MC34119G-S08-R — 250mW Low-Power Speakerphone Audio Amplifier (SOP-8) from UTC

What Are the Technical Specifications of MC34119G-S08-R?

Key numbers that matter: the 2.0V floor is the headline spec. Two nickel-metal-hydride cells (2.4V) will run this amp — nothing else in this class goes that low.

The 52dB PSRR figure only exists if you fit the filter caps: 1µF on FC1, 5µF on FC2. Skip them and the hum comes back.

When Should You Use (and NOT Use) the MC34119G-S08-R?

✅ Use MC34119G-S08-R when:

• Speakerphone / hands-free audio in a voice product. The 300Hz–3.4kHz voice band is where this amp lives; the internal gain structure is tuned for it.
• Low-voltage battery rails (2–3.3V). Two cells, a Li-ion at end of charge, or a 3.3V rail — the 2.0V minimum covers all of them with headroom.
• Direct speaker drive. VO1 and VO2 swing 180° out of phase, so the speaker sees double the single-ended swing — and needs no coupling capacitor between amp and speaker.
• Mute or power-down control from a GPIO. Pull Pin 1 above 2.0V and the amp drops to 65µA with >70dB of attenuation, in under 2µs.
• MC34119-family drop-in. UTC, Motorola/NXP, and clone versions share the same 8-pin layout in DIP, SOP, and TSSOP — swap packages without a board change.

❌ Don't use MC34119G-S08-R when:

• You need more than ~250mW. This is a voice-band handset amp, not a music driver. For a few watts, step up to TDA2822M (1.4W×2) or a class-D amp.
• Full-bandwidth music reproduction. Specs are optimized for 300Hz–3.4kHz. A hi-fi headphone or speaker amp (LM386-class, or a class-D) keeps the 20Hz–20kHz range cleaner.
• 4Ω speakers. Minimum load is 8Ω. Below that, the output current limit (±250mA) clips and the die runs hot.
• Stereo output. The MC34119 is mono. For stereo voice or audio, two parts or a stereo amp like TDA2822.

What Are the Alternatives to MC34119G-S08-R?

The MC34119 vs LM386 decision in one line: battery-powered voice with a mute pin → MC34119; bench-top audio with headroom to spare → LM386. The differential output is the differentiator — on a 3.3V rail, the MC34119's effective swing is 6.6V pk-pk against the LM386's single-ended ~3V.

What Are the Typical Applications of MC34119G-S08-R?

Speakerphone / hands-free in landline and cordless phones: the amp's original design target. The 300Hz–3.4kHz gain shaping and the differential output make a clean path from line audio to the internal speaker; the CD pin drops the amp out of the path when the handset lifts.

Low-voltage intercom and doorphone modules: a 2–3V rail from two cells or a small supply is common in door intercoms. The 2.0V minimum runs off a nearly-dead battery pair, and the 65µA mute state keeps idle drain invisible.

Push-to-talk (PTT) radios and walkie-talkie audio: voice-band gain up to 46dB from a small speaker, plus instant mute via the CD pin — the keying circuit simply pulls CD high while the transmitter is off.

Battery-powered voice products with GPIO mute: toys, medical voice prompts, and emergency call devices. The CD pin accepts a 3.3V logic signal directly (logic high ≥2.0V mutes), so a MCU controls audio without extra switching components.

Why Buy MC34119G-S08-R from ICMASS?

Every lot tested for mute behavior and THD. We batch-test the CD-pin threshold and output distortion on MC34119Gs before they ship. Cloned parts from gray-market channels typically pass a DC test but mute with 10–20dB less attenuation — the handset "whispers" instead of going silent.

Cross-reference support for the whole family. Not sure whether your design wants MC34119, LM386, or TDA2822? Send us your supply voltage, speaker impedance, and mute requirements — we'll tell you which part the board actually needs.

BOM consolidation for phone and intercom builds. The same product usually carries a TL431 reference, small-signal transistors, an electret mic, and the MC34119. One shipment from Shenzhen covers the whole audio and control section.

Same-day dispatch, 5–10 days worldwide. Orders before 15:00 CST ship same day via DHL or FedEx. For volume orders, we source directly from the UTC production line.

Frequently Asked Questions About MC34119G-S08-R

Q1: My MC34119 output is very quiet — what's wrong?

A: Check the gain resistors first, then the bypass capacitor. Incorrect R_f/R_i values pin the closed-loop gain near 0dB. Fit a 100µF electrolytic across VCC near the chip, and ground the CD pin (pin 1) if it isn't driven. Every part in the datasheet example circuit is there for a reason.

Q2: Do I really need the FC2 capacitor if FC1 has one?

A: For line-powered or noisy supplies, yes — the 52dB figure assumes both. C1 (1µF on FC1) handles high-frequency ripple; C2 (5µF on FC2) dominates where mains hum lives. FC2 can be left open on a clean battery supply, but line-powered designs need it, connected to ground.

Q3: What happens if I leave the mute (CD) pin floating?

A: The chip stays enabled — floating reads as logic low — but it's a bad idea. An open input at ~90kΩ impedance picks up noise and can mute intermittently on its own. Tie pin 1 to GND when unused, or drive it cleanly: below 0.8V to enable, above 2.0V to mute. Stay out of the 0.8V–2.0V undefined band.

Q4: There's a hum/buzz on the speaker in my speakerphone — why?

A: Supply ripple is getting into the audio path — the FC1/FC2 filter caps are undersized or missing. The 52dB rejection assumes 1µF on FC1 and 5µF on FC2; without them, mains hum rides straight to the speaker. Line-powered handsets need more filtering than battery-powered ones.

Q5: Why is there a delay when the amp unmutes?

A: That's the design — turn-on takes 12–15ms, independent of your external parts. Mute turn-off is under 2µs; unmute ramps over 12–15ms. FC1/FC2 also charge through internal 50kΩ/125kΩ resistors, so cold start is ~60% slower at 3.0V. Normal behavior, not a fault.

Q6: Can I run the MC34119 from 3.3V?

A: Yes — the 2.0V minimum covers it, with less power available. The 250mW figure is specified at VCC=6V; at 3.3V the swing drops proportionally, so expect roughly a third to half the power into the same 32Ω speaker. Fine for a voice-band handset.

Q7: Do I need a coupling capacitor to the speaker?

A: No — that's the point of the differential outputs. VO1 and VO2 swing 180° out of phase, so the speaker connects directly between pins 5 and 8 with no DC blocking cap. The load sees twice the single-ended swing — how 250mW comes out of a 6V rail.

Q8: MC34119 vs LM386 — which should I use?

A: MC34119 for battery voice + mute control; LM386 for general bench-top audio. The MC34119 runs from 2.0V (LM386 needs 4V), mutes to 65µA via a logic pin, and drives the speaker differentially. The LM386 wins on familiarity and single-ended simplicity.

Q9: What's the maximum gain I can set?

A: 46dB in the voice band is the datasheet's recommended ceiling. The closed-loop gain is R_f/R_i on Amp #1, adjustable from below 0dB. Above 46dB, bandwidth rolls off inside the 300Hz–3.4kHz band and stability margin tightens. For a handset application, 20–40dB is the practical range.

Q10: MC34119 vs TDA2822 — which one for my speakerphone?

A: MC34119 if the supply is 2–3.3V and you need mute; TDA2822 for a 5V+ rail and real volume. Both are 8-pin and drive a speaker directly — the 2.0V floor suits battery voice, the 1.4W per channel suits intercoms. See our TDA2822 comparison for the full look.