# GBI1633SMAR

**GOSEMICON** · DC-DC Converters · ESOP-8

GBI1633SMAR from GOSEMICON, 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 | BOOT | input | Power supply for the high-side power MOSFET gate driver; must connect a 0.1uF or greater ceramic capacitor between the BOOT and SW pins. |
| 2 | VIN | power_in | Power supply input for the device (4.5V to 60V operating range), which must be locally bypassed. |
| 3 | EN | input | Enable logic input that supports voltages up to the VIN supply, with precision thresholds of 1.21V rising and 1.05V falling; floating the pin enables the device. |
| 4 | RT | input | Resistor timing pin that sets the switching frequency through a resistor to GND, and must not be left floating or shorted to GND. |
| 5 | FB | input | Buck converter feedback sense input; a resistor divider from VOUT to FB and from FB to GND sets the output, regulating FB to the internal 0.75V reference. |
| 6 | SS | input | Soft-start time pin; a capacitor to GND sets the soft-start time, and the pin may be left floating for a default soft-start time of about 5ms. |
| 7 | GND | power_in | Ground reference for the device. |
| 8 | SW | output | Switching node of the buck converter, rated up to 65V (SW to GND) per the absolute maximum ratings. |
| 9 | Thermal Pad | power_in | Exposed thermal pad that must be grounded in the PCB layout. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | GOSEMICON |
| Package | ESOP-8 |
| Category | Power Management (PMIC) |
| 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 |
|---|---|---|---|---|---|---|---|
| Input voltage VIN, EN to GND |  | -0.3 |  | 65 | V |  | 3 |
| FB to GND |  | -0.3 |  | 6.5 | V |  | 3 |
| SS to GND |  | -0.3 |  | 6.5 | V |  | 3 |
| RT to GND |  | -0.3 |  | 6.5 | V |  | 3 |
| SW to GND |  | -0.6 |  | 65 | V |  | 3 |
| SW to GND (20ns transient) |  | -3 |  | 65 | V | 20ns transient | 3 |
| BOOT to SW |  |  |  | 6.5 | V |  | 3 |
| Junction temperature | TJ | -40 |  | 150 | °C |  | 3 |
| Storage temperature | TSTG | -65 |  | 150 | °C |  | 3 |
| VIN Supply voltage range | VIN | 4.5 |  | 60 | V |  | 3 |
| BOOT to SW |  | 0 |  | 6 | V |  | 3 |
| FB, EN, PG |  | 0 |  | 6 | V |  | 3 |
| EN | EN | 0 |  | 60 | V |  | 3 |
| Switching frequency range at RT mode | fSW | 200 |  | 2000 | kHz |  | 3 |
| Operating junction temperature | TJ | -40 |  | 125 | °C |  | 3 |
| Junction to ambient thermal resistance (eSOP-8L) | RθJA |  | 42.5 |  | °C/W |  | 4 |
| Junction to case thermal resistance (eSOP-8L) | RθJC |  | 56.1 |  | °C/W |  | 4 |
| Junction to board characterization parameter (eSOP-8L) | ψJB |  | 25.4 |  | °C/W |  | 4 |
| Junction to top characterization parameter (eSOP-8L) | ψJT |  | 10 |  | °C/W |  | 4 |
| Operating input voltage | VIN | 4.5 |  | 60 | V |  | 4 |
| Input UVLO (VIN rising) | VIN_UVLO |  | 4.2 | 4.4 | V | VIN rising | 4 |
| Input UVLO hysteresis |  |  | 350 |  | mV |  | 4 |
| Shutdown current | ISHDN |  | 1 |  | uA | EN=0, No load, 4.5V≤VIN≤60V | 4 |
| Quiescent current | IQ |  | 100 |  | uA | EN=floating, No load, No switch, 4.5V≤VIN≤60V, BOOT-SW=5V | 4 |
| Enable high threshold | VEN_H | 1.17 | 1.21 | 1.25 | V |  | 4 |
| Enable low threshold | VEN_L |  | 1.05 |  | V |  | 4 |
| Feedback voltage | VFB | 0.742 | 0.75 | 0.758 | V |  | 4 |
| High side FET on-resistance | RDSON_H | 100 | 150 | 235 | mΩ |  | 4 |
| Switching frequency | fSW | 410 | 470 | 520 | KHz | RT=50k | 4 |
| Maximum switching frequency |  |  | 2 |  | MHz |  | 4 |
| Minimum on-time | tON_MIN |  | 100 |  | ns |  | 4 |
| Maximum duty cycle | DMAX |  | 95 |  | % | fSW=500kHz | 4 |
| Internal soft-start time | tSS | 1.8 | 5 | 7.8 | ms | SS pin floating | 4 |
| Soft start current | ISS |  | 4 |  | uA |  | 4 |
| HSD peak current limit | ILIM_HSD | 4.45 | 4.75 | 5.05 | A | VIN=24V | 5 |
| Thermal shutdown threshold | TSD |  | 170 |  | °C |  | 5 |
| Thermal shutdown hysteresis |  |  | 30 |  | °C |  | 5 |
| Output over voltage protection rising | VOVP_H |  | 108 |  | % |  | 5 |
| Output over voltage protection falling | VOVP_L |  | 103 |  | % |  | 5 |
| Output under voltage protection falling | VUVP_L |  | 92 |  | % |  | 5 |
| Output under voltage protection rising | VUVP_H |  | 97 |  | % |  | 5 |

## CAD (KiCad official)

- Symbol: `GBI1633SMAR`
- Footprint: `Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.41x3.3mm`
- 3D model: ESOP-8 (KiCad packages3D, STEP)
- 3D model files: `gbi1633smar-etched.step` / `gbi1633smar-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `gbi1633smar.step` / `gbi1633smar.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [GOSEMICON datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8756313141577953280) (19 pp, sha256 `3c112b7acfbd9ef8`, retrieved 2026-10-18, 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/gbi1633smar-datasheet.pdf)