LM5033SD-EVAL

User's Guide SNVA091A – May 2004 – Revised May 2013 AN-1331 LM5033 Evaluation Board 1 Introduction The LM5033EVAL evaluation board provides the design engineer with a fully functional intermediate bus converter (IBC) employing a half-bridge topology. Configured as an IBC, the circuit operates open loop, resulting in an output voltage which tracks the input voltage. Operating open loop results in very high efficiency (>95%), since the circuit operates at maximum duty cycle, making best use of the transformer with minimal deadtime. IBCs are used to change a relatively high voltage (e.g., 48V) to a lower voltage (e.g., 9V) to power Pointof-Load (POL) regulators. Since many POLs are buck converters, which have higher efficiency when their input voltage is low, the combination of IBC+POLs provides higher overall system efficiency. Additionally, an IBC provides isolation which buck converters do not. This board’s specifications are: • Input voltage: 40V to 60V, 48V nominal • Output voltage: 7.5V to 11.3V, 9.0V nominal • Output current: 0 to 20A • Measured efficiency: 95.5% (40V