MAX5986B Datasheet | Maxim Integrated

Click here for production status of specific part numbers. MAX5986A- MAX5986C/ MAX5987A EVALUATION KIT AVAILABLE IEEE 802.3af-pliant, High-Efficiency, Class 1/Class 2, PDs with Integrated DC-DC Converter General Description The MAX5986A- MAX5986C/MAX5987A provide a plete power-supply solution as IEEE® 802.3afpliant Class 1/Class 2 Powered Devices (PDs) in a Power-over-Ethernet (Po E) system. The devices integrate the PD interface with an efficient DC-DC converter, offering a low external part count PD solution. The MAX5987A includes a low-dropout regulator and the MAX5986A- MAX5986C include sleep and ultra-low power modes. The PD interface provides a detection signature and a Class 1/Class 2 classification signature with a single external resistor. The PD interface also provides an isolation power MOSFET, a 60m A (max) inrush current limit, and a 323m A operating current limit. The integrated step-down DC-DC converter uses a peak current-mode control scheme and provides an easy-toimplement architecture with a fast transient response. The step-down converter operates in a wide input voltage range from 8.7V to 60V and supports up to 6.49W of input power. The MAX5986A/MAX5986B/MAX5987A operate at a fixed 215k Hz switching frequency and the MAX5986C operates at a fixed 430k Hz switching frequency. The DC-DC converter operates at a fixed switching frequency, with an efficiency-boosting frequency foldback that reduces the switching frequency by half at light loads. The devices feature an input undervoltage-lockout (UVLO) with wide hysteresis and long deglitch time to pensate for twisted-pair cable resistive drop and to assure glitch-free transition during power-on/off conditions. The devices also feature overtemperature shutdown, short-circuit protection, output overvoltage protection, and hiccup current limit for enhanced performance and reliability. The MAX5986A- MAX5986C/MAX5987A are available in a 16-pin, 5mm x 5mm, TQFN power package and operate over the...