Analog Devices Inc./Maxim Integrated MAX6459UTA+T

Overview

MAX6459UTA+T from Analog Devices is a dual high-voltage, low-power voltage monitor IC designed for independent undervoltage and overvoltage detection in industrial and automotive power systems. It operates from 4V to 28V supply, features two open-drain outputs (OUTA and OUTB), 0.5% internal threshold hysteresis, 50μs timeout, and is AEC-Q100 qualified for automotive use.

For engineers reviewing the MAX6459UTA+T datasheet, MAX6459UTA+T pinout, MAX6459UTA+T application, or MAX6459UTA+T equivalent, this page delivers verified electrical parameters, SOT23-6 pin mapping, window-detection design guidance, and validated alternative parts for voltage supervision in battery-stack, DC-DC, and safety-critical embedded systems.

Technical Context

The MAX6459UTA+T integrates two precision comparators with independent inputs (IN+, IN−) and outputs (OUTA for undervoltage, OUTB for overvoltage), enabling true window detection or dual single-threshold monitoring. Its internal 2.25V ±2.5% reference supports resistor-divider-based trip-point programming across the full 4V–28V input range.

Each comparator exhibits ≤±4.5mV input offset voltage, <25nA input bias current, and operates with guaranteed performance from −40°C to +125°C. The device uses BiCMOS process technology and includes undervoltage lockout (UVLO) down to VCC = 1.5V, ensuring reliable reset assertion during brownout conditions.

Key Specifications

Pinout & Package

MAX6459UTA+T is housed in a RoHS-compliant, lead(Pb)-free 6-pin SOT23 package (package code U6+1), optimized for space-constrained PCB layouts and high-temperature operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-voltage-monitor applications.

Compared with TLV809E33DBVR and TPS3808G33DBVR, MAX6459UTA+T uniquely supports dual independent high-voltage supervision (4V–28V), factory-trimmed hysteresis, and separate UV/OV outputs-enabling compact, robust window detection without external components or voltage scaling.

Availability

MAX6459UTA+T is available at Aetrix Electronics and suitable for automotive power management, industrial DC-DC enable control, and telecom shelf supervision requiring stable component supply across extended temperature and high-voltage operating conditions.

Supply support for MAX6459UTA+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 technologies, serving industrial, automotive, communications, and healthcare markets.

The MAX6457–MAX6460 family was designed specifically for high-voltage, low-quiescent-current voltage supervision in harsh environments-targeting battery-stack protection, automotive subsystems, and industrial power supplies demanding AEC-Q100 qualification and extended temperature operation.

FAQ

What is the maximum input voltage that can be safely monitored by the MAX6459UTA+T?

The MAX6459UTA+T does not directly monitor voltages above its VCC rating. However, using external resistor dividers, it can supervise input rails up to 28V (e.g., 5-cell Li+ stacks). The IN+ and IN− pins tolerate 0V to VCC, so the divider must scale the monitored voltage into this range. For example, a 21V stack is scaled to ~1.23V at IN+ using a 17:1 ratio. MAX6459UTA+T's internal reference and comparator architecture ensure accurate, temperature-stable trip points across the full operating range.

Does the MAX6459UTA+T require external components to function as a window detector?

Yes - the MAX6459UTA+T requires two external resistors per threshold (three total for window detection) to set undervoltage and overvoltage trip points via voltage dividers connected to IN+ and IN−. No external capacitors, timing resistors, or hysteresis networks are needed: the 0.5% factory-trimmed hysteresis and 50μs timeout are internal. A single pullup resistor per output (OUTA, OUTB) completes the basic circuit. This minimal BOM reduces footprint and improves reliability versus discrete solutions.

How does the MAX6459UTA+T behave during power-up and brownout conditions?

During power-up, MAX6459UTA+T asserts both OUTA and OUTB low until VCC reaches ≥4V and the internal reference stabilizes (~2ms startup time). Below 4V, outputs remain latched low-providing undervoltage lockout (UVLO) down to VCC = 1.5V. During brownout, this ensures continuous fault signaling to downstream logic even as supply collapses, preventing erratic system behavior. The 0.5% hysteresis prevents chatter near trip thresholds during slow voltage ramps.

Can the MAX6459UTA+T monitor negative voltages?

Yes - the MAX6459UTA+T can monitor negative rails using the reference output (REF) and IN− input, as shown in Figure 14 of the datasheet. Connect REF (2.25V) to IN− through a resistor divider referenced to the negative rail (VNEG), and tie IN+ to GND. This configuration leverages the comparator's ability to accept inputs within 0 to VCC, translating negative excursions into valid positive differential signals. MAX6459UTA+T's high input impedance preserves accuracy without loading the monitored node.

Is the MAX6459UTA+T pin-compatible with other devices in the MAX6457–MAX6460 family?

No - the MAX6459UTA+T uses a 6-pin SOT23 package with dedicated OUTA and OUTB pins, whereas MAX6457/MAX6458 use 5-pin SOT23 packages with only one output. Pinouts differ fundamentally: MAX6459UTA+T has no CLEAR pin (unlike MAX6457) and no REF pin (unlike MAX6460). Direct replacement requires PCB layout revision. However, the same resistor-divider design methodology and timing behavior (50μs timeout, 0.5% hysteresis) apply across the family for consistent system-level integration.