LM5118EVAL/NOPB

User's Guide SNVA334B – April 2008 – Revised January 2014 AN-1819 LM5118 Evaluation Board 1 Introduction The LM5118 evaluation board is designed to provide the design engineer with a fully functional, Emulated Current Mode Control, buck-boost power converter to evaluate the LM5118 controller IC. The evaluation board provides a 12 V output with 3 A of output current capability. The evaluation board’s wide input voltage range is from 75 V to 5 V, with operation down to 3 V with some component changes. The evaluation board operates at 300 kHz, a good compromise between conversion efficiency, tradeoffs between buck and buck-boost mode requirements, and converter size. The board is constructed with FR4 material. This user's guide contains the evaluation board schematic and Bill of Materials (BOM). Refer to the LM5118 quick start (SNVU065) and for more complete circuit and design information, see Wide Voltage Range Buck-Boost Controller (SNVS566). The performance of the evaluation board is: • Input Range: 75 V to less than 5 V at full current • Operation to 3 V at reduced current and appropriate adjustments. Operation at full current to around 3 V is possible with current limit sense resistor, UVLO threshold, and corresponding Cramp adjustment. Additional input capacitance may be required. See the LM5118 datasheet (SNVS566) and quick start (SNVU065) for more details. • Output Voltage: 12 V • Output Current: 0 to 3 A • Frequency of Operation: 300 kHz • Board Size: 3.45 × 2.65 inches • Load Regulation: 1% • Line Regulation: 0.1% • Over-Current Limiting • Operation with VIN greater or less than VOUT 2 IC Features • • • • • • • • • • • • • Integrated high and low side driver Internal high voltage bias regulator Ultra-wide input voltage range: 5 V to 75 V Emulated current mode control Single inductor architecture VOUT operation below and above VIN Single resistor sets oscillator frequency Oscillator synchronization capability Programmable soft-start Ultra low (