Texas Instruments TPS3808EG33DBVR

Overview

TPS3808EG33DBVR from Texas Instruments is a low-quiescent-current, fixed-threshold supervisory circuit designed to monitor 3.3V power rails and assert an open-drain RESET signal upon undervoltage detection. It features 1% typical threshold accuracy (3.07V), 0.6μA typical supply current, user-programmable reset delay from 1.25ms to 10s via external capacitor on CT pin, and operates across –40°C to +125°C. Used in rack server motherboards and surgical equipment for reliable power-on sequencing.

For engineers reviewing the TPS3808EG33DBVR datasheet, TPS3808EG33DBVR pinout, TPS3808EG33DBVR application, or TPS3808EG33DBVR equivalent, key selection considerations include its 3.07V undervoltage threshold, SOT-23-6 package compatibility with space-constrained PCB layouts, manual reset (MR) input for system-initiated resets, and precision timing control via CT pin configuration - all critical for battery-powered and industrial embedded designs requiring stable reset behavior under voltage transients.

Technical Context

The TPS3808EG33DBVR implements a precision comparator with 0.5% internal reference accuracy to detect SENSE voltage drops below 3.07V, triggering an open-drain RESET output. Its reset assertion is governed by dual inputs: SENSE voltage falling below VIT-(UV) or MR pin driven low (≤0.3×VDD), with hysteresis (1–2.5%) ensuring noise immunity.

Reset deassertion requires both SENSE > VIT + VHYS and MR > 0.7×VDD, followed by a programmable delay determined by charging a capacitor on CT via a 220nA internal current source. The device supports three delay modes: 20ms (CT open), 300ms (CT tied to VDD via 40–200kΩ), or 1.25ms–10s (CT–GND capacitor ≥130pF).

Key Specifications

Pinout & Package

TPS3808EG33DBVR is housed in a compact 6-pin SOT-23 (DBV) package measuring 2.90mm × 1.60mm, 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 supervisory circuit applications.

Compared with TPS3808G33DBVR, the TPS3808EG33DBVR delivers lower quiescent current and extended temperature support; versus MAX6326LT33D2T, it adds MR functionality and wide delay programmability - making TPS3808EG33DBVR optimal for high-reliability, battery-sensitive, and timing-critical applications.

Availability

TPS3808EG33DBVR is available at Aetrix Electronics and suitable for rack server motherboard design, electricity meter production, and DC-input BLDC motor drive development requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for TPS3808EG33DBVR 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 company specializing in analog and embedded processing technologies, with leadership in power management, signal chain, and high-reliability ICs.

The TPS3808E product line was engineered for ultra-low-power, high-accuracy power-supply monitoring in mission-critical industrial, medical, and computing systems - emphasizing precision threshold stability, flexible reset timing, and robust operation across extreme temperatures.

FAQ

What is the exact undervoltage threshold voltage of the TPS3808EG33DBVR?

The TPS3808EG33DBVR has a nominal undervoltage threshold of 3.07V, with ±0.5% accuracy over temperature (–40°C to +125°C). This value corresponds to the 3.3V nominal supply rail and is factory-trimmed; it is specified as VIT-(UV) in the electrical characteristics table and applies to negative-going transitions on the SENSE pin. The TPS3808EG33DBVR does not require external resistors to achieve this threshold.

How is the reset delay time configured on the TPS3808EG33DBVR?

The TPS3808EG33DBVR supports three reset delay configurations via the CT pin: open circuit yields 20ms, connection to VDD through a 40–200kΩ resistor gives 300ms, and connection to GND via a capacitor (≥130pF) enables user-programmable delays from 1.25ms to 10s. The delay is generated by an internal 220nA current source charging the external capacitor; ceramic capacitors are required for accuracy. The TPS3808EG33DBVR datasheet provides Equation 1 for calculating CT value based on desired delay.

Does the TPS3808EG33DBVR have a manual reset (MR) input, and how is it used?

Yes, the TPS3808EG33DBVR includes a dedicated MR pin (Pin 3) that asserts RESET when driven to ≤0.3×VDD. It features an internal 90kΩ pull-up resistor to VDD, allowing direct connection to GPIO outputs without external biasing. When MR is low, RESET remains asserted regardless of SENSE voltage; deassertion occurs only after MR returns high, SENSE exceeds 3.07V + hysteresis, and the programmed delay expires. This capability makes the TPS3808EG33DBVR suitable for system-initiated resets in applications like surgical equipment emergency shutdown.

What package type and dimensions does the TPS3808EG33DBVR use?

The TPS3808EG33DBVR is packaged in a 6-pin SOT-23 (DBV) case with nominal body dimensions of 2.90mm × 1.60mm and a maximum height of 1.30mm. It is RoHS-compliant, lead-free (NiPdAu finish), and rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH). The pinout follows standard SOT-23 orientation: RESET (1), GND (2), MR (3), CT (4), SENSE (5), VDD (6), as verified in the TI datasheet Figure 5-1 and Package Option Addendum.

Can the TPS3808EG33DBVR monitor a voltage rail different from its own supply voltage?

Yes, the TPS3808EG33DBVR supports independent SENSE and VDD rails: the SENSE pin monitors the 3.3V target rail (with 3.07V threshold), while VDD can be supplied from a separate 1.7–6V source (e.g., 5V or 12V converted down). This separation allows the TPS3808EG33DBVR to supervise critical logic rails even when its own supply is derived from a higher or more robust domain - a key advantage in multi-rail systems like rack server motherboards where 3.3V integrity must be validated independently of 5V or 12V supplies.