The DACx760 family operates within the specified single-supply range of 10 V to 36 V applied to the AVDD pin. The device also operates with the specified dual-supply range of 10 V to 18 V applied to AVDD, and 0 V to –18 V on AVSS, or any subsequent combination that does not exceed the maximum difference of 36 V between AVDD and AVSS. The digital supply, DVDD, operates within the specified supply range of 2.7 V to 5.5 V or is powered by the internal 4.6-V LDO.
Switching power supplies and DC/DC converters often have high-frequency glitches or spikes riding on the output voltage. In addition, digital components can create similar high frequency spikes. This noise can be easily coupled into the DAC output voltage or current through various paths between the power connections and analog output. To further reduce noise, include bulk and local decoupling capacitors.
The DACx760 has internal power-on reset (POR) circuitry for both the digital DVDD and analog AVDD supplies. This circuitry makes sure that the internal logic and power-on state of the DAC power up to the proper state independent of the supply sequence. The recommended power-supply sequence is to first have the analog AVDD supply come up, followed by the digital DVDD supply. DVDD can come up first as long as AVDD ramps to at least 5 V within 50 μs. If neither condition can be satisfied, issue a software reset command using the SPI bus after both AVDD and DVDD are stable.
The current consumption on the AVDD and AVSS pins, the short-circuit current limit for the voltage output, and current ranges for the current output are listed in Section 7.5. The power supply must meet the requirements listed in Section 7.5.