KEC

KEC semiconductors in stock at YILUDA TECH. Twenty-eight KEC lines are held as 100% original, new and unused material, covering zeners, small-signal transistors, regulators, SRAM and discrete power devices.

What is stocked

Zeners and protection — KDZ3.0V, KDZ3.3V and KDZ5.1V in SOD323, PG05HAS23-RTK/P ESD diode in SOT23.
Transistors — KRC101S-RTK/P digital transistor, KMA3D0N20SA-RTK/P MOSFET, KTD1630G in TO247.
Diodes — KDS226-RTK/P switching diode.
Regulators and memory — KIA7805AF-RTF/P, a 5 V 1 A three-terminal regulator in TO252, and KM6161002CJ-12 SRAM in SOJ44.

The digital transistor trap

KRC101S is a resistor-equipped transistor: the bias resistors are built into the package, and the input is driven directly from a logic pin without external components. Replacing it with a plain bipolar transistor of similar ratings produces a circuit that either never turns on or turns on weakly, because the base current path the designer relied on is no longer there. The same logic applies in reverse: fitting a digital transistor where a plain one belongs adds an unintended divider. Read the KRC, KRA and KRD prefixes as a different component class, not a different brand of the same part.

Regulators and suffixes

KIA7805AF is the 5 V member of the classic three-terminal family, with A marking the improved tolerance grade and F the package. The -RTF/P and -RTK/P suffixes denote packaging and are not electrical variants, which is convenient; the trap lies in assuming the same for the voltage suffix on the zeners, where KDZ3.3V and KDZ5.1V differ by 1.8 volts of clamping behaviour and nothing else in the code changes.

Ordering notes

Quote the full code including the -RTK/P or -RTF/P packaging suffix where it appears.
Zener voltage is part of the model number, not a datasheet lookup.
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