The VI Chip Bus Converter Module is a high efficiency (>94%), narrow input range Sine Amplitude Converter (SAC) operating from a 38 to 55 Vdc primary bus to deliver an isolated 3.17 V to 4.58 V secondary. The BCM may be used to power non-isolated POL converters or as an independent 3.17 4.58 V source. Due to the fast response time and low noise of the BCM, the need for limited life aluminum electrolytic or tantalum capacitors at the load is reduced--or eliminated--resulting in savings of board area, materials and total system cost. The BCM achieves a current density of 169 A/in3 in a VI Chip package compatible with standard pick-andplace and surface mount assembly process. The VI Chip package provides flexible thermal management through its low junction-to-board and junction-to-case thermal resistance. Owing to its high conversion efficiency and safe operating temperature range, the BCM does not require a discrete heat sink in typical applications. Low junction-to-case and junction-to-lead thermal impedances assure low junction temperatures and long life in the harshest environments.