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SMD code H305

Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables and published code lists.

H305 on a chip capacitor

3 µF, 50 V

3 µF, 50 V tantalum capacitor

A moulded tantalum capacitor: 305 is the capacitance in picofarads (3 µF) and H is the rated-voltage code (50 V). Makers disagree on the letter for 50 V: T at Kyocera AVX and Vishay, H at ROHM.

Check it with a meter

Lift one end and measure it on a capacitance range. A good one reads close to 3 µF. In circuit the meter also sees everything connected across it, so the reading means little until it is out. It is polarised: the band on the body marks the positive end, and a tantalum fitted backwards fails short, sometimes with a flame. A failed tantalum usually reads near 0 Ω both ways, often with a burnt or cracked body. A failed reading does not change what to fit: the marking still says 3 µF, 50 V. Fit the same capacitance at the same or a higher voltage.

On a transistor or diode body (SOT-23, SOT-23-5, TO-247), H305 is a part code instead. Those parts are listed below.

2 parts are printed H305

Not sure which one you have?

Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.

P-channel MOSFET, all SOT-23, 3 pins, all Blue Rocket.

Is it dead? One meter test per kind

Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.

P-channel MOSFET

Diode range, part lifted. Test drain to source first, then short gate to source and test again.

Working, it reads

Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.

Dead, it reads

  • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
  • The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
  • No body diode at all: failed open.
On the board
the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. Lift a leg to be sure.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

Printed with a code easy to misread as H305

One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.

Codes that begin with H305

For a marking with its end worn or burnt off. Each code has a page of its own.

Did you find your part?

Open this in the search to correct a character or try another package.