Texas Instruments LP3470A275DBVR

Overview

LP3470A275DBVR from Texas Instruments is an ultra-low-power voltage supervisor IC designed for precise power-on reset and brownout detection in microcontroller systems. It features a factory-programmed 2.75 V reset threshold (VIT−), ±1% accuracy over temperature, 0.3 µA typical quiescent current, open-drain RESET output, and programmable reset delay via external capacitor on SRT pin - used in battery-powered instrumentation and industrial controllers.

For engineers reviewing the LP3470A275DBVR datasheet, LP3470A275DBVR pinout, LP3470A275DBVR application, or LP3470A275DBVR equivalent, key selection criteria include reset threshold tolerance at −40°C to 125°C, minimum VCC operation down to 0.95 V, SRT capacitor-based timing flexibility, and compatibility with 5-pin SOT-23 PCB footprints.

Technical Context

The LP3470A275DBVR implements a precision bandgap reference and comparator architecture to monitor VCC against a fixed 2.75 V threshold (VIT−) with 100 mV hysteresis (VHYS). Its internal RSRT resistor (~500 kΩ) forms an RC time constant with the external SRT capacitor to generate reset delay (tD), ranging from 50 µs (SRT floating) to 619 ms (1 µF) or 6.2 s (10 µF).

It operates across −40°C to 125°C with guaranteed RESET assertion down to VCC = 0.95 V and immunity to short VCC transients up to 10 µs duration at 5% overdrive. The open-drain RESET output requires an external pull-up and sinks ≥2 mA while maintaining VOL ≤ 200 mV.

Key Specifications

Pinout & Package

LP3470A275DBVR is housed in a 5-pin SOT-23 (DBV) package measuring 1.60 mm × 2.90 mm, optimized for space-constrained PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G27DBVR and MAX6326LT27D3+T, the LP3470A275DBVR offers superior nano-power operation (0.3 µA vs ≥1.5 µA), full timing programmability, and wider VCC range (0.95–10 V), making it optimal for long-life, field-deployed equipment where timing adaptability and low-voltage robustness are critical.

Availability

LP3470A275DBVR is available at Aetrix Electronics and suitable for industrial sensor nodes, smart building controllers, portable medical monitors, and factory automation I/O modules requiring stable component supply across extended product lifecycles.

Supply support for LP3470A275DBVR 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 delivering analog and embedded processing solutions, with over 50 years of innovation in power management, signal chain, and real-time control ICs.

The LP3470A275DBVR belongs to TI's ultra-low-power voltage supervisor family, engineered specifically for high-reliability power monitoring in battery-critical and thermally demanding industrial applications - emphasizing accuracy, longevity, and design flexibility.

FAQ

What is the exact reset threshold voltage of LP3470A275DBVR?

The LP3470A275DBVR has a factory-programmed negative-going input threshold (VIT−) of 2.75 V with ±1% accuracy over −40°C to 125°C. This value is laser-trimmed during production and confirmed in TI's Electrical Characteristics table; it is distinct from the 2.85 V positive-going threshold (VIT+) due to 100 mV hysteresis. The LP3470A275DBVR datasheet specifies this as the primary reset trigger point for brownout detection.

How do I calculate the reset delay time for LP3470A275DBVR using an external capacitor?

For LP3470A275DBVR, the reset delay tD (in seconds) is calculated as tD = 618937 × CSRT + 50 µs, where CSRT is the capacitor value in farads connected between SRT (Pin 1) and GND. For example, a 100 nF capacitor yields tD ≈ 61.9 ms. The LP3470A275DBVR's internal SRT resistor (~500 kΩ) and fixed offset enable this linear approximation across the full 1 nF–10 µF range.

Can LP3470A275DBVR operate with a 1.8 V supply rail?

No - LP3470A275DBVR requires VCC ≥ 0.95 V to assert RESET, but its 2.75 V reset threshold means it cannot supervise a 1.8 V rail. It is intended for systems with nominal supplies ≥ 3.0 V (e.g., 3.3 V, 5 V). For 1.8 V supervision, TI recommends LP3470A180DBVR (1.8 V variant) or alternative families like TPS3808G18. The LP3470A275DBVR specification explicitly defines VIT− = 2.75 V and does not support lower-threshold operation.

Is LP3470A275DBVR pin-compatible with the original LP3470?

Yes - LP3470A275DBVR is explicitly documented as pin-to-pin compatible with the legacy LP3470 in TI's datasheet Feature section. Both use identical 5-pin SOT-23 (DBV) packaging, matching pinout (SRT/GND/VCC1/VCC/RESET), and share identical absolute maximum ratings and recommended operating conditions. No PCB layout changes are required when upgrading from LP3470 to LP3470A275DBVR.

What is the maximum capacitor value supported on the SRT pin of LP3470A275DBVR?

The recommended maximum capacitor on the SRT pin of LP3470A275DBVR is 10 µF, as specified in Section 8.3.1 of the datasheet. Larger values risk incomplete discharge during brief brownout events, causing inaccurate delay timing. With 10 µF, LP3470A275DBVR achieves ~6.2 s reset delay; values beyond 10 µF are not characterized and may violate timing specifications. TI validates performance only up to 10 µF.