SMD code P122
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.
P122 on a chip capacitor
0.12 pF
0.12 pF capacitor
The p is both the decimal point and the unit: 0.12 pF.
Check it with a meter
Lift one end and measure it on a capacitance range. A good one reads close to 0.12 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 0.12 pF.
On a transistor or diode body (SOT-23-5, SOT-89, SOT-223), P122 is a part code instead. Those parts are listed below.
The only part printed P122 in our tables
PGA-122-75+
- What it is
- RF amplifier (MMIC)
- Maker
- Mini-Circuits
- Package
- SOT-89
- Pins
- 3
- Details
- MMIC amplifier, 4-1500 MHz
- Source
- Manufacturer datasheet
Is it dead?
Voltage, board powered, on the output pin that the bias resistor or choke feeds.
Working, it reads
The output pin sits at the device voltage the datasheet gives, a few volts, below the supply.
Dead, it reads
- Output pin at 0 V, or near 0 Ω to ground with the power off: shorted inside.
- Output pin at the full supply voltage: open inside, no current flowing.
- On the board:
- Measured on the board with power on; the bias network is part of the reading.
- 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 figures depend on the part and its bias resistor. 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.
Was it this one?
Codes that begin with P122
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.