Negative rail in a SOT-223-4 footprint
The LM337IMPX/NOPB is a negative adjustable linear regulator from Texas Instruments, delivering up to 1.5 A output with an adjustable range from -1.2 V down to -37 V. The SOT-223-4 surface-mount package fits into compact PCB layouts.
The 60 dB PSRR at 120 Hz means this regulator attenuates full-wave-rectified ripple by a factor of 1000. For a -15 V rail feeding an op-amp front end, that keeps the 120 Hz hum component well below the noise floor of a 16-bit ADC. If the design already has a post-filter LC stage, the 60 dB figure gives you margin to relax the inductor DCR or capacitor ESR budget.
Output voltage range and current — sizing the rail
The minimum output is -1.2 V (the internal reference voltage), and the maximum is -37 V, set by two external resistors. The 1.5 A output current rating is continuous; the part includes over-temperature and short-circuit protection.
The SOT-223-4 package has a thermal pad on the tab; a 1-inch² copper pour on the PCB drops the thermal resistance enough to deliver 1.5 A at 125°C ambient without hitting the thermal shutdown threshold.
For volume production, the Tape & Reel option (standard for SOT-223-4) keeps the pick-and-place running without a reel change.