Analog Devices Inc./Maxim Integrated MAX6422XS46+

Overview

MAX6422XS46+ from Maxim Integrated is a low-power microprocessor supervisor IC that monitors VCC supply voltage and asserts an active-high push-pull RESET signal when voltage falls below 4.625V (±2.5% over temperature), with capacitor-adjustable reset timeout and guaranteed operation down to VCC = 1V. It features 1.6µA typical quiescent current, 4-pin SC70 package, and is used in battery-powered controllers and portable medical instruments for reliable power-on reset sequencing.

For engineers reviewing the MAX6422XS46+ datasheet, MAX6422XS46+ pinout, MAX6422XS46+ application, or MAX6422XS46+ equivalent, this page delivers verified electrical parameters, exact pin functions, real-world use cases, and validated alternative parts for embedded system design and BOM optimization.

Technical Context

The MAX6422XS46+ implements a precision bandgap-based voltage monitor with laser-trimmed threshold and internal 240nA ramp current source for capacitor-controlled timeout. Its active-high push-pull output drives µP reset inputs directly without external pull-up, supporting logic compatibility across 1.6V–5V systems.

It uses a voltage-ramp comparator architecture where SRT pin voltage rises linearly (dV/dt = I/C) until reaching 0.65V to deassert RESET; reset assertion occurs within 80µs of VCC falling below threshold, with hysteresis of 4×VTH (≈18.5mV at 4.625V).

Key Specifications

Pinout & Package

MAX6422XS46+ is housed in a 4-pin SC70 package (2.0mm × 1.25mm × 0.9mm), optimized for space-constrained portable designs. Pin 1 is SRT (Set Reset Timeout), Pin 2 is GND, Pin 3 is RESET (active-high push-pull), and Pin 4 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6421XS46+, the MAX6422XS46+ provides active-high reset signaling without external components, while TLV803EB46DBZR trades adjustability for lower IQ and smaller size - making MAX6422XS46+ optimal for designs requiring configurable timing and direct µP interface.

Availability

MAX6422XS46+ is available at Aetrix Electronics and suitable for battery-powered medical instruments, automotive body control modules, industrial handheld terminals, and smart energy meters requiring stable component supply, long-lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6422XS46+ 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 demanding industrial, automotive, and medical applications, with emphasis on reliability, low power, and integration.

The MAX6421–MAX6426 family was engineered specifically for ultra-low-power microprocessor supervision in space- and energy-constrained systems, delivering accurate voltage monitoring with user-configurable reset timing in miniature packages.

FAQ

What is the exact reset threshold voltage of the MAX6422XS46+ and how does it vary with temperature?

The MAX6422XS46+ has a nominal reset threshold of 4.625V, with ±2.5% tolerance over the full -40°C to +125°C operating range. This is confirmed in the Electrical Characteristics table under "VCC Reset Threshold Accuracy" and correlates to suffix "46" per Table 1. The normalized threshold drift versus temperature is less than ±0.5% across the range, as shown in Typical Operating Characteristic toc08.

Can the MAX6422XS46+ operate reliably when VCC drops below 1.6V, and what happens to the RESET output?

Yes, the MAX6422XS46+ guarantees valid RESET output down to VCC = 1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Below 1.0V, output drive capability degrades; however, for VCC ≥ 1.0V, the active-high push-pull RESET maintains VOH ≥ 0.8×VCC and VOL ≤ 0.4V, ensuring robust logic levels into standard CMOS inputs. The MAX6422XS46+ datasheet explicitly states "Guaranteed Reset Valid to VCC = 1V".

How do I calculate the SRT capacitor value needed for a 4.5ms reset timeout with the MAX6422XS46+?

Use the formula tRP = (2.73 × 10⁶) × CSRT + 275µs, solving for CSRT in farads. For tRP = 4.5ms = 0.0045s: CSRT = (0.0045 − 0.000275) / 2.73×10⁶ ≈ 1550pF. A standard 1500pF ceramic capacitor (low-leakage, X7R or C0G) yields ~4.375ms timeout, matching the "4.375" value in the tRP row of the Electrical Characteristics table for CSRT = 1500pF.

Is the MAX6422XS46+ pin-compatible with other devices in the MAX642x family, and which pins differ?

Yes, the MAX6422XS46+ shares identical 4-pin SC70 pinout with MAX6421XS46+ and MAX6423XS46+. Pin 1 = SRT, Pin 2 = GND, Pin 3 = RESET, Pin 4 = VCC. The only functional difference is RESET polarity: MAX6422XS46+ outputs active-high, while MAX6421XS46+ is active-low and MAX6423XS46+ is open-drain - requiring no PCB change but possible firmware or logic-level adaptation.

Does the MAX6422XS46+ require any external components beyond the SRT capacitor for basic operation?

No. Beyond the SRT timing capacitor, the MAX6422XS46+ requires no external resistors, diodes, or pull-ups. Its active-high push-pull RESET output drives µP reset inputs directly. A 100kΩ pullup resistor between RESET and VCC is recommended only if valid logic must be maintained as VCC falls below 1.0V - per Figure 4 in the datasheet - but is not required for standard operation.