# RY3831

**RYCHIP** · DC-DC Converters · ESOP-8

RY3831 from RYCHIP, in a ESOP-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 | BST | passive | Bootstrap pin. A capacitor connected between SW and BST forms a floating supply that powers the high-side MOSFET gate driver. |
| 2 | VIN | power_in | Power supply input pin. Accepts 4V to 18V (absolute max 21V). Bypass close to the pin with a ceramic input capacitor. |
| 3 | SW | power_out | Switching node. Connects the internal high-side and low-side MOSFETs to the external inductor. Voltage swings between GND and VIN at 500kHz. |
| 4 | GND | power_in | Ground pin. Tie to the exposed pad and to a large copper area for thermal dissipation. |
| 5 | FB | input | Feedback input for the adjustable output. Connect to the center tap of an external resistor divider from VOUT to GND. Regulated to VFB = 0.923V typical (0.905V - 0.940V). |
| 6 | NC | unconnected | No internal connection. Leave floating or tie to GND per PCB layout convenience. |
| 7 | EN | input | Enable input. Drive logic-high to enable the regulator; drive logic-low to disable and enter micro-power shutdown. Absolute max 21V. |
| 8 | NC | unconnected | No internal connection. Leave floating or tie to GND per PCB layout convenience. |
| 9 | EPAD | power_in | Exposed thermal pad on the package bottom. Electrically GND. Must be soldered to a large ground copper pour for heat dissipation and to meet the 50°C/W θJA rating. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | RYCHIP |
| Package | ESOP-8 |
| Category | PMIC |
| Pins | 9 |

## CAD (KiCad official)

- Symbol: `RY3831`
- Footprint: `Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm`
- 3D model: ESOP-8 (KiCad packages3D, STEP)
- 3D model files: `ry3831-etched.step` / `ry3831-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ry3831.step` / `ry3831.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [RYCHIP datasheet](docs/ry3831-datasheet.pdf) (7 pp, sha256 `1febf33afacecd6b`, 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](docs/ry3831-datasheet.pdf)