Texas Instruments TPS3808G18DBVT

Overview

TPS3808G18DBVT from Texas Instruments is a low-quiescent-current, programmable-delay supervisory circuit designed to monitor 1.8-V system rails and assert an open-drain RESET signal upon undervoltage or manual reset assertion. It delivers 0.5% threshold accuracy (V_IT = 1.67 V), 2.4 μA typical supply current, and user-adjustable reset delay from 1.25 ms to 10 s via external capacitor on CT pin - enabling reliable power-on reset in battery-powered microcontroller systems.

For engineers reviewing the TPS3808G18DBVT datasheet, TPS3808G18DBVT pinout, TPS3808G18DBVT application, or TPS3808G18DBVT equivalent, key selection criteria include its SOT-23-6 package compatibility, −40°C to 125°C operating range, fixed 1.67-V threshold for 1.8-V rails, open-drain RESET output with 0.4-V low-level voltage at 1 mA, and MR input with 90-kΩ internal pullup - all critical for embedded power sequencing and brownout protection.

Technical Context

The TPS3808G18DBVT implements a precision voltage comparator with built-in hysteresis (1% of V_IT) and a 220-nA on-chip current source that charges the external CT capacitor to set reset delay. Its SENSE input monitors the 1.8-V rail directly, while the MR pin supports logic-level reset initiation independent of supply voltage.

It operates across 1.7–6.5 V supply range and uses a factory-trimmed reference to maintain ±0.5% V_IT accuracy over temperature (−40°C to 125°C). The open-drain RESET output requires an external pullup (10 kΩ–1 MΩ) and supports voltages up to 6.5 V, enabling interface with higher-voltage logic domains.

Key Specifications

Pinout & Package

SOT-23-6 (DBV) package: 2.90 mm × 1.60 mm body, surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar supervisory circuit applications.

Compared with TPS3808G18DBVT, TPS3808G18DBVR offers identical performance in volume packaging, while MAX6326LT18D3+T trades programmability and MR support for reduced pin count and marginally higher quiescent current - making it suitable only for static timing requirements.

Availability

TPS3808G18DBVT is available at Aetrix Electronics and suitable for microcontroller power sequencing, battery-powered sensor nodes, FPGA configuration hold, and industrial PLC I/O modules requiring stable component supply with guaranteed long-term sourcing.

Supply support for TPS3808G18DBVT 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 delivering analog and embedded processing solutions, with leadership in power management, signal chain, and microcontrollers.

The TPS3808 family is engineered for precision voltage supervision in space-constrained, low-power systems - targeting applications where accurate reset timing, minimal current draw, and wide temperature operation are essential.

FAQ

What is the exact threshold voltage of the TPS3808G18DBVT and how is it trimmed?

The TPS3808G18DBVT has a nominal threshold voltage (V_IT) of 1.67 V, factory-trimmed to ±0.5% accuracy over −40°C to 125°C. This value corresponds to the 1.8-V nominal supply rail and is achieved using TI's precision voltage reference architecture with on-die trimming - no external resistors or calibration are needed for standard 1.8-V monitoring. The TPS3808G18DBVT maintains this accuracy without drift across its full operating temperature and supply range.

Can the TPS3808G18DBVT be used to monitor voltages other than 1.8 V?

No - the TPS3808G18DBVT is a fixed-threshold variant optimized specifically for 1.8-V rails (V_IT = 1.67 V). To monitor other voltages, select alternate members of the TPS3808 family such as TPS3808G33 (3.07 V) or TPS3808G01 (adjustable down to 0.405 V). Using the TPS3808G18DBVT for non-1.8-V rails would result in incorrect reset assertion points and is not supported by TI's specifications.

How does the CT pin configure reset delay on the TPS3808G18DBVT?

The CT pin on the TPS3808G18DBVT sets reset delay via three configurations: open circuit yields 20 ms, connection to V_DD through 40–200 kΩ gives 300 ms, and connection to ground via ≥100-pF capacitor enables user-programmable delay from 1.25 ms to 10 s. The internal 220-nA current source charges the capacitor to 1.23 V; RESET deasserts when that voltage is reached. Ceramic capacitors are recommended to minimize leakage-induced timing error in the TPS3808G18DBVT.

Is the MR pin on the TPS3808G18DBVT mandatory to use?

No - the MR pin on the TPS3808G18DBVT is optional. It features an internal 90-kΩ pullup to V_DD, so leaving it unconnected disables manual reset functionality entirely. When used, MR asserts RESET when driven ≤0.3×V_DD; it does not require external biasing. This design simplifies schematics in systems where only power-supply monitoring is required, preserving the TPS3808G18DBVT's low-component-count advantage.

What is the maximum allowable voltage on the RESET pin of the TPS3808G18DBVT?

The RESET pin of the TPS3808G18DBVT supports voltages up to 6.5 V, independent of V_DD. As an open-drain output, it can be pulled up to any voltage within the absolute maximum rating (−0.3 V to 7 V), enabling interface with higher-voltage logic families (e.g., 5-V microcontrollers) even when V_DD is 1.8 V. A minimum 10-kΩ pullup resistor is required to limit current and ensure proper high-impedance release in the TPS3808G18DBVT.