Analog Devices Inc./Maxim Integrated MAX6340UK29/V+T

Overview

MAX6340UK29/V+T from Analog Devices is a low-power microprocessor supervisor IC with open-drain active-low reset output, 2.925V nominal reset threshold (±2.5% over temperature), capacitor-adjustable reset timeout (275µs to 5.75ms), and guaranteed operation down to VCC = 1V. It monitors supply voltage in battery-powered embedded controllers and automotive systems requiring precise brownout detection and flexible reset timing.

For engineers reviewing the MAX6340UK29/V+T datasheet, MAX6340UK29/V+T pinout, MAX6340UK29/V+T application, or MAX6340UK29/V+T equivalent, key selection criteria include its 5-pin SOT23-5 open-drain reset architecture, AEC-Q100 qualification (per /V+T variant), 1.6µA typical quiescent current, and compatibility with external pullup voltages up to 5.5V.

Technical Context

The MAX6340UK29/V+T implements a precision voltage-monitoring circuit with laser-trimmed internal resistors to set its 2.925V reset threshold, coupled with a 240nA constant-current source charging an external capacitor on the SRT pin to generate the reset timeout delay. Its open-drain RESET output requires an external pullup and remains asserted low until the SRT capacitor ramps to 0.65V after VCC exceeds the threshold.

It operates across –40°C to +125°C, supports supply voltages from 1.0V to 5.5V, and features immunity to short VCC transients-e.g., a 100mV negative-going glitch lasting ≤50µs typically does not trigger reset. The device is fabricated in BiCMOS process and contains 295 transistors.

Key Specifications

Pinout & Package

MAX6340UK29/V+T is housed in a 5-pin SOT23-5 package with exposed pad (not electrically connected). Pin 3 is internally unconnected (N.C.) and must be left floating or tied to GND per layout best practice.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP302LSN29T1G and TLV809EC29DBVR, the MAX6340UK29/V+T uniquely combines AEC-Q100 qualification, capacitor-adjustable timeout, and guaranteed 1V operation-making it the only option for automotive or industrial designs requiring both timing flexibility and robustness across extended temperature and voltage ranges.

Availability

MAX6340UK29/V+T is available at Aetrix Electronics and suitable for automotive body control modules, portable medical devices, industrial PLCs, smart energy meters, and battery-powered instrumentation requiring stable component supply with full lifecycle support.

Supply support for MAX6340UK29/V+T 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The MAX6340 series belongs to Analog Devices' precision voltage supervisor product line, designed specifically for mission-critical embedded systems demanding accurate reset thresholds, ultra-low power, and automotive-grade reliability.

FAQ

What is the exact reset threshold voltage of MAX6340UK29/V+T and how does it vary with temperature?

The MAX6340UK29/V+T has a nominal reset threshold of 2.925V, with accuracy of ±1.5% at +25°C and ±2.5% over the full –40°C to +125°C operating range. This is confirmed in the Electrical Characteristics table under "VCC Reset Threshold Accuracy" and validated by the "Normalized Reset Threshold vs. Temperature" plot (toc08), which shows drift within ±0.5% across temperature. The /V+T suffix denotes AEC-Q100 qualification, reinforcing thermal stability compliance.

Can MAX6340UK29/V+T drive a reset input directly without an external pullup resistor?

No - the MAX6340UK29/V+T features an open-drain RESET output and requires an external pullup resistor (typically 10kΩ–100kΩ) to a logic-compatible voltage (0–5.5V). Without it, the RESET line floats and cannot assert a valid logic high. The datasheet explicitly states: "Connect an external pullup resistor to any supply from 0 to 5.5V" and warns that improper sizing may cause false resets or slow rise times.

How is the reset timeout period calculated for MAX6340UK29/V+T, and what capacitor value yields ~4.375ms?

The reset timeout tRP is calculated as tRP = (2.73 × 10⁶) × CSRT + 275µs, where tRP is in seconds and CSRT in farads. For tRP = 4.375ms, solving gives CSRT ≈ 1500pF - matching the datasheet's typical value (tRP = 4.375ms at CSRT = 1500pF). Ceramic capacitors with <10nA leakage are required; X7R or C0G types are recommended per the "Selecting a Reset Capacitor" section.

Is MAX6340UK29/V+T pin-compatible with other supervisors like LP3470?

Yes - the MAX6340UK29/V+T is explicitly stated as pin-compatible with the LP3470 in the Benefits and Features section. Both use 5-pin SOT23-5 packages with identical pinout (VCC, GND, N.C., SRT, RESET), enabling drop-in replacement in existing LP3470 designs without PCB modification, provided the reset threshold and timeout requirements align.

Does MAX6340UK29/V+T support operation below 1.6V supply, and what is the minimum functional VCC?

Yes - the MAX6340UK29/V+T operates down to VCC = 1.0V, with guaranteed reset assertion validity to 1.0V (not just 1.6V). The Absolute Maximum Ratings specify VCC down to –0.3V, and the Electrical Characteristics table lists parameters at VCC = 1.0V (e.g., RESET leakage, VOL). The "Guaranteed Reset Valid to VCC = 1V" feature is highlighted in the Benefits section and confirmed in the Detailed Description.