PWM controller for buck and boost regulation
The Texas Instruments LM3524DM/NOPB is a PWM controller IC designed for both step-up (boost) and step-down (buck) switching regulator topologies. It integrates the control logic and a single transistor driver output on a single chip, operating from a supply rail of 8V to 40V.
The output configuration supports positive or negative rails, which is useful for generating a negative bias supply from a positive input bus, common in op-amp or LCD bias circuits.
It is not rated for -40°C cold-crank conditions — if the design must start at -40°C, look at the automotive-grade LM5150QURUMRQ1 instead. The 16-SOIC (0.154" body width, 3.90 mm) package is a standard surface-mount footprint shared by many PWM controllers.
Control features and topology limits
Control features include current limiting, an enable pin for shutdown, and frequency control — the latter lets you set the oscillator timing with an external RC network. There is no clock sync input, so synchronizing multiple converters to a common switching frequency requires external logic or a different controller. Synchronous rectification is not supported, so the external diode rectifier will dominate the thermal budget at higher output currents.
It is RoHS3 compliant (NOPB suffix). No official second-source alternate is listed in the record, but the UCC2806DWTR from TI is a functional peer in a similar package with a 50% duty cycle and dual outputs — verify pin compatibility before substituting.