TPS54331DDAR from Texas Instruments, in a SOIC-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	BOOT	output	Bootstrap capacitor node for the internal high-side MOSFET gate driver. A 0.1-µF capacitor is required between BOOT and PH. If the BOOT-PH voltage falls below the minimum requirement, the high-side MOSFET is forced off until the capacitor is refreshed. Absolute max BOOT: 38 V; BOOT-PH: 8 V.
2	VIN	power_in	Input supply voltage pin, 3.5 V to 28 V recommended operating range (absolute max 30 V). Bypass close to the pin with a low-ESR ceramic capacitor.
3	EN	input	Enable input. Pull below 1.25 V to disable the converter; float to enable. May be driven from a resistor divider off VIN to program input UVLO. Absolute max 6 V.
4	SS	input	Slow-start pin. An external capacitor from SS to GND sets the output-voltage rise time, limiting inrush current during startup.
5	VSENSE	input	Inverting input of the internal transconductance (gm) error amplifier. Connected via the output-voltage feedback divider; the amplifier regulates VSENSE to the internal 0.8-V reference.
6	COMP	output	Error-amplifier output and PWM comparator input. Connect the frequency-compensation network (typically a series R-C plus optional high-frequency pole cap) between COMP and GND.
7	GND	power_in	Device ground. On the DDA package this pin must also be connected to the exposed PowerPAD for proper thermal and electrical operation.
8	PH	output	Switch node: source of the internal high-side power MOSFET. Connect to the inductor and to the cathode of the external freewheeling (catch) diode. Handles up to ~9-A source/sink transient current.
9	PowerPAD	power_in	Exposed thermal pad on the DDA package only. Must be connected to the GND pin (pin 7) and soldered to a PCB ground plane for proper electrical and thermal performance.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOIC-8-EP
Category	PMIC
Pins	9

Ordering variants

Same part, different packaging or reel option.

TPS54331DDAR
TPS54331DDARD
TPS54331DDARDR

CAD (KiCad official)

Symbol: TPS54331DDAR
Footprint: Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm
3D model: SOIC-8-EP (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tps54331ddar.step`	125 KB	You want the bare part, or you mark your own boards.
`tps54331ddar-etched.step`	2.5 MB	You want the part with `TPS54331DDAR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 616 faces against 152 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: Texas Instruments datasheet (36 pp, sha256 94afb96d8b709e87, 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