3.3V rail at 1.1A — the dropout and PSRR story
The LT1965EDD-3.3#TRPBF is a fixed 3.3V output LDO regulator rated for 1.1A continuous output current. PSRR is 75dB at 120Hz, which is the rectified line-frequency ripple that leaks through a bulk capacitor. For an analog supply rail powering a 16-bit ADC or a precision op-amp chain, that rejection keeps 120Hz ripple off the sensitive circuitry without needing a post-filter LC stage.
Package and rework — the 8-DFN exposed pad
The 8-WFDFN package (3x3mm body, 8-DFN supplier device package) has an exposed pad on the bottom that serves as the thermal path and the ground connection. Without that via pattern, the 1.1A load at high ambient will hit the thermal limit before the current limit. Rework note: the exposed pad makes hand rework trickier than a standard SOIC. Preheating the board to 100-120°C before hitting the package with hot air reduces the risk of lifting the pad. The pin 1 indicator is a small dot on the top surface — confirm orientation before placing, because the DFN has no chamfered edge on the short side.
Industrial temperature range and protection
The protection set — over-current, over-temperature, and reverse polarity — covers the common field faults: a shorted load, a lost heatsink, or a backwards battery connection on the input.