# ETA9742E8A

**etasolution** · Battery Management · ESOP8

ETA9742E8A from etasolution, in a ESOP8. 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 | SW | bidirectional | Inductor connection: connect an inductor between SW and the regulator output. |
| 2 | LED | output | Battery level indication LED connection pin. |
| 3 | STAT | output | Charge status indication: STAT is pulled low while charging and is high impedance when charge is completed. |
| 4 | BST | output | Boost status indication: BST is pulled low in boost, pulled high when charging, and high impedance when entering no-load condition. |
| 5 | ISET | passive | Buck charging current setting pin: connect a resistor between this pin and analog ground to set the current level (Riset=56K gives 3A fast charge; Riset=91K gives 2A). |
| 6 | BAT | bidirectional | Battery pin: connect the battery to this pin, with a 10uF bypass capacitor. |
| 7 | OUT | bidirectional | Output pin: bypass with a 22uF or larger ceramic capacitor placed closely between this pin and GND. |
| 8 | PGND | power_in | Power ground pin. |
| 9 | AGND | power_in | Analog ground pin on the exposed pad; the datasheet says to connect the heat sink through vias to the GND plane on the backside. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | etasolution |
| Package | ESOP8 |
| Category | Power Management (PMIC) |
| Pins | 9 |

## CAD (KiCad official)

- Symbol: `ETA9742E8A`
- Footprint: `Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm`
- 3D model: ESOP8 (KiCad packages3D, STEP)
- 3D model files: `eta9742e8a-etched.step` / `eta9742e8a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `eta9742e8a.step` / `eta9742e8a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [etasolution datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590905353741946880) (5 pp, sha256 `9311e782af8c1e36`, retrieved 2026-10-09, tier: lcsc)
- **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/eta9742e8a-datasheet.pdf)