Fixed 3.3 V LDO in a through-hole TO-220-5
The Linear Technology LT1963AET-3.3#06PBF is a single-output positive fixed 3.3 V low-dropout linear regulator rated for 1.5 A continuous output. It comes in a TO-220-5 through-hole package (Flow 6 variant), which suits benchtop supplies, industrial control boards, and power stages where a soldered or socketed through-hole part is preferred over surface-mount. The fixed 3.3 V output eliminates the need for external resistor dividers, simplifying the BOM for a dedicated 3.3 V rail.
Dropout voltage and PSRR — what they mean for the rail
Maximum dropout voltage is 0.55 V at 1.5 A load, so a 3.85 V input holds the 3.3 V output in regulation through brownout or cold-crank conditions. The 63 dB PSRR at 120 Hz provides meaningful ripple rejection from a rectified mains supply — useful when this LDO follows a bulk capacitor rather than a switching preregulator. Quiescent current is 1.5 mA typical, rising to 120 mA max under heavy load, which is typical for a 1.5 A LDO but worth budgeting in battery-powered designs.
Industrial temperature grade and protection set
Rated for -40°C to 125°C operating junction temperature, this part fits outdoor telecom cabinets, engine-bay electronics, and factory-floor motor drives. Built-in protection includes over-current, over-temperature, and reverse polarity — the reverse polarity clamp is a practical safeguard when the input rail can be miswired. An enable pin (active high) lets the system shut down the regulator for sequenced power-up or low-power standby.
Lifecycle and sourcing
The LT1963AET-3.3#06PBF carries an active lifecycle status and is RoHS3 compliant.