Modern JFET Replacement for TIS88A in Tuner Front Ends: PN4416, 2N4416, MMBFJ310 Options

User question

what is a good modern replacement for a TIS88A JFET for use in tuner front ends

Artificial Intelligence Response

Direct answer to the question

A very good modern replacement for a TIS88A in a tuner front end is the InterFET PN4416 if you want a through-hole TO-92 part, or the InterFET 2N4416 if a TO-72 metal can is acceptable. It is the closest currently listed part family I found that still has the right RF-oriented VHF specs, not just generic JFET parameters. The match is unusually close: the TIS88A is a 30 V-class VHF/UHF JFET with IDSS = 5 to 15 mA, gfs = 4.5 to 7.5 mS, Ciss = 4.5 pF, Crss = 1.0 pF, 18 dB / 10 dB power gain at 100/400 MHz, and 2 dB / 4 dB noise figure at 100/400 MHz; the 2N4416 family is essentially in the same class with IDSS = 5 to 15 mA, gfs = 4.5 to 7.5 mS, Ciss = 4 pF, Crss = 0.8 pF, and the same 18 dB / 10 dB gain and 2 dB / 4 dB NF figures at 100/400 MHz. (datasheet4u.com)

If you are willing to use an SOT-23 adapter and rebias the stage, the onsemi MMBFJ310LT1G / SMMBFJ310LT3G is a good current-production alternative, but it is not the closest electrical substitute. Its IDSS of 24 to 60 mA and gfs of 8 to 18 mS are much higher than the TIS88A, so it will usually need source-resistor and possibly neutralization/alignment changes. DigiKey currently lists MMBFJ310LT1G as Active. (digikey.com)

I would not make 2N5486 my first recommendation in 2026. It is reasonably similar on paper, but DigiKey lists 2N5486G as obsolete / no longer manufactured. (digikey.com)

---

Detailed problem analysis

The important point is that a tuner-front-end JFET is not selected only by “N-channel JFET” and rough \(I_{DSS}\). For FM/VHF tuner work, the replacement must also have suitable:

• RF transconductance at VHF/UHF
• low input and reverse-transfer capacitance
• known noise figure in the 100 to 400 MHz region
• similar operating current class, so the original self-bias network still lands in the right region. (datasheet4u.com)

The original TIS88A datasheet shows it was explicitly intended for VHF/UHF amplifiers, oscillators, and mixers, with RF parameters specified at 100 MHz and 400 MHz. That makes it a true RF front-end device, not just a low-frequency small-signal JFET. (datasheet4u.com)

That is why the 2N4416 / PN4416 family stands out. Its published RF numbers are almost a line-by-line overlay of the TIS88A numbers:

• TIS88A: IDSS 5–15 mA; gfs 4.5–7.5 mS; Ciss 4.5 pF; Crss 1.0 pF; Gps 18 dB @ 100 MHz and 10 dB @ 400 MHz; NF 2 dB @ 100 MHz and 4 dB @ 400 MHz. (datasheet4u.com)
• 2N4416 / PN4416: IDSS 5–15 mA; gfs 4.5–7.5 mS; Ciss 4 pF; Crss 0.8 pF; Gps 18 dB @ 100 MHz and 10 dB @ 400 MHz; NF 2 dB @ 100 MHz and 4 dB @ 400 MHz. (mouser.com)

From an RF design standpoint, that is about as close as you can realistically ask for in a replacement. The small capacitance difference is minor enough that the front end will usually still behave sensibly, though a touch-up alignment may still be worthwhile. That conclusion is an engineering inference from the near-match in RF parasitics and gain/noise data. (datasheet4u.com)

By contrast, the J310/MMBFJ310 family is more of a “high-gm RF substitute” than a real like-for-like replacement. It is attractive because it remains available in modern SOT-23 packages, but electrically it is a much “stronger” device: IDSS 24–60 mA and gfs 8–18 mS. In an original TIS88A circuit, that usually means:

• higher drain current unless source bias is changed,
• a different optimum source impedance,
• more risk of oscillation or overload if the layout is marginal,
• and a greater chance you will need to retouch alignment or neutralization. (media.digikey.com)

So, in engineering terms:

