SBAS649B June 2021 – June 2022 DAC12DL3200
PRODUCTION DATA
The device requires three different power-supply voltages. 1.8 VDC is required for the VDDA18A, VDDA18B, VDDCLK18, VDDIO, and VDDSYS18 power buses, 1.0 VDC is required for the VDDCLK10, VDDDIG, VDDEA, VDDEB, VDDHAF, VDDL2A and VDDL2B power buses and -1.8 VDC is required for the VEEAM18 and VEEBM18 power buses.
The recommended power-supply architecture uses high-efficiency switching converters to step down the voltage from a higher rail, followed by a second stage of regulation to provide switching noise reduction and improved voltage accuracy.
TI WEBENCH® Power Designer can be used to select and design the individual power-supply elements needed: see the WEBENCH® Power Designer
Recommended switching regulators for the first stage include the TPS82084 and similar devices.
Recommended low dropout (LDO) linear regulators include the TPS7A91 and similar devices.
Recommended dual positive and negative low dropout (LDO) linear regulator with an integral charge pump include the LM27762 and similar devices.
The switcher output should use a filter designed with a notch frequency that aligns with the switching ripple frequency of the DC/DC converter. Make a note of the switching frequency reported from WEBENCH® and design the EMI filter and capacitor combination to have the notch frequency centered as needed.
Do not share VDDDIG with the analog supply voltages in order to prevent digital switching noise from coupling into the analog signal chain. If some supplies are shared, apply careful power supply filtering to limit digital noise at the analog supply pins.
Several power buses can be combined to use a common regulator when using some type of isolation.