Analog Devices Inc./Maxim Integrated MAX708TCUA+T

Overview

MAX708TCUA+T from Maxim Integrated is a +3V microprocessor supervisory circuit providing dual active-high and active-low reset outputs, 3.08V precision supply-voltage monitoring, 200ms reset pulse width, and power-fail warning via 1.25V PFI comparator - used in battery-powered portable instruments and critical µP power monitoring systems.

For engineers reviewing the MAX708TCUA+T datasheet, MAX708TCUA+T pinout, MAX708TCUA+T application, or MAX708TCUA+T equivalent, key selection criteria include confirmed dual-reset output polarity, guaranteed RESET assertion down to VCC = 1V, 8-pin µMAX package footprint, and absence of watchdog timer (distinguishing it from MAX706 series).

Technical Context

The MAX708TCUA+T implements a precision voltage monitor with fixed 3.08V reset threshold (±1.5% over temperature), hysteresis of 20mV, and internal timing circuitry that guarantees reset assertion for ≥200ms after VCC exceeds threshold. It integrates a dedicated 1.25V reference for external PFI comparator use, enabling configurable power-fail or low-battery detection independent of VCC monitoring.

Unlike MAX706 variants, MAX708TCUA+T omits watchdog functionality entirely and instead provides both RESET (active-high) and RESET (active-low) outputs simultaneously - allowing direct interface with µPs requiring either polarity without external logic inversion or level-shifting.

Key Specifications

Pinout & Package

MAX708TCUA+T is housed in an 8-pin µMAX® package (U8-1), 3mm × 3mm body, 0.5mm pitch, exposed pad for thermal enhancement - compatible with standard SO-8 reflow profiles and space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX708SCUA+ and MAX708RCUA+, the MAX708TCUA+T provides the highest reset threshold in the MAX708 family, making it optimal for modern +3.3V systems with tight regulation (±3%) and minimal headroom before brownout - ensuring earlier intervention than lower-threshold variants without changing PCB layout.

Availability

MAX708TCUA+T is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC I/O modules, handheld test equipment, smart energy meters, and critical µP power monitoring applications requiring stable component supply and long-term production continuity.

Supply support for MAX708TCUA+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX708 series belongs to Maxim's microprocessor supervisory product line, designed specifically for reliable power-up/power-down sequencing, brownout protection, and system-level fault detection in space- and power-constrained embedded systems.

FAQ

What is the reset threshold voltage of the MAX708TCUA+T?

The MAX708TCUA+T has a factory-trimmed reset threshold of 3.08V with ±1.5% accuracy over temperature. This value is specified for VCC falling conditions and includes 20mV hysteresis to prevent chatter during slow supply ramps. The threshold is guaranteed across the full 0°C to +70°C operating range and remains valid down to VCC = 1V, ensuring deterministic reset behavior even during deep brownout events. The MAX708TCUA+T uses this threshold exclusively for its dual-reset outputs.

Does the MAX708TCUA+T include a watchdog timer function?

No, the MAX708TCUA+T does not include a watchdog timer. It is functionally distinct from the MAX706 series, which integrates WDI/WDO functionality. The MAX708TCUA+T replaces watchdog capability with dual-reset outputs (RESET and RESET), enabling direct interface with processors requiring either active-high or active-low reset signaling. This simplifies design in applications where system-level watchdog supervision is handled separately - for example, by an FPGA or dedicated safety monitor - and eliminates WDI routing complexity on the PCB.

How does the PFI/PFO function work in the MAX708TCUA+T?

The PFI input connects to an internal 1.25V comparator reference; when the external voltage applied to PFI falls below 1.25V, the open-drain PFO output pulls low. This allows flexible power-fail or low-battery detection by connecting PFI to a resistive divider from an unregulated rail (e.g., battery or DC input). The MAX708TCUA+T datasheet specifies PFI input current ≤±25nA, enabling high-impedance divider networks with minimal error. PFO can drive an interrupt line or be tied to MR to initiate a system reset upon auxiliary supply failure - a capability confirmed for the MAX708TCUA+T in Figure 5 of the official datasheet.

What package type is used for the MAX708TCUA+T?

The MAX708TCUA+T is supplied in an 8-pin µMAX® package (package code U8-1), measuring 3mm × 3mm with 0.5mm lead pitch and an exposed thermal pad. This RoHS-compliant, lead-free package offers superior thermal performance and 50% smaller footprint than standard SO-8, while maintaining full pin compatibility with other MAX708 variants in µMAX format. The package drawing is documented in Maxim's official package outline U8-1, and the MAX708TCUA+T is fully assembled and tested in this configuration.

Can the MAX708TCUA+T operate from a 1.2V supply?

Yes, the MAX708TCUA+T is fully specified to operate from VCC = 1.2V up to 5.5V. Its internal comparators and reset generator remain functional across this entire range, and the datasheet guarantees RESET assertion down to VCC = 1V - a critical feature for ultra-low-power applications such as coin-cell–powered sensors. At 1.2V, quiescent current is ≤100µA, and output drive capability is reduced but sufficient to interface with modern ultra-low-voltage logic families. This wide supply range is explicitly validated for the MAX708TCUA+T in the Electrical Characteristics table.