The L78M06CDT-TR is a fixed-output positive linear regulator from STMicroelectronics, delivering a regulated 6 V at up to 500 mA from a maximum input of 35 V. It integrates over-current, over-temperature, and short-circuit protection, making it suitable for unregulated supply rails where fault tolerance is required.
What the 59 dB PSRR means on the bench
The 59 dB power-supply rejection ratio at 120 Hz means the regulator attenuates 120 Hz ripple from a full-wave rectified input by a factor of roughly 900 — a 1 V pk-pk ripple at the input appears as about 1.1 mV pk-pk at the output. For a 6 V rail feeding an analog front-end, that keeps the line-frequency fundamental out of the signal band. The 6 mA quiescent current is the regulator's own draw at full load — it contributes to the thermal budget in the DPAK package, especially at higher input-output differentials.
Package, mounting, and board integration
Housed in a TO-252-3 (DPAK) surface-mount package with an exposed tab, the L78M06CDT-TR requires a copper-land area on the PCB to dissipate heat from the 500 mA output. The tab is the ground connection and should be soldered to a thermal pad with vias to inner or bottom-layer copper.
The operating temperature range of 0 °C to 125 °C covers commercial and industrial indoor environments but does not extend to automotive under-hood or military cold-start conditions.