# LM4871BM

**HGSEMI** · Audio Amplifiers · SOP-8

LM4871BM from HGSEMI, in a SOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | SHUTDOWN | input | Active-high shutdown control that disconnects the amplifier bias when driven high; it must be tied to VDD to shut down or to GND to enable the amplifier and must not be left floating. |
| 2 | BYPASS | output | Internal bias voltage node that requires a bypass capacitor CB, typically 0.1 µF, with the value chosen for low-frequency THD+N, system cost and size. |
| 3 | +IN | input | Non-inverting analog audio input of the amplifier. |
| 4 | -IN | input | Inverting analog audio input which, together with feedback resistor Rf and input resistor Ri, sets the closed-loop gain with AVD = 2(Rf/Ri) in bridge mode. |
| 5 | VO1 | output | Negative analog output of the bridge-tied load driver. |
| 6 | VDD | power_in | Power supply pin with a recommended operating range of 2.0 V to 5.0 V and an absolute maximum operating voltage of 6.0 V. |
| 7 | GND | power_in | Ground reference pin for the device. |
| 8 | VO2 | output | Positive analog output of the bridge-tied load driver; in single-ended use it is connected as a pseudo-load with a resistor and capacitor for stability. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | HGSEMI |
| Package | SOP-8 |
| Category | Amplifiers/Comparators |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `LM4871BM`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `lm4871bm-etched.step` / `lm4871bm-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm4871bm.step` / `lm4871bm.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [HGSEMI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8604440517782347776) (13 pp, sha256 `479d1184e9fd9d02`, retrieved 2026-10-12, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm4871bm-datasheet.pdf)