# VIPER115LSTR

**STMicroelectronics** · AC-DC Controllers And Regulators · SOP-10

VIPER115LSTR from STMicroelectronics, in a SOP-10. 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 | GND | power_in | Ground and source of the internal MOSFET and return of the device bias current; all bias-component grounds must be tied to a trace going to this pin, separate from the pulsed current return. |
| 2 | VCC | power_in | Controller supply (4.5 V to 30 V operating range) needing an external storage capacitor to GND, also fed by the internal HV current source for startup charging, with a 0.1 µF typ. bypass capacitor recommended close to the IC. |
| 3 | DIS | input | Disable input: if voltage exceeds VDIS_th (1.2 V typ.) for more than tDEB (1 ms typ.) the PWM is disabled for tDIS_RESTART (500 ms typ.) in auto-restart, used for input/output overvoltage protection via a divider, and must be soldered to GND if unused. |
| 4 | FB | input | Direct feedback, inverting input of the internal transconductance E/A referenced to 1.2 V with respect to GND, fed by the output divider (or VCC divider for primary regulation), and the E/A is disabled by soldering FB to GND. |
| 5 | COMP | output | Compensation, output of the internal E/A, with a compensation network to GND for loop stability, or driven directly by the optocoupler (E/A disabled) in secondary feedback to set the DRAIN peak current setpoint. |
| 6 | DRAIN | passive | MOSFET drain (800 V max), internal HV current source sinks current from it to charge VCC at startup, mechanically connected to the internal metal pad, with copper area required under these pins for heat dissipation. |
| 7 | DRAIN | passive | MOSFET drain (800 V max), internal HV current source sinks current from it to charge VCC at startup, mechanically connected to the internal metal pad, with copper area required under these pins for heat dissipation. |
| 8 | DRAIN | passive | MOSFET drain (800 V max), internal HV current source sinks current from it to charge VCC at startup, mechanically connected to the internal metal pad, with copper area required under these pins for heat dissipation. |
| 9 | DRAIN | passive | MOSFET drain (800 V max), internal HV current source sinks current from it to charge VCC at startup, mechanically connected to the internal metal pad, with copper area required under these pins for heat dissipation. |
| 10 | DRAIN | passive | MOSFET drain (800 V max), internal HV current source sinks current from it to charge VCC at startup, mechanically connected to the internal metal pad, with copper area required under these pins for heat dissipation. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SOP-10 |
| Category | Power Management (PMIC) |
| Pins | 10 |

## CAD (KiCad official)

- Symbol: `VIPER115LSTR`
- Footprint: `Package_SO:SOIC-10_3.9x4.9mm_P1mm`
- 3D model: SOP-10, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 1.75 mm nominal SOIC height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files: `viper115lstr-etched.step` / `viper115lstr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `viper115lstr.step` / `viper115lstr.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/8603182565377253376) (37 pp, sha256 `c43ec45622596607`, retrieved 2026-10-10, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/viper115lstr-datasheet.pdf)