# AD2018

**IDCHIP(英锐芯)** · Audio Amplifiers · ESOP-8

AD2018 from IDCHIP(英锐芯), in a ESOP-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 | SD | input | Shutdown control: a logic high (VIH min 2.2 V) puts the amplifier into shutdown with outputs disconnected from the speaker, a logic low (VIL max 0.2 V) gives normal operation, and the pin must not be left floating. |
| 2 | BYP | output | Bias voltage output at VDD/2 that must be filtered with a CB capacitor, where 0.1 µF to 1 µF ceramic is the general range and 1 µF or larger is recommended to limit turn-on noise. |
| 3 | MODE | input | Operating mode control: a logic high (VIH min 2.2 V) selects Class-D operation, a logic low (VIL max 0.2 V) selects Class-AB, and the pin has an internal ~1.1 MΩ pull-up, so an MCU driving it in standby needs a 10 kΩ pull-down to GND. |
| 4 | IN | input | Single-ended analog audio input whose gain is set by the external input resistor Ri (AVD = 2×150 kΩ / (5 kΩ + Ri)) with an input coupling capacitor Ci forming the high-pass corner. |
| 5 | VO1 | output | Analog BTL output 1 that drives the speaker together with VO2; an optional LC filter may be added when the speaker trace exceeds about 100 mm. |
| 6 | VDD | power_in | Positive power supply with an operating range of 2.5 V to 5.0 V and an absolute maximum of 5.5 V, to be decoupled close to the pin. |
| 7 | GND | power_in | Power ground for the amplifier and its supply decoupling. |
| 8 | VO2 | output | Analog BTL output 2 that drives the speaker together with VO1 in the bridge-tied output stage. |
| 9 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | IDCHIP(英锐芯) |
| Package | ESOP-8 |
| Category | Amplifiers/Comparators |
| Pins | 9 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| 工作电压 (AB类) | VDD | 2.5 | 5 | 5.5 | V |  | 3 |
| 工作电压 (D类) | VDD | 2.5 | 5 | 5.5 | V |  | 4 |
| 关断电流 (AB类) | IOFF |  |  | 1 | μA | VDD=5V,VIN=0V | 3 |
| 工作电压 (推荐工作条件) | VDD | 2.5 |  | 5 | V |  | 3 |
| 工作温度 | Topr | -40 |  | 85 | ℃ |  | 3 |
| SD输入高电平 | VIH | 2.2 |  |  | V |  | 3 |
| MODE输入高电平 | VIH | 2.2 |  |  | V |  | 3 |
| SD输入低电平 | VIL |  |  | 0.2 | V |  | 3 |
| MODE输入低电平 | VIL |  |  | 0.2 | V |  | 3 |
| 电源电压 | VDD |  |  | 5.5 | V |  | 3 |
| 输入电压 (max = VDD+0.3V) | VIN | -0.3 |  |  | V |  | 3 |
| 人体模型静电电压 | HBM ESD |  |  | 2000 | V |  | 3 |
| 机器模型静电电压 | MM ESD |  |  | 250 | V |  | 3 |
| 储存温度 | TS | -65 |  | 150 | ℃ |  | 3 |
| 节点温度 | TJ |  |  | 150 | ℃ |  | 3 |
| 焊接温度 | TL |  |  | 260 | ℃ | 10秒内 | 3 |
| 热阻 结到壳 (ESOP) | θJC(ESOP) |  | 15 |  | oC/W |  | 3 |
| 热阻 结到环境 (ESOP) | θJA(ESOP) |  | 45 |  | oC/W |  | 3 |

## CAD (KiCad official)

- Symbol: `AD2018`
- Footprint: `Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.41x3.3mm`
- 3D model: ESOP-8 (KiCad packages3D, STEP)
- 3D model files: `ad2018-etched.step` / `ad2018-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ad2018.step` / `ad2018.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [IDCHIP(英锐芯) datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8604433290065690624) (8 pp, sha256 `4b5f89c28434cfa7`, retrieved 2026-10-25, 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/ad2018-datasheet.pdf)