Analog Devices Inc./Maxim Integrated MAX708TCUA

Overview

MAX708TCUA from Maxim Integrated is a +3V microprocessor supervisory circuit with active-high and active-low reset outputs, 3.08V reset threshold, 200ms reset pulse width, 100µA quiescent current, and 1.25V power-fail comparator input-designed for reliable power-up/power-down monitoring in battery-powered portable instruments and embedded controllers.

For engineers reviewing the MAX708TCUA datasheet, MAX708TCUA pinout, MAX708TCUA application, or MAX708TCUA equivalent, this device delivers dual-reset signaling, brownout immunity down to VCC = 1V, precision voltage supervision for +3.3V systems, and integrated manual reset debouncing-key for industrial control, medical handhelds, and low-power IoT edge nodes.

Technical Context

The MAX708TCUA integrates a dual-output reset generator with independent active-high (RESET) and active-low (RESET) signals, both asserted when VCC falls below 3.08V or MR is pulled low, and deasserted after a guaranteed 200ms delay upon recovery. Its internal 1.25V reference enables flexible power-fail or low-battery detection via external resistive divider on PFI.

Unlike MAX706 variants, MAX708TCUA omits the watchdog timer but adds simultaneous complementary reset outputs-eliminating need for external inverters in systems requiring both logic polarities. It operates across 1.2V to 5.5V supply range and guarantees RESET assertion down to VCC = 1V, ensuring deterministic behavior during deep brownout.

Key Specifications

Pinout & Package

MAX708TCUA is housed in an 8-pin µMAX® package (U8-1), measuring 3mm × 3mm × 0.8mm, with exposed pad for thermal enhancement and lead-free RoHS compliance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706TCUA and TPS3808G30DBVR, MAX708TCUA uniquely provides simultaneous active-high and active-low reset outputs plus integrated 1.25V power-fail comparator-reducing BOM count by two components in systems requiring both reset polarities and early power-loss warning.

Availability

MAX708TCUA is available at Aetrix Electronics and suitable for portable medical devices, industrial PLC I/O modules, smart energy meters, and automotive body control units requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for MAX708TCUA 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, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX708 family delivers cost-effective, highly integrated µP supervisory functions-including dual-reset signaling and power-fail detection-for resource-constrained embedded systems where reliability and small footprint are critical.

FAQ

What is the reset threshold voltage for MAX708TCUA?

The MAX708TCUA has a nominal reset threshold of 3.08V (VCC falling), with ±75mV tolerance over temperature and supply range. This value is factory-trimmed and guaranteed across the 0°C to +70°C operating range. The threshold applies to both RESET and RESET outputs, which assert simultaneously when VCC drops below this level. The device also includes 20mV hysteresis to prevent oscillation near the trip point.

Does MAX708TCUA include a watchdog timer function?

No, MAX708TCUA does not include a watchdog timer. Unlike the MAX706 series, the MAX708 family replaces the watchdog input (WDI) and watchdog output (WDO) pins with a second reset output (RESET). The MAX708TCUA provides only voltage supervision, manual reset, and power-fail detection-making it ideal for applications where watchdog functionality is implemented elsewhere or unnecessary.

How do I connect the PFI pin for power-fail detection on MAX708TCUA?

To use PFI for power-fail detection, connect it to a resistive voltage divider between the unregulated supply (e.g., raw battery or DC input) and ground. Select R1 and R2 so that PFI voltage falls below 1.25V just before the regulated +3.3V rail collapses. For example, with a 12V input and 1.25V threshold, use R1 = 130kΩ and R2 = 1MΩ. PFO will go low when the condition is met, allowing µP interrupt or controlled shutdown.

Can MAX708TCUA operate with a 1.8V supply?

Yes, MAX708TCUA is specified to operate down to VCC = 1.2V. At 1.8V, the 3.08V reset threshold is not active-instead, the device guarantees RESET assertion as long as VCC remains ≥1V. However, output drive strength and timing parameters shift: RESET pulse width remains 200ms, but VOL/VOL specs degrade slightly. Full functionality-including PFI comparator accuracy-is ensured only above VCC = 2.7V.

What is the purpose of the N.C. pin on MAX708TCUA?

Pin 6 of MAX708TCUA is marked N.C. (No Connection) and is not internally bonded. It must be left unconnected-neither tied to VCC nor GND-to avoid potential latch-up or parametric deviation. This pin exists due to package compatibility with other members of the MAX706/MAX708 family (e.g., MAX706 variants use this pin for WDO), but serves no function in MAX708TCUA.