16V fixed rail at 2A — the load it serves
The BAJ6DD0WHFP-TR from ROHM is a positive fixed-output linear regulator delivering 16V at 2A continuous. The 55dB PSRR at 120Hz tells the designer how well this part rejects full-wave-rectified ripple. 55dB at mains frequency is a moderate figure — adequate for a motor-drive control supply or a general-purpose analog rail, but not the first choice for a precision ADC reference path where 70dB+ would be expected. Dropout voltage is 0.7V maximum at 2A output, so the input rail must stay above 16.7V to maintain regulation at full load. That headroom requirement drives the transformer secondary voltage and the bulk capacitor bank on the input side.
Temperature grade and protection — where it survives
The operating temperature range spans -40°C to 125°C, placing it solidly in the industrial and automotive underhood envelope. The evidence does not carry an AEC-Q100 grade, so a buyer qualifying into a production vehicle must verify the qualification status with ROHM directly — capable is not qualified. Protection features include over-current, over-temperature, and over-voltage shutdown — a complete safety net for a 16V rail that might see load-dump spikes or a shorted downstream regulator. The enable pin gives the system designer a sequenced-power-up option.
Package reality — HRP-5 footprint and power dissipation
The HRP-5 package is a 5-lead surface-mount package with an exposed tab for thermal management. At 2A output and a typical dropout of 0.7V, the power dissipation is 1.4W — the copper area on the PCB under the tab sets the junction temperature. The 125°C junction limit means the designer must calculate the thermal resistance for their specific board stack-up. The ROHS3 compliance is confirmed.