2 Power Density

Power density is a term created to describe the power output of a device compared to its size. This is especially important in space constrained applications, or high functionality applications. These applications are mainly concerned with the space on the XY board area when talking about power density, but the Z (height) dimension can also be taken into consideration for total volume if desired. By shrinking the solution area, increasing the power output under similar conditions, or a combination of the two, the power density is positively impacted. As an example, comparing the 3-A rated parts in a case with 12 V on the input, 1.2 V on the output and in an ambient temperature of 65°C, the TPM8290x is able to give the full 3-A load for a power density of 110mA/mm². The TPS82130 provides 2.1 A for a power density of 72 mA/mm² due to more power losses in the device and the limited recommended junction temperature of 110°C vs 125°C. Section 3 provides additional detail of how the total solution size went from 29mm² for TPS82130 to a solution size of 25mm² in TPSM82903. Section 4 describes how efficiency and thermals impact how much power is able to get out of a part.