Adjustable LDO with 200 mA output and wide PSRR bandwidth
The TPS79901DDCT is a single-output adjustable positive LDO from Texas Instruments, rated for 200 mA continuous output. Its 60 µA quiescent current makes it practical for always-on supply rails where the regulator's own draw must stay below the system sleep budget. The output voltage is adjustable from a 1.2 V minimum up to the input rail maximum of 6.5 V, set by an external resistor divider. The 0.18 V maximum dropout at full load means the input rail needs only 200 mV of headroom above the target output to stay in regulation. Power-supply rejection ratio is specified at 70 dB at 100 Hz, rolling off to 38 dB at 100 kHz — this profile matters when the LDO is cleaning up ripple from a switching pre-regulator, particularly in RF or analog front-end supplies where the switching fundamental falls in the 100 kHz to 1 MHz range.
Protection set and operating range
On-chip protection includes over-current limiting, over-temperature shutdown, reverse-polarity protection, and under-voltage lockout (UVLO). The UVLO prevents the output from turning on until the input rail is high enough to keep the pass element in its linear region, avoiding brown-out conditions on start-up. Operating temperature spans -40°C to 125°C, covering the industrial and automotive ambient range.
Supplied in a SOT-23-5 Thin (TSOT-23-5) package, the TPS79901DDCT mounts on a standard surface-mount footprint. The thin profile suits height-constrained assemblies where a standard SOT-23 body would exceed the clearance limit. Cut Tape suits prototype or low-volume builds where the full reel count is not needed.
For new designs this part is a straightforward BOM fit.