Texas Instruments TPS3839A09DBZR

Overview

TPS3839A09DBZR from Texas Instruments is an ultralow-power voltage supervisor IC designed for single-supply monitoring in battery-critical systems. It features a factory-trimmed 0.9 V reset threshold, 150 nA typical supply current at 25°C, push-pull RESET output, and valid operation down to 0.6 V VDD - enabling reliable power-on reset in single-cell alkaline applications.

For engineers reviewing the TPS3839A09DBZR datasheet, TPS3839A09DBZR pinout, TPS3839A09DBZR application, or TPS3839A09DBZR equivalent, key selection criteria include its sub-1-V threshold accuracy, temperature-stable hysteresis (54 mV), 200 ms reset delay, SOT23-3 package footprint, and immunity to fast VDD transients per Figure 13.

Technical Context

The TPS3839A09DBZR implements a precision comparator-based supervision architecture with internal hysteresis (54 mV) and a fixed 200 ms reset delay after VDD recovery. Its sampling circuitry draws ~15 µA for ~200 µs during voltage monitoring, maintaining average IDD at 150 nA - critical for multi-year battery life in wearables and glucose monitors.

Unlike the TPS3831 family, this variant omits the manual reset (MR) input and uses a 3-pin SOT23-3 package (VDD, GND, RESET), simplifying layout while retaining full threshold accuracy (±1% at 25°C) and operating range (–40°C to +85°C).

Key Specifications

Pinout & Package

SOT23-3 package (2.92 mm × 2.37 mm), surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3831A09DQNR, the TPS3839A09DBZR saves board space and removes MR complexity; versus MAX6370XR29+T, it delivers 8× lower current and true sub-1-V supervision - making it irreplaceable in ultra-low-power, single-cell designs.

Availability

TPS3839A09DBZR is available at Aetrix Electronics and suitable for portable medical devices, battery-powered metering, and industrial IoT edge nodes requiring stable component supply over extended production lifecycles.

Supply support for TPS3839A09DBZR 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 for industrial, automotive, and personal electronics markets.

The TPS383x product line was engineered specifically for ultralow-power voltage supervision in battery-constrained applications - prioritizing nanoamp current, sub-1-V thresholds, and transient-immune reset timing.

FAQ

What is the minimum supply voltage at which TPS3839A09DBZR asserts a valid RESET signal?

The TPS3839A09DBZR asserts a valid RESET signal down to 0.6 V VDD, as specified by the V(POR) parameter in Section 7.5. Below this voltage, the RESET output state is undefined. This 0.6 V POR level ensures reliable reset assertion even during severe brownout conditions in single-cell alkaline systems, and is confirmed in the Electrical Characteristics table under "Minimum VDD voltage for valid output".

Does TPS3839A09DBZR support manual reset functionality?

No, the TPS3839A09DBZR does not include a manual reset (MR) input. Pin configuration data confirms it is a 3-pin SOT23 device with only VDD, GND, and RESET terminals. Manual reset is exclusive to the TPS3831 series (e.g., TPS3831A09DQNR), which uses a 4-pin X2SON package and dedicates Pin 2 to MR. This distinction is explicitly stated in the Pin Functions table and Device Options section.

What is the guaranteed reset delay time for TPS3839A09DBZR across temperature?

The reset delay time (td) for TPS3839A09DBZR is guaranteed between 120 ms and 350 ms over the full operating temperature range (–40°C to +85°C), with 200 ms typical at 25°C. This is documented in Section 7.6 (Timing Requirements) and verified in Figure G002 ("Reset Delay vs Temperature"), which shows measured values staying within spec across all tested temperatures.

Can TPS3839A09DBZR drive a microcontroller's bidirectional reset pin directly?

TPS3839A09DBZR can drive a bidirectional reset pin, but requires a series current-limiting resistor (e.g., 1–10 kΩ) between RESET and the MCU pin. This protects against contention if both devices attempt to drive the line simultaneously - a requirement explicitly called out in Section 9.2.2.2 ("Bidirectional Reset Pins") and illustrated in Figure 16 of the datasheet.

How does TPS3839A09DBZR achieve 150 nA supply current while maintaining accuracy?

The TPS3839A09DBZR achieves 150 nA typical supply current via periodic sampling: it draws ~15 µA for ~200 µs every ~100 ms to measure VDD, resulting in a 0.2% duty cycle and ultra-low average current. This architecture is detailed in Section 9.2.2.1 ("Input Capacitor") and validated in Figure G001 ("Supply Current vs Temperature"), where measured current remains stable across –40°C to +85°C at all supply voltages.