Analog Devices Inc./Maxim Integrated MAX6448UK46L+T

Overview

MAX6448UK46L+T from Maxim Integrated is a single-supply, fixed-threshold microprocessor supervisor IC with one extended-setup manual reset input (MR1) and one immediate-assertion manual reset input (MR2), 4.625V VCC reset threshold, 6.72s MR1 setup period, and open-drain active-low RESET output in 5-pin SOT23 package. It ensures reliable system reset during power-up, brownout, and user-initiated recovery in consumer and industrial embedded systems.

For engineers reviewing the MAX6448UK46L+T datasheet, MAX6448UK46L+T pinout, MAX6448UK46L+T application, or MAX6448UK46L+T equivalent, key selection criteria include its dual-mode manual reset architecture (extended + immediate), guaranteed reset assertion down to VCC = 1.0V, 6µA supply current, immunity to <100ns glitches on MR2, and compatibility with 3.3V/5V logic domains via open-drain RESET.

Technical Context

The MAX6448UK46L+T implements a precision bandgap-based voltage monitor for VCC with factory-trimmed 4.625V threshold (±130mV tolerance) and 60ppm/°C tempco. Its MR1 input requires a sustained low pulse of 6.72s (L-suffix) to trigger a 140ms–280ms one-shot RESET pulse, while MR2 responds immediately to a rising edge-debounced for 210ms-to assert RESET for the same timeout period.

This dual-reset-input architecture enables hierarchical system control: MR1 serves as a deliberate, tamper-resistant hard reset (e.g., service mode), while MR2 supports fast, event-driven actions like smart-card insertion detection or emergency interrupt escalation without requiring long button holds.

Key Specifications

Pinout & Package

Package: 5-pin SOT23 (U5+1), footprint compatible with industry-standard 5-lead SOT-23 land pattern (90-0174). RoHS-compliant, lead(Pb)-free, tape-and-reel packaging.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6447UK46L+T, the MAX6448UK46L+T offers open-drain flexibility for multi-rail systems; compared with TPS3808G33DBVR, it delivers unique dual-mode reset control essential for user-interface-rich embedded devices requiring both safe and responsive reset paths.

Availability

MAX6448UK46L+T is available at Aetrix Electronics and suitable for set-top boxes, DSL modems, and industrial HMI panels requiring stable component supply, long-term lifecycle support, and guaranteed automotive-grade temperature operation (-40°C to +85°C).

Supply support for MAX6448UK46L+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

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

The MAX6443–MAX6452 family was engineered specifically for robust, low-power microprocessor supervision in noise-prone consumer electronics and industrial equipment, emphasizing immunity to transients, flexible reset initiation, and guaranteed operation across wide voltage and temperature ranges.

FAQ

What is the exact reset threshold voltage for MAX6448UK46L+T?

The MAX6448UK46L+T has a factory-trimmed VCC reset threshold of 4.625V, with a guaranteed range of 4.50V to 4.75V at +25°C and ±130mV total tolerance over -40°C to +85°C. This value is defined by the "46" suffix per Table 1 in the datasheet and applies specifically to the VCC monitor channel - not RSTIN, which is absent in this variant.

How does the MR2 input on MAX6448UK46L+T differ from MR1?

The MR2 input on MAX6448UK46L+T is edge-triggered and responds immediately to a rising edge with a 140ms–280ms RESET pulse, debounced for 210ms to reject noise. In contrast, MR1 requires a sustained low-level pulse of exactly 6.72s (L-suffix) to initiate reset. MR2 enables fast event-driven resets (e.g., card detect), while MR1 enforces deliberate, secure reset initiation.

Can MAX6448UK46L+T operate with a 3.3V supply?

Yes, MAX6448UK46L+T operates over 1.0V to 5.5V, so it functions reliably at 3.3V. However, its 4.625V reset threshold means it monitors a 5V rail - not the 3.3V supply itself. When used in 3.3V systems, it must supervise a higher-voltage domain (e.g., 5V I/O rail) or be configured with an external divider on RSTIN (not applicable here, as MAX6448 lacks RSTIN).

What is the minimum pullup resistor value required for the open-drain RESET output of MAX6448UK46L+T?

The datasheet specifies a minimum 20kΩ pullup resistor to VCC for the open-drain RESET output of MAX6448UK46L+T. This ensures proper logic high level under worst-case sink current (3.2mA at VCC ≥ 4.25V) while limiting power consumption. Lower values increase drive strength but raise static current; higher values risk slow rise times in noisy environments.

Does MAX6448UK46L+T support AEC-Q100 qualification?

No, MAX6448UK46L+T is not AEC-Q100 qualified. Only specific variants in the MAX6443–MAX6452 family carry automotive qualification - notably MAX6444US16K/V+T (1.575V threshold, K-suffix, /V grade). The MAX6448UK46L+T is rated for industrial temperature range (-40°C to +85°C) but lacks the additional stress testing and documentation required for automotive use.