SMD code 509d
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.
509d is a capacitor marking
5 pF
5 pF capacitor
50 followed by the multiplier 9, in picofarads: 5 pF. Printed this way on film and larger ceramic capacitors; small chip ceramics are usually not printed at all. D is the tolerance, ±0.5 pF.
Check it with a meter
Lift one end and measure it on a capacitance range. A good one reads close to 5 pF. In circuit the meter also sees everything connected across it, so the reading means little until it is out. A failed one usually reads near 0 Ω, or a steady low resistance, on the ohms range, often from a crack. On the board a shorted capacitor shorts its whole rail. A failed reading does not change what to fit: the marking still says 5 pF.
On a transistor or diode body (SMC, SOT-23-5, SOT-23-6), 509d is a part code instead. Those parts are listed below.
3 parts are printed 509d
Not sure which one you have?
Answer up to 4 quick questions and these 3 parts are ranked, with a meter test that settles it. It works on a dead part too.
Load switch, all Global Mixed-mode Technology. What differs:
G509L25NT11GSOT-23-55 pinsSOT-23-55 pins
- What it is
- Load switch
- Maker
- Global Mixed-mode Technology
- Package
- SOT-23-5
- Pins
- 5
- Details
- Power Distribution Switch
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Load switch.
G509L25NTP1GSOT-23-66 pinsSOT-23-66 pins
- What it is
- Load switch
- Maker
- Global Mixed-mode Technology
- Package
- SOT-23-6
- Pins
- 6
- Details
- Power Distribution Switch
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Load switch.
1 more part has no package on record
G509S30DTP1G6 pinsNot recorded6 pins
- What it is
- Load switch
- Maker
- Global Mixed-mode Technology
- Package
- Not recorded
- Pins
- 6
- Details
- Power Distribution Switch
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Load switch.
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.
Load switch
Voltage, board powered, black probe on ground.
Working, it reads
Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.
Dead, it reads
- Output at the input voltage while switched off: the pass element has shorted.
- Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
- On the board:
- An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
- 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 pinout and whether the enable is active high or low differ between parts. The datasheet gives both.
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 509d
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 509d
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.