Texas Instruments TPS3809K33DBVT

Overview

TPS3809K33DBVT from Texas Instruments is a 3-pin SOT-23 precision supply voltage supervisor IC designed for power-on reset and brownout detection in processor-based systems. It features a fixed 2.93 V threshold voltage, 200 ms reset delay time, 9 μA typical supply current, push-pull active-low RESET output, and operates across –40°C to +85°C - used in server power sequencing and industrial microcontroller startup circuits.

For engineers reviewing the TPS3809K33DBVT datasheet, TPS3809K33DBVT pinout, TPS3809K33DBVT application, or TPS3809K33DBVT equivalent, key selection criteria include threshold accuracy (±2.5% over temperature), low quiescent current for battery-backed systems, SOT-23 footprint compatibility with MAX809, and absence of external components required for basic reset functionality.

Technical Context

The TPS3809K33DBVT integrates an internal 1.137 V reference, comparator, timer, and push-pull output stage to generate a precise, glitch-free reset signal. Its threshold is set by a factory-trimmed internal resistor divider, delivering 2.93 V ±2.5% over –40°C to +85°C with 40 mV hysteresis.

During power-up, RESET asserts when VDD exceeds 1.1 V and remains active until VDD rises above 2.93 V, then holds low for 200 ms (typ) before deasserting. On undervoltage, RESET reasserts immediately when VDD falls below 2.93 V - no external capacitor or resistor needed.

Key Specifications

Pinout & Package

SOT-23 (DBV) package: 3-pin, 2.90 mm × 1.60 mm body size, 1.45 mm max height, JEDEC MO-178 compliant, tape-and-reel (250 pcs/reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV809E33DBVR, TPS3809K33DBVT trades 5.5 μA higher supply current for proven long-term reliability in industrial temperature cycling; versus MAX809TRD33+T, it eliminates pull-up dependency and reduces board space while maintaining identical threshold and pin compatibility.

Availability

TPS3809K33DBVT is available at Aetrix Electronics and suitable for factory automation, wireless speakers, and motor drives requiring stable component supply with guaranteed long-term sourcing and TI-authorized traceability.

Supply support for TPS3809K33DBVT 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 specializing in analog, embedded processing, and power management technologies, with decades of experience in high-reliability industrial and automotive ICs.

The TPS3809 family was engineered specifically for cost-sensitive, space-constrained applications needing robust, single-chip power-on reset and supply monitoring - targeting DSP, MCU, and FPGA-based systems in industrial and consumer equipment.

FAQ

What is the exact threshold voltage of the TPS3809K33DBVT?

The TPS3809K33DBVT has a nominal threshold voltage of 2.93 V, specified as 2.87 V (min) to 2.99 V (max) over –40°C to +85°C, with 40 mV hysteresis. This value is factory-trimmed and does not require external adjustment. The TPS3809K33DBVT is designed for 3.3 V supply monitoring and is distinct from other variants like TPS3809J25 (2.25 V) or TPS3809I50 (4.55 V).

Does the TPS3809K33DBVT require an external pull-up resistor on the RESET pin?

No, the TPS3809K33DBVT uses a push-pull output stage on the RESET pin, eliminating the need for an external pull-up resistor. It actively drives high or low depending on VDD status. This simplifies design compared to open-drain supervisors like the MAX809. The TPS3809K33DBVT RESET pin can directly interface with standard CMOS reset inputs without additional components.

What is the reset delay time of the TPS3809K33DBVT and how is it implemented?

The TPS3809K33DBVT provides a fixed 200 ms (typical) reset delay time after VDD rises above the 2.93 V threshold. This delay is generated by an internal timer circuit and ensures sufficient hold time for processor initialization. The TPS3809K33DBVT does not require external timing capacitors - the delay is fully integrated and temperature-compensated across its operating range.

Is the TPS3809K33DBVT pin-compatible with the MAX809 series?

Yes, the TPS3809K33DBVT is explicitly pin-for-pin compatible with the MAX809 family (e.g., MAX809TRD33+) in the SOT-23 package. Both share identical pin 1 (GND), pin 2 (RESET), and pin 3 (VDD) assignments. However, the TPS3809K33DBVT uses a push-pull output while MAX809 is open-drain - this difference affects pull-up requirements but not physical layout.

What is the recommended bypass capacitor for the TPS3809K33DBVT VDD pin?

A 0.1 µF ceramic capacitor is recommended between the VDD pin and GND for the TPS3809K33DBVT to improve threshold voltage stability and suppress high-frequency noise. Place it as close as possible to the device pins. This capacitor is essential for maintaining specification-grade accuracy, especially under dynamic load or noisy supply conditions. The TPS3809K33DBVT datasheet confirms this value in Section 6 and Figure 7-2.