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BD9D320EFJ-E2

ROHM · DC-DC Converters · HTSOP-8-EP

BD9D320EFJ-E2 from ROHM, in a HTSOP-8-EP. 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 EN input Enable input. Drive ≤0.3V to force shutdown; drive ≥2.2V to enable the device. Must not be left floating.
2 FB input Feedback input. Inverting input of the error comparator, compared against the internal 0.765V reference (VREF). Set VOUT via an external resistor divider from VOUT to FB to GND.
3 VREG power_out Internal 5.25V (Typ) LDO output used as the IC's control-circuit supply. Active when EN is above 2.2V. Bypass to GND with a 1µF ceramic capacitor.
4 SS passive Soft-start timing pin. Connect a capacitor to GND to set the output-voltage rise time during startup.
5 GND power_in Ground return for both the switching output stage and the internal control circuitry.
6 SW output Switch node. Connected to the source of the high-side MOSFET and drain of the low-side MOSFET. Connect the output inductor here (sized for the required DC current) and a 0.1µF bootstrap capacitor between SW and BOOT.
7 BOOT passive Bootstrap capacitor node. Connect a 0.1µF capacitor between BOOT and SW; this capacitor generates the gate-drive voltage for the high-side MOSFET (VBOOT-VSW = 4.5-5.5V recommended).
8 VIN power_in Power-supply input for the switching regulator. Recommended operating range 4.5V to 18V (20V absolute max). Bypass to GND with 20µF (10µF×2) plus 0.1µF ceramic capacitors close to the pin.
9 FIN power_in Exposed backside heat-dissipation pad. Connect to the internal PCB ground plane with multiple thermal vias for good heat dissipation. Electrically tied to GND.

Key specifications

Parameter Value
Manufacturer ROHM
Package HTSOP-8-EP
Category PMIC
Pins 9

Ordering variants

  • BD9D320EFJ-E2

CAD (KiCad official)

  • Symbol: BD9D320EFJ-E2
  • Footprint: Package_SO:HTSOP-8-1EP_3.9x4.9mm_P1.27mm_EP2.4x3.2mm
  • 3D model: HTSOP-8-EP (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: ROHM datasheet (None pp, sha256 be034a3b51edf91c, retrieved 2026-08-17, tier: lcsc)
  • 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

Symbol & Footprint

Schematic Symbol

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PCB Footprint

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