component
BD9876AEFJ-E2
Public Made by Adomby adom
ROHM Semicon DC-DC Converters, SOIC-8-EP. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
Open in new tab ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.
Symbol & Footprint
Schematic Symbol
Open full view ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
PCB Footprint
Open full view ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
Datasheet
Open in new tab ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
README
markdownBD9876AEFJ-E2
ROHM Semicon · DC-DC Converters · SOIC-8-EP
BD9876AEFJ-E2 from ROHM Semicon, in a SOIC-8-EP. 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 | Lx | output | Terminal for the inductor, connecting the internal Nch FET switch node to the external coil. |
| 2 | GND | power_in | Ground pin. |
| 3 | VC | output | Error amplifier output, where external C and R are connected to GND as phase compensation elements. |
| 4 | FB | input | Inverting node of the transconductance error amplifier, with internal standard voltage of 1.0V. |
| 5 | SYNC | input | Input pin for an external square-wave clock to synchronize the oscillator, with High level above 2V, Low level below 0.8V, and a synchronization range of 200kHz to 500kHz. |
| 6 | EN | input | Stand-by ON/OFF pin, where a voltage of 2.0V or more turns the IC on and open or 0V turns it off. |
| 7 | BST | power_in | Voltage supply pin for the high-side FET driver. |
| 8 | VCC | power_in | Voltage input pin; the input supply range is 7V to 42V. |
| 9 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | ROHM Semicon |
| Package | SOIC-8-EP |
| Category | Power Management ICs |
| 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 |
|---|---|---|---|---|---|---|---|
| VCC-GND Supply Voltage | VCC | 45 | V | 4 | |||
| BST-GND Voltage | VBST | 50 | V | 4 | |||
| BST-Lx Voltage | ⊿VBST | 7 | V | 4 | |||
| EN-GND Voltage | VEN | 45 | V | 4 | |||
| Lx-GND Voltage | VLX | 45 | V | 4 | |||
| FB-GND Voltage | VFB | 7 | V | 4 | |||
| VC-GND Voltage | VC | 7 | V | 4 | |||
| SYNC-GND Voltage | SYNC | 7 | V | 4 | |||
| High-side FET Drain Current | IDH | 3.5 | A | 4 | |||
| Power Dissipation | Pd | 3.76 | W | During mounting of 70×70×1.6t mm 4layer board (Copper area: 70mm×70mm); reduce by 30.08mW per °C above 25°C | 4 | ||
| Operating Temperature | Topr | -40 | 105 | ℃ | 4 | ||
| Storage Temperature | Tstg | -55 | 150 | ℃ | 4 | ||
| Junction Temperature | Tjmax | 150 | ℃ | 4 | |||
| Stand-by current of VCC | Ist | 0 | 10 | µA | VEN=0V | 4 | |
| Circuit current of VCC | Icc | 1 | 2 | mA | FB=1.2V | 4 | |
| UVLO Detect Voltage | Vuv | 6.1 | 6.4 | 6.7 | V | 4 | |
| UVLO Hysteresis width | Vuvhy | 200 | 300 | mV | 4 | ||
| Oscillating frequency | fosc | 270 | 300 | 330 | kHz | 4 | |
| Max Duty Cycle | Dmax | 85 | 91 | 97 | % | 4 | |
| FB threshold voltage | VFB | 0.99 | 1 | 1.01 | V | 4 | |
| Input bias current | IFB | -1 | 0 | 1 | µA | VFB=0V | 4 |
| Error amplifier DC gain | AVEA | 700 | 7000 | 70000 | V/V | 4 | |
| Trans Conductance | GEA | 110 | 220 | 440 | µA/V | IVC=±10µA, VC=1.5V | 4 |
| Soft Start Time | Tsoft | 7 | 10 | 13 | ms | 4 | |
| VC to switch current transconductance | GCS | 5 | 10 | 20 | A/V | 4 | |
| Lx NMOS ON resistance | RonH | 200 | 340 | mΩ | 4 | ||
| Lx pre-charge NMOS ON resistance | RonL | 10 | 17 | Ω | 4 | ||
| Over Current Detect Current | Iocp | 3.5 | 6 | A | 5 | ||
| EN Pin Control voltage ON | VENON | 2 | V | 5 | |||
| EN Pin Control voltage OFF | VENOFF | -0.3 | 0.8 | V | 5 | ||
| EN Pin input current | REN | 2.7 | 5.5 | 11 | µA | VEN=3V | 5 |
| SYNC Pin Control voltage High | VSYNCH | 2 | 5.5 | V | 5 | ||
| SYNC Pin Control voltage Low | VSYNCL | -0.3 | 0.8 | V | 5 | ||
| SYNC Pin input current | REN | 6 | 12 | 24 | µA | VSYNC=3V | 5 |
| SYNC falling edge to LX rising edge delay | tdelay | 200 | 400 | 600 | ns | 5 | |
| Power Supply Voltage | VCC | 7 | 42 | V | 5 | ||
| Output Voltage | VOUT | 1 | V | Max printed as VCC×0.7; restricted by minimum on pulse typ. 200ns | 5 |
CAD (KiCad official)
- Symbol:
BD9876AEFJ-E2 - Footprint:
Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm - 3D model: SOIC-8-EP (KiCad packages3D, STEP)
- 3D model files:
bd9876aefj-e2-etched.step/bd9876aefj-e2-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bd9876aefj-e2.step/bd9876aefj-e2.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: ROHM Semicon datasheet (26 pp, sha256
69448a0200b623f7, retrieved 2026-10-27, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-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).