Watches a supply rail and a microcontroller at once: it holds RESET asserted until the rail rises above a fixed threshold and a 200 ms delay elapses, and a watchdog input (WDI) must be toggled by the MCU within a time-out or the supervisor issues a reset. A manual-reset input (MR) forces a reset on command. That covers both brownout and firmware-hang recovery in one small SOT-23-5. A common companion to any microcontroller that must recover itself.

Pinout

Pin	Name	Type	Function
1	RESET	output	Active-low reset output, push-pull. Asserts low while VDD is below the negative-going threshold VIT- (e.g. 2.93 V nominal for TPS3823-33) and remains low for the delay time td (200 ms nom) after VDD rises above the threshold. Also asserts on MR pulled low or on watchdog time-out.
2	GND	power_in	Ground / device return.
3	MR	input	Manual reset input, active low. Pulling MR low forces RESET low; RESET remains asserted while MR is low and for the delay time td after MR returns high. Has an internal ~90 kOhm pullup to VDD, so it can be left unconnected or tied to VDD when unused.
4	WDI	input	Watchdog timer input. Must be toggled (rising or falling edge) within the watchdog time-out t_tout (1.6 s nominal for TPS3823) or a reset is triggered. If WDI is left floating the device internally generates pulses to prevent a watchdog reset; WDI must be driven fully high or fully low for the watchdog to detect an error.
5	VDD	power_in	Supply voltage input. Powers the device and is the monitored rail. Recommended operating range 1.1 V to 5.5 V (absolute max 6 V). Place a 0.1 uF ceramic bypass capacitor close to this pin for best threshold stability.

Key specifications

Parameter	Value
Type	Voltage supervisor + watchdog
Threshold	Fixed (order code)
Reset delay	200 ms (typ)
Watchdog	WDI time-out
Manual reset	MR input
Output	Active-low RESET
Supply	1.1-5.5 V
Package	SOT-23-5

Ordering variants

Same part, different packaging or reel option.

TPS3823-33DBVR (3.3 V)
TPS3823-50DBVR (5.0 V)
TPS3823A-33DBVR (active-high reset)

CAD (KiCad official)

Symbol: Power_Supervisor:TPS3823-xxDBV (KiCad official)
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Texas Instruments datasheet (34 pp, sha256 3351e38aaf2f0a71, 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