LM4890S from IDCHIP, in a MSOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	SHUTDOWN	input	Active-low shutdown control. Drive high (VIH ≥ 1.2V) for normal operation; drive low (VIL ≤ 0.4V) to place the amplifier into low-power shutdown mode (ISD ≈ 0.1µA typ).
2	BYPASS	passive	Internal common-mode (half-supply) bias bypass node. Connect a bypass capacitor (typically 1µF) from this pin to GND to filter the internal mid-rail reference and improve PSRR / pop suppression.
3	+IN	input	Non-inverting analog audio input of the internal amplifier A1. Typically AC-referenced to the BYPASS mid-rail in the standard application.
4	-IN	input	Inverting analog audio input. Sets the closed-loop gain via external RIN (typ 20kΩ) and Rf (typ 68kΩ); combines with CIN to form the input high-pass filter fC = 1/(2π·RIN·CIN).
5	VO1	output	BTL speaker output (negative/inverting side of the bridge, VOUT-). Connect one terminal of the 8Ω speaker load between VO1 (pin 5) and VO2 (pin 8). No output coupling capacitor required.
6	VDD	power_in	Positive supply input, 2.2V to 5.5V operating range (5.5V absolute max). Decouple locally with CS (typ 1µF) to GND.
7	GND	power_in	Ground / supply return. All voltages in the datasheet are referenced to this pin.
8	VO2	output	BTL speaker output (positive/non-inverting side of the bridge, VOUT+). Connect the other terminal of the 8Ω speaker load here. No output coupling capacitor required.

Key specifications

Parameter	Value
Manufacturer	IDCHIP
Package	MSOP-8
Category	Op-amp/Cmp
Pins	8

Ordering variants

Same part, different packaging or reel option.

LM4890SS

CAD (KiCad official)

Symbol: LM4890S
Footprint: Package_SO:MSOP-8_3x3mm_P0.65mm
3D model: MSOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`lm4890s.step`	123 KB	You want the bare part, or you mark your own boards.
`lm4890s-etched.step`	1.8 MB	You want the part with `LM4890S` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 444 faces against 147 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: IDCHIP datasheet (8 pp, sha256 a83b352f78b378f3, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF