TPS3705-33DR from Texas Instruments, in a SOIC-8. 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	MR	input	Manual reset input (active low). Driving this pin low asserts RESET for the fixed 200 ms reset timeout period. Internally pulled up; can be left open if unused.
2	VDD	power_in	Supply voltage input. Recommended operating range 2 V to 6 V (absolute max 7 V). Nominal supply current 50 μA max. Monitored against internal fixed threshold V_IT+ = 2.93 V (3.3 V option).
3	GND	power_in	Device ground reference. All voltage measurements are with respect to GND.
4	PFI	input	Power-fail comparator input. Compared against an internal reference (typ. 1.25 V); a resistor divider from the monitored rail sets the trip point. Drives PFO low when V_PFI falls below the reference.
5	PFO	output	Power-fail comparator output (active low). Open-drain/push-pull digital output that asserts low when V_PFI is below the internal reference, providing early warning of an impending supply loss or low-battery condition.
6	WDI	input	Watchdog timer input. Must be toggled by the host within the watchdog timeout window; missing an edge causes WDO to assert. Can be left floating to disable watchdog function.
7	RESET	output	Active-low reset output. Asserted low while V_DD is below V_IT+ or during power-up (V_DD < 1.1 V), and held low for the fixed 200 ms timeout after V_DD returns above V_IT+. Also asserted by MR low.
8	WDO	output	Watchdog timer output (active low). Asserted low when WDI has not toggled within the watchdog timeout period, signaling a host lockup.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

TPS3705-33DR
TPS3705-33DGN
TPS3705-33DGNR

CAD (KiCad official)

Symbol: TPS3705-33DR
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tps3705-33dr.step`	122 KB	You want the bare part, or you mark your own boards.
`tps3705-33dr-etched.step`	2.7 MB	You want the part with `TPS3705-33DR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 640 faces against 147 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 (29 pp, sha256 4a3d7db6b372dd6a, 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