Analog Devices Inc./Maxim Integrated MAX6708TKA+T

Overview

MAX6708TKA+T from Maxim Integrated is a precision microprocessor supervisory IC in an 8-pin SOT23 package, providing dual active-low/high push-pull reset outputs, a 0.62V power-fail comparator input (PFI), and a dedicated power-fail output (PFO). It monitors +3.0V supply voltage (threshold = 3.08V, ±3% over -40°C to +125°C), features 140ms reset timeout delay, and guarantees valid reset operation down to VCC = 1V. It is used in critical µP power monitoring for industrial controllers and telecom infrastructure.

For engineers reviewing the MAX6708TKA+T datasheet, MAX6708TKA+T pinout, MAX6708TKA+T application, or MAX6708TKA+T equivalent, this page delivers verified functional identity, confirmed pin roles, exact reset threshold and timing specs, real-world use cases in white goods and networking equipment, and two validated alternative parts with documented differences in watchdog capability and output configuration.

Technical Context

The MAX6708TKA+T implements a dual-output reset architecture: one active-low and one active-high push-pull RESET signal derived from the same internal reset generator. Unlike MAX6704, it omits the watchdog timer entirely - no WDI or WDO pins are present or functional. Its PFI input accepts voltages down to 0.62V with 6mV hysteresis, enabling precise early-warning power-fail detection via external resistor dividers.

It uses a BiCMOS process (716 transistors) and operates across -40°C to +125°C. The device asserts reset when VCC falls below its factory-trimmed 3.08V threshold (±3% over full temperature range), with guaranteed 12µs propagation delay and immunity to short VCC transients. Reset remains asserted for 140ms after VCC recovers above threshold.

Key Specifications

Pinout & Package

MAX6708TKA+T is housed in an 8-pin SOT23 package (package code K8+2, outline 21-0078), measuring 2.9mm × 1.6mm × 1.1mm, RoHS-compliant (lead-free, indicated by "+T" suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6704TKA+T, MAX6708TKA+T removes watchdog circuitry to reduce quiescent current (6µA vs. 9µA) and simplify layout, while retaining identical reset accuracy and PFI/PFO functionality. Against TPS3808G30DBVR, MAX6708TKA+T delivers integrated power-fail signaling and dual-polarity reset - eliminating two external components and enabling advanced power-management sequences.

Availability

MAX6708TKA+T is available at Aetrix Electronics and suitable for industrial controllers, telecom power management, and white goods requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6708TKA+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 demanding industrial, automotive, and communications applications.

The MAX6701–MAX6708 family targets microprocessor power supervision in space-constrained, high-reliability systems - delivering integrated reset, power-fail warning, and manual reset in ultra-small SOT23 packages.

FAQ

What is the exact reset threshold voltage of MAX6708TKA+T and how tightly is it specified?

The MAX6708TKA+T has a factory-trimmed reset threshold of 3.08V, with guaranteed tolerance of ±3% over the full operating temperature range (-40°C to +125°C). This specification is confirmed in the Electrical Characteristics table under "VCC Reset Threshold" for the "T" suffix variant. The threshold is laser-trimmed during production and does not require external calibration. At +25°C, typical deviation is ±1.5%, but design must accommodate the worst-case ±3% bound.

Does MAX6708TKA+T include a watchdog timer function?

No, MAX6708TKA+T does not include a watchdog timer. It is explicitly defined in the datasheet as "the same as the MAX6704 but without the watchdog timer function." Pin 6 is designated N.C. (no connection), and neither WDI nor WDO functionality is implemented. This distinguishes it from MAX6704TKA+T (which has WDI but no WDO) and MAX6705–MAX6707 variants (which include both WDI and WDO).

What are the voltage and timing specifications for the PFI and PFO pins on MAX6708TKA+T?

The PFI pin has a precise 618mV typical threshold (593–642mV over -40°C to +125°C) with 6mV hysteresis, referenced to an internal bandgap. The PFO pin is an active-low push-pull output that asserts within 1µs of PFI crossing threshold. It sinks 200µA at VCC ≥ 1.8V (VOL ≤ 0.3V) and 1.2mA at VCC ≥ 2.55V (VOL ≤ 0.3V), enabling direct drive of µP interrupts or FPGA inputs without external buffers.

How does the dual-reset output configuration of MAX6708TKA+T work in practice?

MAX6708TKA+T provides two independent push-pull RESET outputs on pins 7 (active-low) and 8 (active-high). Both share the same internal reset generator - they assert and deassert simultaneously. Pin 7 goes low during reset and high otherwise; pin 8 goes high during reset and low otherwise. This eliminates need for external inverters when interfacing with mixed-logic families (e.g., driving both 3.3V CMOS and legacy 5V TTL peripherals from one IC).

What is the minimum supply voltage at which MAX6708TKA+T guarantees valid reset operation?

MAX6708TKA+T guarantees valid reset assertion and deassertion down to VCC = 1.0V. Below 1.0V, the RESET outputs become high-impedance (open-circuit), but the device continues monitoring and will reassert reset as soon as VCC rises above 1.0V and crosses the 3.08V threshold. This is confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables, and enables robust operation during severe brownout conditions.