Ultra-low Iq LDO for always-on and battery rails
The Texas Instruments TPS7A0328DQNR is a fixed-output low-dropout linear regulator delivering 2.8 V at up to 200 mA. Its defining characteristic is a quiescent current of 300 nA, which makes it a fit for battery-powered equipment, energy-harvesting nodes, and microcontroller keep-alive rails where every microamp of standby draw matters. The 55 dB PSRR at 1 kHz gives it enough ripple rejection to supply noise-sensitive analog blocks like sensor front-ends or low-power ADCs without a post-filter.
Dropout and headroom — what 0.36 V means for your rail budget
Maximum dropout voltage is 0.36 V at the full 200 mA load. The input rail must stay above 2.8 V plus dropout to maintain regulation.
Package and layout — 1x1 mm X2SON
The part comes in a 4-X2SON package measuring 1x1 mm (supplier device package 4-X2SON). The exposed pad underneath must be soldered to a PCB thermal land for heat dissipation.
Protection and control features
Built-in protection includes over-current limiting, thermal shutdown, and under-voltage lockout (UVLO). The enable pin allows external on/off control, letting a system controller gate the regulator to cut standby current to near zero when the rail is unused. These protections cover the common fault modes: a shorted load, a stalled fan, or a brown-out input.
Temperature range — rated for industrial environments
Operating junction temperature range is -40°C to 125°C, covering industrial, outdoor telecom, and automotive cabin-domain applications. The 125°C junction limit means the part can be used near hot components or in enclosures with limited airflow, provided the PCB copper area keeps the junction below that ceiling at full load.