when actually used to measure the external voltage to be detected, the AD converter still performs analog-to-digital conversion calculat...

AI Technical Summary

Problems solved by technology

When the reference voltage is used as the reference source of the AD converter, although the standard value of the reference voltage is uniformly marked as a typical value, due to the differences in the chip process, it cannot be guaranteed that the actual value of the reference voltage inside each chip is equal to the typical value , but when actually used to measure the external voltage to be detected, the AD converter still performs analog-to-digital conversion calculations with typical values, which will inevitably lead to a certain error between the measured voltage value and the actual value of the voltage to be detected

[0003] At present, in order to solve the problem of reference voltage differences caused by differences in the chip's own process, an independent reference source with higher precision is often used outside the chip to replace the internal reference voltage of the chip as the reference source of the AD converter. Not only is the cost high, but the reference source is easily affected by factors such as temperature drift, and it is difficult to maintain a stable value during the process of measuring the voltage to be detected. Therefore, it will also cause a certain measurement error

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