Texas Instruments TPS3839K33DQNR

Overview

TPS3839K33 from Texas Instruments is an ultralow-power voltage supervisor IC designed for supply monitoring in battery-critical systems. It features a factory-trimmed 2.93 V reset threshold, 150 nA typical supply current, push-pull RESET output, and valid operation down to 0.6 V VDD - enabling reliable power-on reset in 3.3 V microprocessor applications.

For engineers reviewing the TPS3839K33 datasheet, TPS3839K33 pinout, TPS3839K33 application, or TPS3839K33 equivalent, key selection considerations include its 200 ms reset delay, ±1% threshold accuracy at 25°C, SOT-23-3 package compatibility, and transient rejection capability for fast VDD dips.

Technical Context

The TPS3839K33 implements a precision comparator-based supervision architecture with built-in hysteresis (29 mV typical) to prevent oscillation during supply recovery. Its internal sampling circuit operates intermittently to maintain ultralow quiescent current, drawing ~15 µA only during brief 200 µs voltage-sampling windows.

Unlike the TPS3831 variant, the TPS3839K33 omits the manual reset (MR) input and uses a 3-pin SOT-23 (DBZ) package. It asserts an active-low RESET signal when VDD falls below 2.857 V (min) and holds it for 120–350 ms after VDD rises above the threshold plus hysteresis.

Key Specifications

Pinout & Package

TPS3839K33 is housed in a 3-pin SOT-23 (DBZ) package measuring 2.92 mm × 2.37 mm, optimized for space-constrained portable designs. The package has no thermal pad and uses standard surface-mount reflow profiles (MSL Level-1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3831K33DQNR, the TPS3839K33 saves one pin and removes MR complexity but sacrifices reset flexibility; versus MAX6373KA33+T, it delivers 10× lower quiescent current and documented transient rejection - critical for noise-prone industrial environments.

Availability

TPS3839K33 is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor nodes, wearable fitness trackers, and smart metering modules requiring stable component supply across long production lifecycles.

Supply support for TPS3839K33 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The TPS383x family was developed specifically for ultralow-power supply monitoring in battery-operated equipment, targeting applications where nanoscale current budgets and precise voltage thresholds determine product viability.

FAQ

What is the minimum supply voltage required for TPS3839K33 to assert a valid RESET signal?

The TPS3839K33 guarantees a valid RESET output down to 0.6 V VDD, meaning it will correctly assert the active-low RESET signal even as the supply collapses toward zero. Below 0.6 V, the output state is undefined per the datasheet - so system designers must ensure critical functions complete before VDD reaches this point. This behavior is confirmed in Section 7.5 Electrical Characteristics under V(POR) parameter.

Does TPS3839K33 support manual reset functionality like some other TI supervisors?

No, the TPS3839K33 does not include a manual reset (MR) input. That feature is exclusive to the TPS3831 series (e.g., TPS3831K33DQNR), which uses a 4-pin X2SON package. The TPS3839K33 is strictly a VDD-only supervisor in a 3-pin SOT-23 configuration - simplifying layout but removing external reset initiation capability.

How does the 200 ms reset delay of TPS3839K33 impact microcontroller boot timing?

The 200 ms typical reset delay ensures the TPS3839K33 holds RESET low long enough for most 3.3 V microcontrollers to complete internal oscillator stabilization, PLL lock, and flash initialization. For example, ARM Cortex-M0+ MCUs typically require 10–100 ms for clock startup - making the 120–350 ms guaranteed delay range robust against process and temperature variation.

Can TPS3839K33 be used with a 1.8 V supply rail?

Yes, the TPS3839K33 operates across 0.9 V to 6.5 V, so it fully supports 1.8 V systems. However, its 2.93 V reset threshold means it cannot supervise a 1.8 V rail directly - it would remain deasserted. To monitor 1.8 V, select a variant like TPS3839G18 (1.67 V threshold) or use an external resistor divider (not recommended due to added current and accuracy loss).

What is the purpose of the 0.1 µF capacitor recommended on the VDD pin of TPS3839K33?

The 0.1 µF bypass capacitor mitigates voltage droop caused by the TPS3839K33's periodic 15 µA, 200 µs sampling current. Without it, high-impedance supplies (e.g., RC-filtered LDO outputs or long PCB traces) may sag enough during sampling to trigger false resets. Placing the capacitor within 2 mm of the VDD pin ensures low-impedance local energy storage during each sampling event.