# BD9G101G-TR

**ROHM** · DC-DC Converters · SOT-23-6

BD9G101G-TR from ROHM, in a SOT-23-6. 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 supply for the floating high-side power NMOS driver. Connect a bypass capacitor between BST and LX for bootstrap operation. Max BST-to-GND 50V; max BST-to-LX 7V. |
| 2 | GND | power_in | Ground return. Should be connected as close as possible to the output capacitor ground to avoid the high-current switching path. |
| 3 | FB | input | Voltage feedback pin; error-amp input. The DC/DC regulates FB to 0.75V (±1.5% at 25°C). Set output voltage with an external resistor divider from VOUT to FB. Max FB voltage 7V. |
| 4 | EN | input | Enable input. DC/DC starts when EN ≥ 2.0V; shuts down when EN is open or ≤ 0.8V. Internal pull-down of about 550kΩ to GND. Max EN voltage 45V. |
| 5 | VCC | power_in | Input supply pin, 6V to 42V operating range (45V absolute max). Should be bypassed with a capacitor located as close to the pin as possible. |
| 6 | LX | output | Power NMOS switch node output. Connect to the Schottky freewheeling diode and inductor as close to the pin as possible. Max LX voltage 45V; typical switch current limit 1.2A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ROHM |
| Package | SOT-23-6 |
| Category | PMIC |
| Pins | 6 |

## Ordering variants

- `BD9G101G-TR`

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Stand-by Current | Ist |  | 0 | 5 | µA | VEN=0V | 4 |
| Operating Current | Icc |  | 0.7 | 1.2 | mA | FB=1.2V | 4 |
| UVLO Threshold Voltage | Vuv | 5.1 | 5.4 | 5.7 | V |  | 4 |
| UVLO Hysteresis width | Vuvhy |  | 200 | 300 | mV |  | 4 |
| Switching Frequency | fosc | 1.3 | 1.5 | 1.7 | MHz |  | 4 |
| Max Duty Cycle | Dmax | 85 |  |  | % |  | 4 |
| FB Pin Reference Voltage | VFBN | 0.739 | 0.75 | 0.761 | V | Ta=25℃ | 4 |
| FB Pin Reference Voltage | VFBA | 0.735 | 0.75 | 0.765 | V | Ta=-25~105℃ | 4 |
| FB Pin Bias Current | IFB | -100 | 0 | 100 | nA | VFB=2.0V | 4 |
| Soft-Start Time | Tsoft | 1.2 | 4 |  | ms |  | 4 |
| Switch Current Limit | Iocp | 0.85 | 1.2 |  | A |  | 4 |
| EN Threshold Voltage ON | VENON | 2 |  |  | V |  | 4 |
| EN Threshold Voltage OFF | VENOFF | -0.3 |  | 0.8 | V |  | 4 |
| EN Input Bias Current | REN | 2.7 | 5.5 | 11 | µA | VEN=3V | 4 |
| Input Voltage | VCC | 6 |  | 42 | V |  | 5 |
| Output Voltage | VOUT | 1 |  |  | V | Restricted by minimum on pulse typ. 100nsec (*3); upper limit VCC×0.7 restricted by max duty, Ron and BST-UVLO (*4) | 5 |
| Output Current | IOUT |  |  | 500 | mA |  | 5 |
| Input Voltage | VCC |  |  | 45 | V |  | 4 |
| Maximum input current | Imax |  |  | 1 | A |  | 4 |
| BST to GND | VBST |  |  | 50 | V |  | 4 |
| BST to LX | ⊿VBST |  |  | 7 | V |  | 4 |
| EN | VEN |  |  | 45 | V |  | 4 |
| Lx | VLx |  |  | 45 | V |  | 4 |
| FB | VFB |  |  | 7 | V |  | 4 |
| Power Dissipation | Pd |  |  | 0.675 | W | During mounting of 70×70×1.6t mm 1layer board. Reduce by 5.4mW for every 1℃ increase. (Above 25℃) | 4 |
| Operating Temperature | Topr | -40 |  | 105 | ℃ |  | 4 |
| Storage Temperature | Tstg | -55 |  | 150 | ℃ |  | 4 |
| Junction Temperature | Tjmax |  |  | 150 | ℃ |  | 4 |

## CAD (KiCad official)

- Symbol: `BD9G101G-TR`
- Footprint: `Package_TO_SOT_SMD:SOT-23-6`
- 3D model: SOT-23-6 (KiCad packages3D, STEP)
- 3D model files: `bd9g101g-tr-etched.step` / `bd9g101g-tr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bd9g101g-tr.step` / `bd9g101g-tr.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`bd9g101g-tr.step`](bd9g101g-tr.step) | 97 KB | You want the bare part, or you mark your own boards. |
| [`bd9g101g-tr-etched.step`](bd9g101g-tr-etched.step) | 2.0 MB | You want the part with `BD9G101G-TR` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 501 faces against 117 in the bare model. It
survives export, section views, and rendering in any CAD tool, and it drops straight
into KiCad or Fusion with no extra setup.

## Provenance

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

- **Datasheet:** [ROHM datasheet](docs/bd9g101g-tr-datasheet.pdf) (26 pp, sha256 `8a1aa401940eac2d`, retrieved 2026-08-17, tier: manufacturer)
- **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/bd9g101g-tr-datasheet.pdf)