Loads on click. Unloads only if this page sits in the background.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads on click. Unloads only if this page sits in the background.

PCB Footprint

Open full view ↗
Loads on click. Unloads only if this page sits in the background.
Loads on click. Unloads only if this page sits in the background.
Download PDF
Contents

README

markdown

NS4251

Shenzhen Nsiway Tech · Audio Amplifiers · QFN-16-EP(3x3)

NS4251 from Shenzhen Nsiway Tech, in a QFN-16-EP(3x3). 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 VOPB output Right channel positive audio output for bridged speaker mode or right headphone output in single-ended mode.
2 HP-IN input Headphone mode control input with VIL=0.4V selecting bridged output and VIH=1.4V selecting single-ended headphone output.
3 SD input Shutdown control input (active high) with shutdown current of 1-10µA when enabled; design with pull-up to ensure shutdown during floating or high-impedance conditions.
4 VOPA output Left channel positive audio output for bridged speaker mode or left headphone output in single-ended mode.
5 GND power_in Power ground reference.
6 VDD power_in Power supply input rated 3.0V to 5.5V with bypass capacitor (10µF electrolytic
7 VONA output Left channel negative audio output providing signal return for bridged speaker output.
8 INNA input Left channel input signal (negative terminal) AC-coupled through capacitor Ci (0.1µF-0.39µF) and resistor Ri setting gain Av=240k/Rin.
9 GND power_in Power ground reference.
10 /3D input 3D surround stereo function control input (active low); low level enables 3D processing, high level disables it.
11 VREF power_in Reference voltage bypass pin requiring 1µF capacitor to ground for quiescent point stabilization and pop noise reduction.
12 AB/D input Class AB/D mode control input (cannot float); low level enables Class AB mode, high level enables Class D mode with 350kHz PWM frequency.
13 INNB input Right channel input signal (negative terminal) AC-coupled through capacitor Ci (0.1µF-0.39µF) and resistor Ri setting gain Av=240k/Rin.
14 VONB output Channel negative audio output (datasheet labels as left channel but naming convention suggests right channel B); provides signal return for output stage.
15 VDD power_in Power supply input rated 3.0V to 5.5V with bypass capacitor (10µF electrolytic
16 GND power_in Power ground reference.
17 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer Shenzhen Nsiway Tech
Package QFN-16-EP(3x3)
Category Amplifiers/Comparators
Pins 17

CAD (KiCad official)

  • Symbol: NS4251
  • Footprint: Package_DFN_QFN:QFN-16-1EP_3x3mm_P0.5mm_EP1.7x1.7mm
  • 3D model: QFN-16-EP(3x3) (KiCad packages3D, STEP)
  • 3D model files: ns4251-etched.step / ns4251-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); ns4251.step / ns4251.glb are the bare package body.

Provenance

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

  • Datasheet: Shenzhen Nsiway Tech datasheet (12 pp, sha256 eb0cd92f2be3a786, retrieved 2026-09-22, 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 0.2, primary claude-haiku-4-5-20251001 (text), consensus claude-sonnet-4-6 (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