Analog Devices Inc./Maxim Integrated MAX6450UT23L+

Overview

MAX6450UT23L+ from Maxim Integrated is a dual-supply microprocessor supervisor IC with one fixed-threshold (2.313V) and one adjustable-threshold (0.63V reference) voltage monitor, two extended-setup manual reset inputs (MR1/MR2), push-pull active-low RESET output, and 6.72s minimum manual reset pulse width - designed for reliable system reset in set-top boxes, DVD players, and industrial equipment.

For engineers reviewing the MAX6450UT23L+ datasheet, MAX6450UT23L+ pinout, MAX6450UT23L+ application, or MAX6450UT23L+ equivalent, key selection considerations include its dual-monitor architecture, 6.72s extended MR setup period to prevent nuisance resets, guaranteed RESET assertion down to VCC = 1.0V, and SOT23-6 lead-free package compatibility with high-reliability embedded power sequencing.

Technical Context

The MAX6450UT23L+ integrates two independent reset comparators: one factory-trimmed at 2.313V ±0.075V for VCC monitoring, and one precision 0.630V ±0.020V reference for external resistor-divider-based RSTIN monitoring. Its dual MR1/MR2 inputs require simultaneous low assertion for ≥6.72s to trigger a 140ms min one-shot RESET pulse.

Internal 50kΩ pullups on MR1 and MR2 eliminate external components; RESET remains asserted for 210ms typical after all monitored supplies exceed thresholds. The device operates from 1.0V to 5.5V, draws only 6µA at 3.6V, and guarantees valid logic states across –40°C to +85°C.

Key Specifications

Pinout & Package

MAX6450UT23L+ is housed in a RoHS-compliant, lead-free 6-pin SOT23 package (U6-1 outline, 90-0175 land pattern), optimized for space-constrained PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6449UT23L+, MAX6450UT23L+ adds MR2 for dual-input safety-critical reset; compared with MAX6452UT23L+, it offers push-pull RESET to reduce component count and improve noise margin in single-supply designs.

Availability

MAX6450UT23L+ is available at Aetrix Electronics and suitable for set-top boxes, DVD players, industrial HMIs, and medical devices requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX6450UT23L+ 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 management, sensing, and interface applications in industrial, automotive, and consumer markets.

The MAX6443–MAX6452 family delivers robust µP supervision with extended manual reset timing and dual-threshold monitoring - engineered specifically for reliability-critical consumer and industrial electronics where nuisance resets must be eliminated.

FAQ

What is the exact reset threshold voltage for VCC on the MAX6450UT23L+?

The MAX6450UT23L+ has a factory-trimmed VCC reset threshold of 2.313V, with a tolerance of ±0.075V over temperature. This value is confirmed in Table 1 of the datasheet under the "23" suffix designation and applies specifically to the MAX6450UT23L+ variant - not inferred from adjacent models. The threshold is guaranteed across –40°C to +85°C with 60ppm/°C tempco.

Does the MAX6450UT23L+ support adjustable voltage monitoring, and how is it implemented?

Yes, the MAX6450UT23L+ supports adjustable voltage monitoring via its RSTIN pin, which references an internal 0.630V ±0.020V precision bandgap. An external resistor divider connects between the monitored voltage and ground, with RSTIN tied to the divider midpoint. The formula VMON-TH = 0.63 × (R1 + R2)/R2 determines the trip point - enabling supervision of any voltage ≥0.63V without trimming.

What is the function of the two manual reset inputs (MR1 and MR2) on the MAX6450UT23L+?

Both MR1 and MR2 on the MAX6450UT23L+ are active-low inputs requiring simultaneous assertion for ≥6.72s (L suffix) to trigger a 140ms min one-shot RESET pulse. They feature internal 50kΩ pullups to VCC, eliminating external resistors. This dual-input requirement prevents accidental resets and supports safety-critical or service-mode functions like factory reset or diagnostic entry.

Is the RESET output of the MAX6450UT23L+ push-pull or open-drain, and what are the implications?

The MAX6450UT23L+ features an active-low push-pull RESET output, meaning it actively drives low and high states without requiring an external pullup resistor. This reduces BOM count and improves noise immunity compared to open-drain variants. VOH is guaranteed at 0.8×VCC for loads up to 800µA, making it compatible with standard CMOS µP reset inputs across 1.8V–5.5V supply ranges.

How does the MAX6450UT23L+ ensure reliable operation during brownout conditions?

The MAX6450UT23L+ guarantees valid RESET assertion and logic states down to VCC = 1.0V, with ICC remaining at just 6µA at 3.6V. Its reset timeout period (140ms min) holds the µP in reset until all monitored supplies - including VCC and the externally divided RSTIN voltage - exceed their respective thresholds and remain stable for the full timeout duration, preventing premature release during marginal supply conditions.