Description
The NCL31010 is a member of the onsemi Power over Ethernet
Powered Device (PoE−PD) product family and integrates an IEEE
802.3bt PoE−PD interface controller, a dual step−down converter and a
buck convertor LED driver. The NCL31010 incorporates all the
required functions for operation within a PoE system such as detection,
classification and current limiting during the inrush phase. The
NCL31010 contains synchronous step−down DC/DC converters for the
main 3.3 V system supply as well as an auxiliary supply. In addition, the
NCL31010 also integrates a current mode buck DC/DC controller
designed to operate as a LED driver. The LED driver supports both
PWM dimming and high−bandwidth analog dimming.
The NCL31010 supports high−power applications (up to 90 W PoE).

Features
• Fully Supports IEEE 802.3af/at and 802.3bt Specifications
• Assigned Power Level Up to 90 W
• Proprietary 100 W+ Applications
• Supports Autoclass
• HV Maintain Power PWM Output (MPS)
• Integrated 3.3 V Buck Convertor
• Integrated Adjustable Buck Convertor 2.5 − 24 V
• Integrated High Efficiency Buck LED Driver
• Adjustable Switching Frequency 44.4 kHz to 1 MHz
• Deep Dimming to Zero with Accuracy of 0.1% Using Internal
Precision 2.4 V Reference
• Best in Class Linearity
• High Modulation Bandwidth (~50 kHz)
♦ Visual Light Communication Capable
♦ Yellow−Dot Compliant
• Internal DIM DAC for Independent LED Control During
Micro−controller Re−flashing (Warm Boot)
• Low EMI Reference Design
• I2C/SPI Interface (NCL31010I/NCL31010S)
• High Accuracy Diagnostic Functions to Measure Voltages/Currents
• Protection against LED Shorts & Opens
• LED Over/Under Voltage & Over Current Protection
• Chip Over Current Protection
• Chip & LED Over Temperature Protection
• Junction Temperature Range of −40°C to +125°C
• Available in 48−pin QFN 7x7
• These Devices are Pb−Free and are RoHS Compliant