The L4975A is a 5A output current, 5.1V to 40V output voltage range, 0 to 90% duty cycle range step-down monolithic power switching regulator that has internal feed-forward line regulation, internal current limiting, precise 5.1V ± 2% on chip reference, reset and power fail functions, soft start, input/output sync pin, under voltage lock out with hysteretic turn-on, PWM latch for single pulse per PE-RIOD, very high efficiency, switching frequency up to 500KHz, thermal shutdown, continuous mode operation.
The L4975A is a monolithic 5 A step‑down switching regulator with an adjustable output voltage from 5.1 V to 40 V. It integrates a DMOS output transistor, feed‑forward line regulation, soft‑start, current limiting, thermal shutdown, and reset/power‑fail functions, making it suitable for micro‑processor‑based systems.
The document lists absolute maximum ratings, detailed pin functions, electrical and thermal characteristics, mechanical dimensions, and typical performance data measured on an evaluation board. It also includes reset and power‑fail behavior and recommended external component values.
| Output Current | 5 A |
|---|---|
| Output Voltage Range | 5.1 V to 40 V |
| Switching Frequency | up to 500 kHz |
| Reference Voltage | 5.1 V ±2 % |
| Input Voltage (max) | 55 V |
| Efficiency (typical at 12 V) | ≈80 % |
| Thermal Shutdown Temperature | ≈150 °C |
The device uses a precise on‑chip reference of 5.1 V ±2 %.
It includes a soft‑start function and a current‑limit circuit that shuts off the power DMOS when the load current exceeds a preset threshold.
The regulator can operate at switching frequencies up to 500 kHz.