Negative rail in a TO-92 package
The LM79L05ACZ/LFT1 is a fixed -5V negative-output linear regulator from Texas Instruments, delivering up to 100 mA. It comes in a through-hole TO-92-3 package — the same footprint used for decades in audio preamps, industrial control cards, and legacy test equipment that need a clean negative bias rail. With a PSRR of 50 dB at 120 Hz, this part attenuates 120 Hz ripple from a full-wave rectified negative supply by a factor of ~316 — enough to keep the -5V rail quiet for an op-amp front end or a bipolar ADC reference.
The -5V output is fixed internally — no external resistor divider needed. Maximum input voltage is -35 V, so the part can drop from a -12V or -24V rail with plenty of headroom. Output current is limited to 100 mA; for loads above that, a higher-current negative regulator or a DC-DC converter with a negative output is required. Quiescent current is 6 mA typical — this is the current the regulator draws just to run its internal bias. In a battery-powered design drawing 100 mA from the negative rail, the Iq adds 6% overhead; for always-on rails the thermal impact is negligible in the TO-92 package. Built-in over-temperature and short-circuit protection mean the regulator survives an output short or a thermal overload without external crowbar circuitry — useful in prototyping or field-repairable equipment where the load may be miswired.
For volume BOM positions, we quote per RFQ with current pricing and lead time confirmed at the time of order.