# A7986ATR

**STMicroelectronics** · DC-DC Converters · SOIC-8

A7986ATR from STMicroelectronics, in a SOIC-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 | OUT | power_out | Regulator output; the output DC voltage is limited to -0.3 V to VCC per the absolute maximum ratings. |
| 2 | SYNCH | bidirectional | Master/slave synchronization pin: left floating it outputs a signal half a period out of phase with power turn-on, and when driven by an external signal above the internal frequency the device synchronizes to it with zero phase shift; its analog pin voltage is limited to -0.3 V to 4 V. |
| 3 | EN | input | Active-high enable: the device is ON above 1.2 V and OFF below 0.3 V, with the pin rated -0.3 V to VCC. |
| 4 | COMP | output | Error amplifier output used for loop frequency compensation; its analog pin voltage is limited to -0.3 V to 4 V. |
| 5 | FB | input | Feedback input: connecting VOUT directly regulates the output at 0.6 V (VFB 0.588 V to 0.612 V), and higher voltages require an external resistor divider from VOUT; the feedback voltage is rated -0.3 V to 1.5 V. |
| 6 | FSW | passive | Switching frequency set pin: an external resistor to ground raises the frequency above the 250 kHz free-running value (up to 1 MHz with RFSW = 33 kΩ), and leaving it floating gives 250 kHz; the analog pin voltage is limited to -0.3 V to 4 V. |
| 7 | GND | power_in | Ground reference for the device. |
| 8 | VCC | power_in | Unregulated DC input voltage with an operating range of 4.5 V to 38 V and an absolute maximum of 45 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SOIC-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `A7986ATR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `a7986atr-etched.step` / `a7986atr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `a7986atr.step` / `a7986atr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [STMicroelectronics datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603165528047296512) (42 pp, sha256 `a76d19b8a435a683`, retrieved 2026-10-08, 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/a7986atr-datasheet.pdf)