Analog Devices Inc./Maxim Integrated MAX6443US23L

Overview

MAX6443US23L from Maxim Integrated is a single-supply, fixed-threshold microprocessor reset supervisor IC with one extended-setup manual reset input (MR1), 2.313V VCC reset threshold, and 6.72s manual reset setup period. It features active-low push-pull RESET output, 6µA supply current, guaranteed valid reset down to VCC = 1.0V, and operates over –40°C to +85°C. It is used in consumer electronics such as DVD players to prevent spurious resets during front-panel button presses.

For engineers reviewing the MAX6443US23L datasheet, MAX6443US23L pinout, MAX6443US23L application, or MAX6443US23L equivalent, key selection considerations include its 2.313V factory-set VCC threshold, 6.72s MR1 hold-time requirement, SOT143-4 package compatibility, and immunity to <100ns glitches on MR1 - critical for reliable system-level power-up and brownout supervision.

Technical Context

The MAX6443US23L implements a precision bandgap-based voltage monitor for VCC with 2.313V ±0.075V threshold and 60ppm/°C tempco, ensuring stable reset assertion across industrial temperature range. Its internal 50kΩ MR1 pullup enables direct connection to momentary switches without external components.

Reset assertion follows dual-trigger logic: VCC falling below 2.313V initiates a 210ms (typ) timeout, while MR1 held low ≥6.72s triggers a one-shot 140ms (min) RESET pulse. The push-pull output drives µP reset inputs directly without external pullup, supporting valid logic states down to VCC = 1.0V.

Key Specifications

Pinout & Package

MAX6443US23L is housed in a 4-pin SOT143 package (pin pitch 0.95mm, body size 2.9mm × 1.3mm), optimized for space-constrained consumer PCBs. The package is RoHS-compliant and lead(Pb)-free (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6444US23L, MAX6443US23L eliminates external pullup components and reduces BOM count; compared with MAX6445UK23L, it saves PCB area and simplifies mechanical design by requiring only one front-panel switch - making it optimal for cost-sensitive, space-constrained consumer audio/video devices.

Availability

MAX6443US23L is available at Aetrix Electronics and suitable for DVD players, set-top boxes, and MP3 players requiring stable component supply with guaranteed long-term availability and industrial temperature support.

Supply support for MAX6443US23L 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, with emphasis on high-reliability industrial and consumer solutions.

The MAX6443–MAX6452 family was engineered specifically for robust microprocessor supervision in cost-sensitive consumer electronics, balancing ultra-low quiescent current, factory-trimmed accuracy, and extended manual reset immunity.

FAQ

What is the exact VCC reset threshold voltage for MAX6443US23L?

The MAX6443US23L has a factory-set VCC reset threshold of 2.313V, with guaranteed tolerance of ±0.075V over –40°C to +85°C. This value is defined by the "23" suffix per Table 1 in the datasheet and is trimmed during production to ensure precision without external calibration. The threshold remains stable with 60ppm/°C tempco, making MAX6443US23L suitable for 3.3V rail supervision where 2.313V provides adequate margin above typical brownout levels.

How does the 6.72s manual reset setup period (L-suffix) function in MAX6443US23L?

The "L" suffix in MAX6443US23L specifies a 6.72s minimum MR1 low-pulse width required to trigger a one-shot RESET assertion. This extended setup period is implemented via an internal RC timer and prevents false resets from accidental or brief switch closures. Once MR1 is held low ≥6.72s, RESET pulses low for 140ms (min). MR1 must return high and be reasserted to initiate another reset - a feature critical for reliable user-initiated recovery in consumer devices like DVD players.

Does MAX6443US23L support operation below 1.8V VCC?

Yes, MAX6443US23L is fully specified down to VCC = 1.0V, with guaranteed valid RESET output logic state and functional reset assertion. At VCC = 1.0V, the push-pull output maintains VOL ≤ 0.3V when sinking 50µA, ensuring compatibility with low-voltage µPs. However, RESET deassertion (VOH) is not guaranteed below VCC = 1.8V; thus, MAX6443US23L is appropriate for brownout detection but not for full reset signaling in sub-1.8V systems unless verified per application.

What package type and footprint does MAX6443US23L use?

MAX6443US23L uses a 4-pin SOT143 package (outline 21-0052, land pattern 90-0183), measuring 2.9mm × 1.3mm with 0.95mm pin pitch. It is lead(Pb)-free (+T suffix) and RoHS-compliant. The pinout is GND (1), RESET (2), MR1 (3), VCC (4) in top-view orientation. This compact footprint enables high-density placement in portable consumer electronics where board space is constrained, such as MP3 players and cable modems.

Can MAX6443US23L monitor voltages other than VCC?

No, MAX6443US23L monitors only the VCC supply pin - it is a single-fixed-threshold supervisor without RSTIN input. Devices like MAX6449US23L or MAX6452US23L provide adjustable RSTIN monitoring down to 0.63V, but MAX6443US23L is strictly limited to its factory-set 2.313V VCC threshold. For dual-supply monitoring or custom thresholds, engineers must select from the MAX6449–MAX6452 variants, not MAX6443US23L.