Texas Instruments LP3470IM5-2.93

Overview

LP3470IM5-2.93 from Texas Instruments (formerly National Semiconductor) is a micropower CMOS voltage supervisory IC designed to monitor VCC supply voltage in microprocessor systems and assert an open-drain active-low reset signal when voltage drops below 2.93 V. It features ±1% reset threshold accuracy over temperature, 16 µA typical quiescent current, guaranteed reset validity down to VCC = 0.5 V, and programmable reset timeout via external capacitor. Used in battery-powered instrumentation and embedded controllers requiring reliable power-on reset.

For engineers reviewing the LP3470IM5-2.93 datasheet, LP3470IM5-2.93 pinout, LP3470IM5-2.93 application, or LP3470IM5-2.93 equivalent, key selection considerations include reset threshold tolerance, SOT23-5 package compatibility, open-drain output drive capability, immunity to short VCC transients, and support for programmable reset timeout using a single external capacitor.

Technical Context

The LP3470IM5-2.93 implements a precision voltage comparator with hysteresis (35 mV typical) to detect VCC falling below 2.93 V and trigger reset assertion. Its internal circuitry guarantees valid reset output even at VCC as low as 0.5 V, enabling robust brownout detection during power ramp-down.

Reset timeout period (tRP) is fully programmable via external capacitor on SRT pin using tRP (ms) = 2000 × C1 (µF), supporting delay ranges from ~1 ms to >1 s. The open-drain Reset output requires an external pull-up resistor (recommended 20 kΩ) and sinks up to 10 mA while maintaining VOL ≤ 0.4 V at 4 mA load.

Key Specifications

Pinout & Package

LP3470IM5-2.93 is housed in a 5-pin SOT23-5 package (NS package MF05A, JEDEC MO-178), with 1.27 mm pitch, 2.9 mm × 1.6 mm footprint, and 1.1 mm max height. Pin 1 is marked with a dot or beveled edge.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G18DBVR and MAX6326UT29D3+, the LP3470IM5-2.93 uniquely supports precise 2.93 V supervision with user-defined reset hold time via capacitor, making it optimal for industrial and portable systems requiring both threshold accuracy and timing flexibility.

Availability

LP3470IM5-2.93 is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial PLC modules, medical handheld diagnostics, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LP3470IM5-2.93 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 acquired National Semiconductor in 2011 and maintains its precision analog portfolio, including voltage supervisors, with global manufacturing, testing, and quality infrastructure.

The LP3470IM5-2.93 belongs to National Semiconductor's Tiny Power-On Reset family, engineered for space-constrained, low-power embedded systems where accurate, programmable reset timing and minimal supply current are critical.

FAQ

What is the exact reset threshold voltage of LP3470IM5-2.93?

The LP3470IM5-2.93 has a nominal reset threshold voltage of 2.93 V, with ±1% accuracy over the full −40°C to +85°C operating temperature range. This value is factory-trimmed and specified in the Electrical Characteristics table under VRTH for the LP3470I grade. The hysteresis is 35 mV typical, ensuring stable transition behavior near the threshold.

How do I configure the reset timeout period for LP3470IM5-2.93?

To configure the reset timeout period for LP3470IM5-2.93, connect a capacitor (C1) between pin SRT (Pin 1) and GND. The timeout tRP in milliseconds equals 2000 × C1, where C1 is in microfarads. For example, a 100 nF (0.1 µF) capacitor yields a 200 ms timeout. Leaving SRT floating disables the timeout, causing reset to deassert immediately after VCC rises above 2.93 V.

What is the recommended pull-up resistor value for the LP3470IM5-2.93 Reset output?

The LP3470IM5-2.93 Reset output is open-drain and requires an external pull-up resistor. National Semiconductor recommends 20 kΩ to VCC as a typical value. The resistor must be between 680 Ω (to limit sink current <10 mA) and 68 kΩ (to overcome 1 µA max leakage). Values outside this range risk output malfunction or excessive power draw.

Does LP3470IM5-2.93 remain functional at very low supply voltages?

Yes, LP3470IM5-2.93 guarantees valid reset output down to VCC = 0.5 V. This means the device continues asserting reset even as the supply collapses far below its 2.93 V threshold, ensuring the host microcontroller remains held in reset until power is fully removed or recovered - a critical feature for data integrity in battery-backed systems.

Is LP3470IM5-2.93 compatible with the standard SOT23-5 footprint?

Yes, LP3470IM5-2.93 uses the industry-standard 5-pin SOT23-5 package (National Semiconductor package MF05A, JEDEC MO-178), with 1.27 mm lead pitch and 2.9 mm × 1.6 mm body dimensions. It is mechanically and solder-reflow compatible with common SOT23-5 footprints used in automated PCB assembly.