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Texas Instruments LM4938MHX — Logic ICs

LM4938MHX Class AB Audio Amp, 2.2W x 2 @ 3Ω, 28-HTSSOP

MPNLM4938MHX
End of Life

National Semiconductor LM4938MHX Boomer® Class AB, 2-Channel (Stereo) with Stereo Headphones, 2.2W x 2 @ 3Ohm, 2.7V ~ 5.5V, Surface Mount 28-TSSOP (0.173", 4.40mm Width) Exposed Pad, -20°C ~ 85°C.

$0.59Ref. price · indicative, final on quote
Texas Instruments LM4938MHX datasheet (PDF)
Packaging28-TSSOP (0.173", 4.40mm Width) Exposed Pad
RoHSRoHS non-compliant
SeriesBoomer®
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

LM4938MHX specifications
ParameterValue
TypeClass AB
SeriesBoomer®
Output type2-Channel (Stereo) with Stereo Headphones
MountingSurface Mount
Supply voltage2.7V ~ 5.5V
Max output power x channels @ load2.2W x 2 @ 3Ohm
Operating temperature-20°C ~ 85°C (TA)
PackageBulk
Case28-TSSOP (0.173\", 4.40mm Width) Exposed Pad

Product details

The National Semiconductor LM4938MHX is a Boomer® series Class AB audio amplifier delivering 2.2W x 2 into a 3Ω load from a 5V supply. That 2.2W per channel figure is the headline rating that drives the speaker selection and the thermal design. The supply range of 2.7V to 5.5V means it runs comfortably from a single Li-ion cell or a 3.3V/5V regulated rail.

The RoHS compliance flag shows non-compliant — if your BOM requires RoHS-10/10, this part will not clear that gate, so check your exemption or plan for a lead-free alternate.

The 28-TSSOP with exposed pad (HTSSOP) helps pull heat out of the die; a layout without the pad soldered to a copper pour will derate the output power well below the 2.2W figure.

Frequently asked questions

What is the difference between LM4938MHX and LM4938MH?

The LM4938MHX is the tape-and-reel / bulk-packaged variant of the LM4938MH. The die and electrical specifications are identical — the suffix difference is purely a packaging and shipping format distinction. The LM4938MHX ships in bulk; the LM4938MH typically ships in tube. Both are the same 28-HTSSOP part.

Does LM4938MHX require an external heatsink?

The 28-HTSSOP package includes an exposed pad that serves as the primary thermal path. With the pad properly soldered to a copper plane and a via stitch, the part can deliver 2.2W per channel without an add-on heatsink in typical indoor environments. Without that pad connection, output power must be derated significantly.