Analog Devices Inc./Maxim Integrated MAX6422XS31+T

Overview

MAX6422XS31+T from Analog Devices is a low-power, active-high push-pull microprocessor reset supervisor IC that monitors VCC from 1.6V to 5.5V and asserts RESET when voltage falls below 3.075V (typical threshold). It features capacitor-adjustable reset timeout (3.0–5.75ms with 1500pF), guaranteed valid operation down to VCC = 1V, and consumes only 1.6µA typical quiescent current. It is used in battery-powered controllers and portable equipment for reliable power-on reset sequencing.

For engineers reviewing the MAX6422XS31+T datasheet, MAX6422XS31+T pinout, MAX6422XS31+T application, or MAX6422XS31+T equivalent, key selection criteria include its active-high push-pull output, SC70-4 package, ±2.5% reset threshold accuracy over –40°C to +125°C, immunity to short VCC transients, and compatibility with µP reset inputs requiring high-asserted logic during brownout recovery.

Technical Context

The MAX6422XS31+T implements a precision voltage detector with laser-trimmed internal resistors to set its 3.075V nominal reset threshold (suffix "31"), with ±2.5% tolerance across –40°C to +125°C. Its reset timeout is generated by a 240nA internal ramp current charging an external capacitor (SRT-to-GND), comparing the resulting voltage against a stable 0.65V reference.

Unlike open-drain variants, the MAX6422XS31+T drives RESET high actively (VOH ≥ 0.8×VCC) and low actively (VOL ≤ 0.4V at 3.2mA sink), eliminating need for external pull-up. It guarantees functional reset assertion even as VCC drops to 1V, and exhibits immunity to negative-going VCC transients ≤50µs when overdrive is ≤100mV below VTH.

Key Specifications

Pinout & Package

MAX6422XS31+T is housed in a 4-pin SC70-4 package (outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm, with gull-wing leads and RoHS-compliant lead-free finish ("+T" suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6422XS31+T, the MAX6422US31+T offers identical functionality in a mechanically distinct package, while the TLV803EB31DBZR trades push-pull drive for lower unit cost and added external component dependency-neither is pin-compatible, but both serve overlapping supervisory roles in 3.0V–3.3V systems.

Availability

MAX6422XS31+T is available at Aetrix Electronics and suitable for battery-powered portable controllers, automotive body control modules, and industrial programmable logic controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6422XS31+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.

The MAX6421–MAX6426 family delivers ultra-low-power, capacitor-programmable reset supervision for space-constrained, battery-sensitive, and thermally demanding embedded systems-designed specifically for robust µP monitoring where precision, reliability, and minimal footprint are critical.

FAQ

What is the exact reset threshold voltage of MAX6422XS31+T?

The MAX6422XS31+T has a nominal reset threshold of 3.075V, with guaranteed minimum of 2.998V and maximum of 3.152V at –40°C to +125°C. This is defined by the "31" suffix per Table 1 in the datasheet and confirmed by laser-trimming during manufacturing. The MAX6422XS31+T maintains this accuracy across its full operating temperature range, enabling reliable brownout detection in 3.0V–3.3V systems.

Does MAX6422XS31+T require an external pull-up resistor on the RESET pin?

No, MAX6422XS31+T does not require an external pull-up resistor because it features an active-high push-pull output stage. The RESET pin actively drives high (≥0.8×VCC) and low (≤0.4V at 3.2mA sink), providing full logic-level compliance without external components. This distinguishes MAX6422XS31+T from open-drain variants like MAX6423XS31+T and simplifies PCB layout.

How is the reset timeout period set for MAX6422XS31+T?

The reset timeout period for MAX6422XS31+T is set by connecting an external capacitor (CSRT) between the SRT pin and GND. Using CSRT = 1500pF yields a typical timeout of 4.375ms (range 3.00–5.75ms). The relationship is tRP = 2.73×10⁶ × CSRT + 275µs, where tRP is in seconds and CSRT in farads. MAX6422XS31+T relies on a precision 240nA internal ramp current for stable timing.

Can MAX6422XS31+T operate reliably at VCC = 1.2V?

Yes, MAX6422XS31+T guarantees valid RESET assertion and deassertion down to VCC = 1.0V, including at 1.2V. Its internal circuitry remains functional, and output drive specifications (e.g., VOL ≤ 0.3V at 500µA sink) are maintained. This capability is critical for graceful shutdown sequencing in energy-harvesting and ultra-low-power systems where supply may decay slowly below 1.8V.

What package type and dimensions does MAX6422XS31+T use?

MAX6422XS31+T uses the SC70-4 package (package code X4+1, outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm with gull-wing leads. It is RoHS-compliant and supplied in tape-and-reel format ("+T" suffix). This compact footprint supports high-density layouts in portable and wearable electronics where board space is constrained.