Negative rail regulator with 1.5 A continuous output
The LM337SP is a negative adjustable linear regulator from STMicroelectronics, delivering 1.5 A continuous output current with an output range from -1.2 V down to -37 V. It provides a PSRR of 77 dB at 120 Hz, rolling off to 60 dB at higher frequencies — a meaningful spec when the negative rail must reject rectified ripple in audio or instrumentation supplies.
Output range and protection
The adjustable output is set with two external resistors; the minimum fixed voltage is -1.2 V, and the maximum output is -37 V, limited by the 40 V maximum input. Built-in over-current and over-temperature protection circuits guard against output shorts and thermal runaway, reducing the need for external clamp diodes in many designs.