• Closest replacement: PN4416 / 2N4416
• Best still-active high-gm modern alternative: MMBFJ310LT1G / SMMBFJ310LT3G
• Not recommended as a “modern” choice anymore: 2N5486, mainly because lifecycle status is poor. (mouser.com)

---

Current information and trends

As of March 17, 2026, the market for small RF JFETs is much thinner than it was historically. Current distributor/manufacturer information shows:

• onsemi 2N5486G: listed as Obsolete / no longer manufactured by DigiKey. (digikey.com)
• legacy onsemi PN4416: also listed by DigiKey as Obsolete. (digikey.com)
• onsemi MMBFJ310LT1G: listed by DigiKey as Active. (digikey.com)
• InterFET 2N4416 / PN4416 / SMP4416 family: currently listed in InterFET documentation, including TO-72, TO-92, and SOT-23 options, and Mouser shows the family through authorized distribution. (mouser.com)
• AEM/Central 2N4416: shown as Active on the AEM product page. (aeminc.com)

The practical trend is clear: true RF JFETs still exist, but you increasingly buy them from specialty analog/JFET vendors rather than from the large mainstream transistor catalogues. (mouser.com)

---

Supporting explanations and details

A useful way to think about this is:

• The TIS88A is a tuned-circuit RF part.
• The PN4416 is another tuned-circuit RF part with almost the same “personality.”
• The J310 is a stronger, faster athlete, but not the same body size. It may perform very well, but you will probably need to tailor the circuit around it. (datasheet4u.com)

If your goal is repair with minimum disturbance, use PN4416. If your goal is modernize and you do not mind reworking bias/package, use MMBFJ310. (mouser.com)

---

Ethical and legal aspects

From a practical reliability standpoint, it is better to prefer current listed parts from authorized channels over random NOS marketplace stock. That is especially relevant here because some once-common alternatives, such as 2N5486G and older PN4416 listings from onsemi, are now obsolete. (digikey.com)

Also observe normal RF repair safety:

• ESD handling matters with JFET gates.
• A mistuned or oscillating front end can give misleading “works on the bench” results.
• Final verification should include sensitivity, strong-signal behavior, and dial-tracking/alignment checks.

---

Practical guidelines

• Best first choice: install InterFET PN4416 for TO-92 repairs. (mouser.com)
• Second choice: use MMBFJ310LT1G / SMMBFJ310LT3G only if you accept rebiasing and an adapter board. (digikey.com)
• Check pinout carefully. InterFET publishes dedicated TO-92 and SOT-23 pinouts for the 2N4416 family; do not assume they match your original device without tracing the board. (interfet.com)
• Measure drain current after replacement. If you use PN4416, the original bias network is more likely to land close to the correct operating point because the \(I_{DSS}\) and \(g_m\) class matches the TIS88A closely. (datasheet4u.com)
• Expect alignment touch-up. Even a close replacement changes parasitics slightly. The TIS88A lists 4.5 pF / 1.0 pF input/reverse-transfer capacitance, while the 2N4416 family lists 4.0 pF / 0.8 pF. (datasheet4u.com)

---

Possible disclaimers or additional notes

If your tuner front end is not FM/VHF but some unusual variant, or if the TIS88A is used in a mixer/oscillator rather than a simple RF amplifier, the “best” substitute can change slightly. In that case the exact circuit topology, supply voltage, source resistor value, and whether AGC is applied to the FET all matter.

---

Suggestions for further research

If you can provide the schematic or at least:

• supply voltage,
• source resistor value,
• drain load/tuned-circuit arrangement,
• and whether the stage is RF amp, self-oscillating mixer, or local oscillator,

then I can tell you whether PN4416, PN4416A, or MMBFJ310 is the better choice and whether the source resistor should be changed.

---

Brief summary

For a true modern replacement of the TIS88A in a tuner front end, my recommendation is:

1. InterFET PN4416 — best overall and closest electrical/RF match. (datasheet4u.com)
2. InterFET 2N4416 / SMP4416 — same device family in other packages. (mouser.com)
3. onsemi MMBFJ310LT1G / SMMBFJ310LT3G — good active modern option, but not a drop-in bias match. (digikey.com)

If you want the shortest possible answer: use PN4416 first; use J310 only if you are prepared to rebias.

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.