SBVS484A June 2025 – July 2026 TLV7A03
PRODUCTION DATA
Circuit reliability demands proper consideration be given to device power dissipation and location of the circuit on the printed circuit board (PCB). Verify correct sizing of the thermal plane. Make sure the PCB area around the regulator is as free as possible of other heat-generating devices that cause added thermal stresses.
As a first-order approximation, power dissipation in the regulator depends on the input-to-output voltage difference and load conditions. Use Equation 2 to approximate PD:
Power dissipation is minimized, and thus greater efficiency achieved, by proper selection of the system voltage rails. Proper selection allows the minimum input-to-output voltage differential to be obtained. The low dropout of the TLV7A03 allows for maximum efficiency across a wide range of output voltages.
The main heat conduction path for the device is through the thermal pad on the package. As such, solder the thermal pad to a copper pad area under the device. This pad area contains an array of plated vias that conduct heat to any inner plane areas or to a bottom-side copper plane.
The maximum power dissipation determines the maximum allowable junction temperature (TJ) for the device. According to Equation 3, power dissipation and junction temperature are most often related by the junction-to-ambient thermal resistance (RθJA). The RθJA component is the combined PCB and device package and the temperature of the ambient air (TA). Equation 4 rearranges Equation 3 for output current.
Unfortunately, this thermal resistance (RθJA) is highly dependent on the heat-spreading capability built into the particular PCB design. Therefore, RθJA varies according to the total copper area, copper weight, and location of the planes. The RθJA recorded in the Thermal Information table is determined by the JEDEC standard, PCB, and copper-spreading area. This value is only used as a relative measure of package thermal performance. For a well-designed thermal layout, RθJA is actually the sum of the X2SON package RθJC(bot) plus the thermal resistance contribution by the PCB copper. RθJC(bot) is the junction-to-case (bottom) thermal resistance.