Abstract: The DS4830 optical microcontroller's analog-to-digital converter (adc) offset can change with temperature and gainselection. However, the DS4830 allows users to measure the adc internal offset. The measured adc offset is added to the adcoffset register to nullify the offset error. This application note demonstrates the DS4830's adc internal offset calibration in theapplication program.
High input impedance and a wide input range are twohighly desirable features in a precision analog-to-digitalconverter, and the LTC®2449 delta-sigma adc has both.With just a few external components, the LTC2449 formsan exceptional measurement system with very high inputimpedance and an input range that extends 300mV beyondthe supply rails.
The 14-bit LTC2351-14 is a 1.5Msps, low power SARadc with six simultaneously sampled differential inputchannels. It operates from a single 3V supply and featuressix independent sample-and-hold amplifi ers and a singleadc. The single adc with multiple S/HAs enables excellentrange match (1mV) between channels and channel-tochannelskew (200ps).
Many 8-bit and 16-bit microcontrollers feature 10-bitinternal adcs. A few include 12-bit adcs, but these oftenhave poor or nonexistent AC specifi cations, and certainlylack the performance to meet the needs of an increasingnumber of applications. The LTC®2366 and its slowerspeed versions offer a high performance alternative, asshown in the AC specifi cations in Table 1. Compare theseguaranteed specifi cations with the adc built into yourcurrent microcontroller.
The STM32F10xxx microcontroller family embeds up to three advanced 12-bit adcs (depending on the device) with a conversion time down to 1 μs. A self-calibration feature is provided to enhance adc accuracy versus environmental condition changes.
