Texas Instruments TPS3820-50DBVR

Overview

TPS3820-50DBVR from Texas Instruments is a 5-pin SOT-23 voltage supervisor IC with integrated watchdog timer, fixed 4.55 V threshold (V_IT−), 25 ms reset delay (t_d), and active-low push-pull RESET output - designed for reliable power-on reset and fault recovery in microcontroller-based systems operating from 1.1 V to 5.5 V.

For engineers reviewing the TPS3820-50DBVR datasheet, TPS3820-50DBVR pinout, TPS3820-50DBVR application, or TPS3820-50DBVR equivalent, key selection criteria include its 25 ms reset timeout (shorter than standard 200 ms variants), 4.55 V supervision level, manual reset input (MR), watchdog timer input (WDI), and −40°C to 85°C industrial temperature range.

Technical Context

The TPS3820-50DBVR implements a fixed-threshold voltage supervision architecture with internal hysteresis (50 mV) and an independent watchdog timer that triggers on missing WDI transitions. Its reset assertion begins when VDD rises above 1.1 V, and it holds RESET low until VDD exceeds V_IT− + V_HYS, then enforces a precise 25 ms delay before release.

Unlike TPS3823/3824 variants, the TPS3820-50DBVR uses only active-low RESET output (no active-high RESET pin), includes MR for external reset initiation, and features a dedicated WDI input with internal pulse generation when floating - enabling robust system-level fault detection without external timing components.

Key Specifications

Pinout & Package

TPS3820-50DBVR is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, optimized for high-density PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with TPS3823-50DBVR, the TPS3820-50DBVR reduces reset duration by 75%, accelerating system readiness; versus MAX6326–MAX6329, it integrates watchdog capability and eliminates external component dependencies for fault detection.

Availability

TPS3820-50DBVR is available at Aetrix Electronics and suitable for industrial PLC modules, battery-powered wireless sensors, notebook platform controllers, and microcontroller-based edge devices requiring stable component supply with guaranteed long-term availability.

Supply support for TPS3820-50DBVR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The TPS382x product line was engineered specifically for reliable power-supply monitoring and system-level fault recovery in processor-based applications - emphasizing precision threshold accuracy, low power consumption, and integrated watchdog functionality in minimal footprint packages.

FAQ

What is the exact reset threshold voltage for TPS3820-50DBVR?

The TPS3820-50DBVR has a negative-going input threshold voltage (V_IT−) of 4.46 V (min), 4.55 V (typ), and 4.64 V (max) across −40°C to 85°C. This 5 V nominal supervision point is factory-trimmed and does not require external calibration. The device also includes 50 mV hysteresis to prevent chatter during slow-rising or noisy supply conditions. All values are specified in the Electrical Characteristics table of the official TI datasheet SLVS165O.

Does TPS3820-50DBVR support active-high reset output?

No, TPS3820-50DBVR provides only an active-low push-pull RESET output (Pin 1). It does not include the separate active-high RESET pin found on TPS3824/TPS3825 variants. If your system requires active-high reset signaling, you must use an external inverter or select TPS3824-50DBVR instead. The TPS3820-50DBVR's RESET pin drives low during fault conditions and returns high after the 25 ms delay expires - no additional logic is needed for standard microcontroller reset inputs.

How does the watchdog timer in TPS3820-50DBVR operate?

The watchdog timer in TPS3820-50DBVR monitors the WDI (Pin 4) input and triggers a reset if no falling edge occurs within 112–300 ms (typ. 200 ms). Each valid falling edge clears the timer. If WDI is left unconnected, the device internally generates pulses to prevent false timeouts. To disable watchdog functionality, tie WDI to VDD or GND - but note that tying to GND will continuously assert RESET. The TPS3820-50DBVR does not latch WDI faults; it responds dynamically to edge timing.

Can TPS3820-50DBVR be used with a 3.3 V supply rail?

No, TPS3820-50DBVR is specifically configured for 5 V rail supervision with a 4.55 V threshold. Using it on a 3.3 V system would cause continuous RESET assertion because VDD never exceeds V_IT−. For 3.3 V applications, select TPS3820-33DBVR (2.93 V threshold) or TPS3823-33DBVR. The "-50" suffix explicitly denotes the 5 V variant, and threshold voltage is laser-trimmed per part number - cross-voltage usage is not supported and violates absolute maximum ratings.

What is the function of the MR pin on TPS3820-50DBVR?

The MR (Manual Reset) pin (Pin 3) on TPS3820-50DBVR is an active-low input that forces immediate RESET assertion regardless of VDD level or watchdog status. Pulling MR low holds RESET low for the full 25 ms delay period, even if VDD remains above threshold. When unused, MR may be left open (internally pulled up to VDD via 90 kΩ) or tied to VDD. It enables hardware-initiated resets from pushbuttons, FPGA outputs, or fault-detection circuits - providing fail-safe recovery independent of software control.