Negative rail regulator for analog signal chains
The Texas Instruments MC79L15ACLPR is a fixed -15 V output linear regulator delivering up to 100 mA. It is the negative complement to the 78Lxx series, designed to generate a clean negative supply rail from a -30 V maximum input. With 39 dB of power-supply rejection at 120 Hz, this part attenuates rectified line ripple by nearly 90× — sufficient to keep 60/120 Hz hum out of sensitive analog front-ends such as op-amp rails or ADC reference buffers.
Package, temperature grade, and protection
Housed in a TO-92-3 (TO-226AA) through-hole package with formed leads, the MC79L15ACLPR suits legacy board layouts and prototyping where surface-mount reflow is not available. The supplier device package is TO-92-3. Rated for 0°C to 125°C operating junction temperature, the part covers commercial and most industrial environments. On-chip protection includes over-temperature shutdown and short-circuit current limiting. The single regulator output is fixed at -15 V with no external resistor divider needed — the internal feedback network sets the voltage.