Analog Devices Inc./Maxim Integrated DS1708RESA

Overview

DS1708RESA from Maxim Integrated is a 3.3V ±20% precision voltage supervisor IC that monitors VCC, senses external supply voltage via IN pin, and debounces pushbutton reset input (PBRST) to generate active-high and active-low reset outputs (RST and RST). It delivers 130 ms minimum reset pulse width, non-maskable interrupt (NMI) for early power-fail warning, and operates across -40°C to +85°C in industrial systems.

For engineers reviewing the DS1708RESA datasheet, DS1708RESA pinout, DS1708RESA application, or DS1708RESA equivalent, key selection criteria include its 3.3V-20% VCC trip point (2.55V–2.70V), dual-reset output polarity, NMI timing (200 µs pulse, 5 µs noise immunity), pushbutton debounce logic, and compatibility with 8-pin SOIC layout constraints.

Technical Context

The DS1708RESA implements a dual-threshold monitoring architecture: one comparator tracks VCC directly against an internal bandgap reference (VCCTP = 2.55V–2.70V), while a second high-impedance comparator monitors an external supply via the IN pin (VTP = 1.20V–1.30V). Both comparators drive independent timing circuits - one for RST/RST assertion (130 ms min), another for NMI generation (200 µs min, 5 µs detection delay).

Its PBRST input is internally pulled up to VCC (40 kΩ typical) and triggers synchronized reset pulses only upon release of a low-level button press. The device requires no external components for basic operation and supports automatic reset restart after brownout recovery, with hysteresis built into both VCC and IN sensing paths.

Key Specifications

Pinout & Package

DS1708RESA is housed in an 8-pin SOIC (150-mil) package with exposed pad not present. Pin functions are electrically identical across DIP, SOIC, and µSOP variants per Maxim's mechanical drawings.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with MAX708ESA and TPS3808G33DBVR, DS1708RESA uniquely combines 3.3V-20% supervision, external voltage sensing (IN), non-maskable interrupt (NMI), and debounced pushbutton reset (PBRST) in a standard 8-pin SOIC - enabling robust, multi-layer power integrity monitoring without additional discrete components.

Availability

DS1708RESA is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom line cards, medical diagnostic modules, and automotive infotainment head units requiring stable component supply and long-term lifecycle support.

Supply support for DS1708RESA 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 power management, sensing, and interface applications in industrial, automotive, and communications systems.

The DS1708RESA belongs to the MicroMonitor™ family - engineered specifically for multi-rail voltage supervision in microprocessor-based systems requiring coordinated reset sequencing, early fault detection, and manual override capability.

FAQ

What is the exact VCC trip point range for DS1708RESA?

The DS1708RESA has a specified VCC trip point of 2.55V (minimum), 2.63V (typical), and 2.70V (maximum), corresponding to 3.3V ±20% tolerance. This range is validated across -40°C to +85°C and ensures reliable reset assertion before most 3.3V microprocessors enter undefined operating states. The DS1708RESA datasheet confirms this specification under DC Electrical Characteristics.

Does DS1708RESA support external voltage monitoring, and how is it implemented?

Yes, DS1708RESA supports external voltage monitoring via its IN pin, which compares an externally divided voltage against an internal 1.25V bandgap reference. A resistor divider (e.g., R1 = 26 kΩ, R2 = 10 kΩ) scales higher supply voltages (e.g., 12V) down to the 1.25V threshold. The DS1708RESA's high-impedance IN input draws less than 1 µA, minimizing loading on the monitored rail.

How does the NMI output of DS1708RESA differ from the RST outputs in timing and function?

The DS1708RESA NMI output pulses low for ≥200 µs when the IN pin voltage drops below 1.25V, providing early warning of impending power failure. In contrast, RST and RST assert after VCC falls below 2.55V and remain active for ≥130 ms. This 5–10 ms timing gap gives firmware time to save state before hard reset - a capability not replicated by the RST outputs alone.

Can DS1708RESA replace MAX707/MAX708 in existing designs without layout changes?

Yes, DS1708RESA is pin-compatible with MAX707/MAX708 in 8-pin SOIC packages, sharing identical pin assignments (PBRST, VCC, GND, IN, RST, RST, NC, NMI). No PCB modifications are required for substitution, though firmware should verify NMI handling since MAX707/MAX708 lack the IN pin and NMI functionality present in DS1708RESA.

What is the guaranteed reset pulse width generated by DS1708RESA during power-up or pushbutton event?

The DS1708RESA guarantees a minimum reset pulse width of 130 ms for both power-up recovery and pushbutton-initiated reset events. This duration is measured from VCC crossing VCCTP (or PBRST release) until RST and RST return to inactive states. The DS1708RESA datasheet specifies tRST = 130–285 ms under all operating conditions, ensuring sufficient time for microprocessor clock stabilization and memory initialization.