1.5A fixed 5V rail — the 7805 that defined the standard
The Texas Instruments LM7805CT/NOPB is the through-hole 7805 that set the benchmark for 5V linear regulation. It delivers a fixed 5V output at 1.5A continuous from a TO-220-3 package — the same pinout and footprint that has been the default 5V rail for four decades. The 35V maximum input covers 12V, 24V, and even unregulated rectified supplies up to 30V with margin.
80dB ripple rejection — why this matters for analog supplies
The 80dB PSRR at 120Hz is the key spec for anyone feeding this regulator from a full-wave rectified supply. 80dB means the 120Hz ripple on the input is attenuated by a factor of 10,000 — a 1Vpp ripple at the input becomes 100µVpp at the output. This is why the 7805 has been the go-to for powering op-amps, ADCs, and other analog circuits that would otherwise couple line-frequency hum into the signal chain. The dropout voltage is 2V maximum at 1A load. This sets the minimum input voltage for regulation at 7V (5V + 2V). Below that, the output follows the input minus the dropout — the regulator drops out of regulation.
Built-in protection suite — over-current, thermal, short-circuit
Three protection features are integrated: over-current limiting folds back the output current during a fault, over-temperature shutdown protects the die at ~165°C junction, and short-circuit protection limits the fault current without destroying the pass transistor. This means the regulator survives a sustained output short without external protection diodes in most applications. The quiescent current is 6 mA — this is the ground pin current that flows regardless of load. At light loads (10 mA), the regulator's own draw is significant; at 1A load it's negligible. The 0°C to 125°C operating junction temperature range is the commercial grade; the actual ambient ceiling depends on the heatsink and power dissipation.
Active production — sourcing and compliance
The part is ROHS3 Compliant and carries the NOPB (lead-free) finish.
