LM5171 is a 280kHz switching regulator from Shanghai ZHONGHAN Electronics Technology Co.,Ltd. It has a high efficiency, 1.5A integrated switch and a wide input voltage range (2.7V to 30V). The chip's design is flexible and can be used in most power supply configurations, including boost, flyback, forward, inverting, and SEPIC.
The LM5171 is a 1.5 A boost regulator that operates at a nominal 280 kHz switching frequency. It supports a wide input voltage range of 2.7 V to 30 V and includes features such as frequency fold‑back, thermal shutdown, and easy external synchronization.
The document provides absolute maximum ratings, detailed electrical characteristics, typical performance curves, and design notes on current‑mode control, slope compensation, sub‑harmonic oscillation mitigation, soft‑start implementation, and thermal calculations.
| Input Voltage Range | 2.7 V to 30 V |
|---|---|
| Operating Frequency (typical) | 280 kHz |
| Shutdown Threshold Voltage | 0.50 V to 1.20 V |
| Thermal Shutdown Temperature | 180 °C |
The LM5171 operates at a nominal frequency of about 280 kHz.
It supports an input voltage from 2.7 V up to 30 V.
It uses frequency fold‑back and a current limit that reduces the duty cycle when the switch current exceeds the set limit.
The shutdown threshold voltage is between 0.50 V and 1.20 V.