Texas Instruments TPS3847085DBVR

Overview

TPS3847085DBVR from Texas Instruments is an ultralow-power voltage supervisor IC that monitors a 4.5 V–18 V supply rail and asserts an active-low reset signal when V_CC drops below its factory-trimmed 8.5 V threshold (±2.5% accuracy). It features a push-pull output, 380 nA typical supply current at 25°C, 20 ms max reset delay, and operates across –40°C to +85°C. It is used in battery-powered systems where long-term supply integrity and minimal quiescent drain are critical.

For engineers reviewing the TPS3847085DBVR datasheet, TPS3847085DBVR pinout, TPS3847085DBVR application, or TPS3847085DBVR equivalent, key selection considerations include its fixed 8.5 V detection threshold, SOT-23-5 package compatibility, MR pin support for processor-initiated resets, and guaranteed operation up to +105°C junction temperature despite rated spec range ending at +85°C.

Technical Context

The TPS3847085DBVR implements a precision bandgap-based voltage reference with internal resistor trimming to achieve ±2.5% negative-going threshold accuracy without external components. Its sampling architecture enables ultralow 380 nA average supply current while maintaining reliable detection of supply dips as short as 55 µs (V_CC falling) or 50 µs (MR falling).

It operates in two functional modes: (1) automatic supervision-RESET goes low when V_CC < 8.5 V and returns high after ≥20 ms once V_CC exceeds 8.5 V + hysteresis (≈0.935 V); and (2) manual reset mode-asserting MR low forces RESET low regardless of V_CC, with recovery requiring both MR high and V_CC > 8.5 V + hysteresis.

Key Specifications

Pinout & Package

TPS3847085DBVR is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, optimized for space-constrained PCB layouts and compatible with standard pick-and-place equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3847085DBVR, the DBVT offers identical performance in smaller packaging for development use, while TLV803EB85DBVR serves fundamentally different low-voltage applications and cannot substitute without circuit redesign.

Availability

TPS3847085DBVR is available at Aetrix Electronics and suitable for portable medical sensors, lithium-ion battery protection circuits, industrial PLC I/O modules, and smart energy meters requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for TPS3847085DBVR 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 high-reliability ICs.

The TPS3847 family was designed specifically for ultralow-power, high-voltage supervision in battery-critical and industrial applications-emphasizing sub-µA quiescent current, factory-trimmed thresholds, and robust operation across extended temperature ranges.

FAQ

What is the exact reset threshold voltage of the TPS3847085DBVR?

The TPS3847085DBVR has a factory-trimmed negative-going reset threshold of 8.5 V with ±2.5% accuracy over temperature. This value is specified as V_IT− = 8.5 V (min 8.2875 V, max 8.7125 V at 25°C). The positive-going threshold (V_IT+) is approximately 9.435 V due to built-in hysteresis of 0.935 V. These values are confirmed in Section 6.5 of the SBVS231A datasheet.

Does the TPS3847085DBVR require an external capacitor on the VCC pin?

Yes, the TPS3847085DBVR requires a 0.1 µF ceramic bypass capacitor placed as close as possible to the V_CC pin and GND. This is necessary because the device draws ~12 µA for ~500 µs every ~200 ms during internal reference refresh. Without the capacitor, high-impedance supply paths may cause voltage droop sufficient to trigger false resets. TI explicitly recommends this in Sections 8.2.1.1 and 10.1 of the datasheet.

Can the TPS3847085DBVR operate reliably at 105°C ambient temperature?

The TPS3847085DBVR is specified for operation from –40°C to +85°C, but TI confirms functional operation up to +105°C junction temperature, as evidenced by Typical Characteristics plots (Figures C002, C004, C005, C007, C008, C010, C011) covering –40°C to +105°C. While long-term reliability at 105°C should be verified per application, the device's electrical behavior remains valid across that extended range per SBVS231A revision March 2015.

What is the purpose of the NC pin on the TPS3847085DBVR?

Pin 3 of the TPS3847085DBVR is labeled NC (No Connection) and has no internal bond wire or circuit connection. It must remain unconnected on the PCB layout. TI's Pin Configuration and Functions table (Section 5) explicitly states "No internal connection." Leaving it floating or routing traces to it may introduce parasitic capacitance or mechanical stress, potentially affecting thermal performance or ESD robustness.

How does the MR pin function on the TPS3847085DBVR?

The MR (Manual Reset) pin on the TPS3847085DBVR allows external logic to force RESET low regardless of V_CC. When MR is pulled below 0.4 V (V_IL), RESET transitions low after 50 µs propagation delay. When MR rises above 1.2 V (V_IH) and V_CC exceeds the positive-going threshold (~9.435 V), RESET returns high after the 20 ms delay. If unused, MR must be tied directly to V_CC; floating is prohibited per Section 8.3 "Do's and Don'ts".