LM337Adjustable negative regulator

LM337 is an adjustable negative linear regulator in the 1.5 A class. It maintains approximately −1.25 V from OUTPUT to ADJ; two resistors establish the output relative to the common return. Its nominal adjustment span is −1.25 to −37 V with sufficient headroom, load and cooling. The front-view TO-220 pins are ADJ, IN and OUT. The metal tab is connected to the negative input. In SOT-223, the broad input tab is also numbered 4, so all four physical contacts are mapped here. This reference follows TI LM337-N, with LM337T/NOPB and LM337IMP/NOPB package views. A −9 V-to−5 V example shows the divider, required output capacitor and reversed capacitor polarity. The SMD order has an extended temperature range, but the common electrical table below retains the datasheet’s stated 0–125°C LM337-N conditions.