ZHCSHR1A September 2017 – February 2018 TPS7A54-Q1
PRODUCTION DATA.
At 4.0 A and 0.9 VOUT, the dropout of the TPS7A54-Q1 has a 240-mV maximum dropout over temperature; thus, a 300-mV headroom is sufficient for operation over both input and output voltage accuracy. At full load and high temperature on some devices, the TPS7A54-Q1 can enter dropout if both the input and output supply are beyond the edges of the respective accuracy specification.
For a 0.9-V output. use external adjustable resistors. See the resistor values in listed Table 5 for choosing resistors for a 0.9 V output.
Input and output capacitors are selected in accordance with the Recommended Capacitor Types section. Ceramic capacitances of 47 µF for the input and one 47-µF capacitor in parallel with two 10-µF capacitors for the output are selected.
To satisfy the required start-up time and still maintain low noise performance, a 100-nF CNR/SS is selected. Equation 9 calculates this value.
At the 4.0-A maximum load, the internal power dissipation is 1.2 W and corresponds to a 52°C junction temperature rise for the RGR package on a standard JEDEC board. With a 55°C maximum ambient temperature, the junction temperature is at 107.0°C. To further minimize noise, a feed-forward capacitance (CFF) of 10 nF is selected.