DAC VREF dependency

TRCooper — Mon, 24 Nov 2025 15:27:00 GMT

Using LPC553x for a low power application. Reference Manual Rev 3, 07/2023. Paragraph 48.1.4 DAC Chip-specific Initialization states: "Enable VREF module... DAC PTAT and ZTC current sources come from VREF module." What is the lowest power configuration of VREF that is needed for use of the DACs? Does VREF buffering need to be enabled? Using external reference for DAC reference select but DAC still apparently requires VREF for current source. Is there guidance regarding selection of PTAT vs ZTC, and what the tradeoffs are? Thanks.

Re: DAC VREF dependency

Omar_Anguiano — Wed, 26 Nov 2025 22:36:29 GMT

For minimum power, you can configure VREF in bandgap-only mode and disable unnecessary features. Buffering is not required if you are not using VREF_OUT as the DAC reference.
More details for VREF, please refer to the attached presentations on this post: LPC5536: on DAC current sources (ZTC, PTAT)

BR,
Omar

LPC Microcontrollers中的主题 DAC VREF dependency

DAC VREF dependency

Re: DAC VREF dependency