Analog Devices Inc./Maxim Integrated MAX6708YKA

Overview

MAX6708YKA from Maxim Integrated is a low-voltage microprocessor supervisory circuit in an 8-pin SOT23 package, providing dual active-low/active-high push-pull reset outputs, a 0.62V power-fail input comparator with independent PFO output, and manual reset input - but no watchdog timer. It monitors +2.19V supply (Y-suffix threshold), guarantees valid reset down to VCC = 1V, and delivers 140ms reset timeout for reliable power-up/brownout recovery in embedded controllers and industrial systems.

For engineers reviewing the MAX6708YKA datasheet, MAX6708YKA pinout, MAX6708YKA application, or MAX6708YKA equivalent, this device serves as a precision single-supply supervisor with complementary reset outputs and power-fail warning capability - critical for deterministic µP initialization, fail-safe shutdown sequencing, and multivoltage system monitoring where watchdog functionality is not required.

Technical Context

The MAX6708YKA implements a dual-stage reset generator with independent timing control: VCC falling below 2.19V triggers a guaranteed low-going RESET pulse, while the complementary RESET output goes high simultaneously. Its internal 0.62V reference enables precise external voltage monitoring via PFI, with PFO asserting low when input drops below threshold - supporting early power-fail detection without external components.

Unlike watchdog-equipped variants (e.g., MAX6704), MAX6708YKA omits the WDI/WDO circuitry entirely, simplifying design for applications requiring only reset supervision and power-fail signaling. Its dual push-pull reset outputs eliminate need for external pull-ups, and MR input includes internal 50kΩ pullup for direct pushbutton interfacing.

Key Specifications

Pinout & Package

MAX6708YKA uses an 8-pin SOT23-8 package (JEDEC MO-178 BA), 3.00mm × 1.75mm body, 0.65mm pitch, with coplanarity ≤ 0.1mm. Pin 1 marked by dot; lead finish available in SnPb or lead-free (replace -T with +T).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6704YKA, MAX6708YKA removes watchdog circuitry to reduce component count and eliminate potential false-trigger sources, while retaining identical reset timing, PFI accuracy, and dual-output drive strength - making it ideal for deterministic supervision-only use cases.

Availability

MAX6708YKA is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, white goods main control boards, and networking edge router management units requiring stable component supply, extended temperature operation (-40°C to +125°C), and long-term lifecycle continuity.

Supply support for MAX6708YKA 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, emphasizing reliability, integration, and performance under extreme conditions.

The MAX6701–MAX6708 family was engineered specifically for microprocessor power supervision in space- and power-constrained systems, delivering precision reset generation, power-fail warning, and manual reset capability in miniature SOT23 packages - with MAX6708YKA optimized for Y-threshold (2.19V) applications without watchdog overhead.

FAQ

What is the reset threshold voltage for MAX6708YKA?

The MAX6708YKA has a factory-trimmed VCC reset threshold of 2.19V (Y-suffix), with tolerance of ±1.5% over the full -40°C to +125°C operating range. This value is specified in the Electrical Characteristics table and applies to the primary VCC monitor input. The device guarantees valid reset assertion down to VCC = 1V, ensuring robust behavior during deep brownout conditions.

Does MAX6708YKA include a watchdog timer function?

No, MAX6708YKA does not include a watchdog timer. As explicitly stated in the General Description and Selector Guide, MAX6708 is "the same as the MAX6704 but without the watchdog timer function." It provides reset supervision, manual reset input, and power-fail monitoring (PFI/PFO), but lacks WDI and WDO pins - confirmed by pin configuration diagrams showing pin 6 as N.C. and absence of watchdog timing parameters in its datasheet section.

What are the key differences between MAX6708YKA and MAX6704YKA?

MAX6708YKA and MAX6704YKA share identical package, temperature range, reset thresholds, PFI/PFO functionality, and dual complementary reset outputs. The sole functional difference is that MAX6704YKA includes a 1.6s watchdog timer with reset-based timeout assertion, while MAX6708YKA omits all watchdog circuitry - resulting in pin 6 being N.C. and no WDI/WDO timing specifications. Both parts guarantee reset validity to VCC = 1V.

How does the power-fail comparator work in MAX6708YKA?

The MAX6708YKA's power-fail comparator uses an internal 0.62V reference connected to the inverting input; the non-inverting input is brought out to the PFI pin. When an external voltage divider applies a voltage to PFI that falls below 0.62V, the comparator asserts the PFO output low. This enables early warning of supply collapse - for example, configuring PFI to monitor a 5V rail so PFO triggers ~100ms before regulator dropout, allowing µP to execute safe shutdown routines.

What is the reset timeout period for MAX6708YKA and how is it implemented?

The MAX6708YKA features a factory-trimmed reset timeout period of 140ms (typical), with a guaranteed range of 120ms to 300ms over -40°C to +125°C. This delay begins when VCC rises above the 2.19V threshold (or when MR is released) and holds the RESET outputs in their asserted state - ensuring the microprocessor remains held in reset long enough for clocks, PLLs, and peripherals to stabilize before execution resumes.