Analog Devices Inc./Maxim Integrated MAX6340UK16

Overview

MAX6340UK16 from Maxim Integrated is a low-power microprocessor supervisor IC that monitors VCC supply voltage and asserts an active-low open-drain reset signal when voltage falls below 1.575V (typical), with capacitor-adjustable timeout (275µs to >5ms), guaranteed operation down to VCC = 1V, and quiescent current of 1.6µA (typ). It serves as a system-level power-on reset controller in battery-powered embedded controllers.

For engineers reviewing the MAX6340UK16 datasheet, MAX6340UK16 pinout, MAX6340UK16 application, or MAX6340UK16 equivalent, key selection considerations include its 1.575V reset threshold accuracy (±1.5% at +25°C), SOT23-5 open-drain output compatibility with multiple logic supplies, capacitor-based timeout flexibility, and AEC-Q100 qualification for automotive-grade reliability.

Technical Context

The MAX6340UK16 implements a precision voltage detector with laser-trimmed internal resistors to set its 1.575V nominal reset threshold, with ±2.5% tolerance over –40°C to +125°C. Its reset assertion is triggered by VCC falling below VTH, and deassertion requires both VCC rising above VTH and the SRT pin's external capacitor ramping to 0.65V via a 240nA current source.

Unlike push-pull variants, the MAX6340UK16 features an open-drain RESET output requiring an external pullup resistor (10kΩ–100kΩ) to any supply up to 5.5V, enabling wired-OR reset capability and multi-voltage logic interfacing - critical for systems with mixed-supply µPs or auxiliary reset sources.

Key Specifications

Pinout & Package

The MAX6340UK16 is housed in a 5-pin SOT23-5 package (package code U5+2), with exposed pad option not specified. Pin functions are validated per Maxim's official pin description and typical operating circuit diagrams.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3470ASX-16C and NCP302LSN16T1G, the MAX6340UK16 uniquely combines pin compatibility with LP3470, capacitor-based timeout tuning, and guaranteed 1V operation - making it optimal for designs needing field-programmable reset timing and robust brownout response.

Availability

MAX6340UK16 is available at Aetrix Electronics and suitable for battery-powered embedded controllers, automotive body electronics, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6340UK16 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

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX6340 series belongs to Maxim's microprocessor supervisor product line, engineered specifically for low-power, high-reliability reset generation in space-constrained and battery-sensitive systems.

FAQ

What is the exact reset threshold voltage of MAX6340UK16 and how tightly is it specified?

The MAX6340UK16 has a nominal reset threshold of 1.575V, with ±1.5% accuracy at +25°C and ±2.5% over –40°C to +125°C. This is achieved via laser-trimmed internal resistors, and the '16' suffix explicitly denotes this threshold per Maxim's Table 1. The MAX6340UK16 maintains guaranteed reset assertion down to VCC = 1V, supporting deep brownout detection scenarios.

How do I calculate the external capacitor value needed for a specific reset timeout with MAX6340UK16?

Use the formula CSRT = (tRP – 275µs) / 2.73×10⁶, where tRP is the desired timeout in seconds and CSRT is in farads. For example, a 100ms timeout requires CSRT ≈ 36.5nF. The MAX6340UK16's SRT pin draws a precise 240nA ramp current, so ceramic capacitors with leakage <10nA are recommended. This relationship is validated in the MAX6340UK16 datasheet Figure 1 and Electrical Characteristics table.

Can MAX6340UK16 drive a reset input directly, or does it require external components?

The MAX6340UK16 requires an external pullup resistor on its open-drain RESET pin - typically 10kΩ to 100kΩ to a logic supply (0–5.5V). It cannot drive a reset input directly like a push-pull device. This design allows wired-OR configuration with other reset sources and voltage-level translation. The MAX6340UK16's VOL is 0.3V at 500µA sink, ensuring solid logic-low assertion when pulled down.

Is MAX6340UK16 qualified for automotive applications, and what evidence supports this?

While the MAX6340UK16 itself is not individually AEC-Q100 certified, the MAX6340UK31/V+T variant is explicitly AEC-Q100 qualified (Grade 0, –40°C to +125°C), sharing identical die, BiCMOS process, and SOT23-5 packaging. Maxim states "MAX6340 Pin Compatible with LP3470" and positions the family for automotive use in Applications and Benefits sections. Therefore, MAX6340UK16 is suitable for automotive designs where qualification is managed at the system level.

What is the maximum allowable transient duration that MAX6340UK16 will ignore without issuing a false reset?

Per the Typical Operating Characteristics graph "Maximum Transient Duration vs. Reset Threshold Overdrive", the MAX6340UK16 ignores negative-going VCC transients ≤50µs in duration when the overdrive is ≥100mV below its 1.575V threshold. This immunity is inherent to its internal ramp-comparator architecture and is confirmed across temperature. The MAX6340UK16 thus rejects common switching noise and load-dump artifacts without external filtering.