Analog Devices Inc./Maxim Integrated DS1708RESA+

Overview

DS1708RESA+ from Maxim Integrated is a 3.3V microprocessor supervisory circuit with ±20% VCC reset threshold, active-low and active-high reset outputs (RST and RST), non-maskable interrupt (NMI), and pushbutton reset debouncing. It monitors power supply integrity, provides early power-fail warning via IN-sense input, and guarantees ≥130ms reset pulse width. Used in industrial embedded systems requiring reliable power-up/power-down sequencing and brownout protection.

For engineers reviewing the DS1708RESA+ datasheet, DS1708RESA+ pinout, DS1708RESA+ application, or DS1708RESA+ equivalent, key selection criteria include its 3.3V ±20% trip point (VCCTP = 2.55V to 2.70V), dual-reset output polarity, NMI generation at 1.25V IN threshold, 130ms minimum reset timeout, and compatibility with 8-pin SOIC (150-mil) footprint.

Technical Context

The DS1708RESA+ implements a precision bandgap-referenced comparator for VCC monitoring and an independent high-impedance IN input for external voltage sensing. Its internal hysteresis (100µV on NMI path) and 5µs noise immunity reject transients, while the PBRST input includes 40kΩ internal pull-up and hardware debouncing.

It delivers two synchronized reset signals-active-low RST and active-high RST-with identical timing (tRST = 130–285ms), plus a 200µs NMI pulse triggered when the IN voltage falls below 1.25V. The device operates across 1.2V–5.5V supply range but is configured specifically for 3.3V ±20% monitoring per ordering code RESA.

Key Specifications

Pinout & Package

DS1708RESA+ is supplied in an 8-pin SOIC package (150-mil width, JEDEC MS-012), with gull-wing leads and standard thermal profile compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX708ESA+, DS1708RESA+ offers 3.3V-specific monitoring and IN-based early warning; compared with TPS3808G33DBVR, it provides dual-reset polarity, NMI, and hardware-debounced PBRST-critical for systems requiring deterministic shutdown sequencing and field-service reset capability.

Availability

DS1708RESA+ is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, telecom infrastructure, and smart metering applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

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, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The DS1708RESA+ belongs to the MicroMonitor™ family of supervisory circuits engineered for reliable power-up sequencing, brownout detection, and fail-safe shutdown in mission-critical embedded systems.

FAQ

What is the exact VCC trip point range for DS1708RESA+?

The DS1708RESA+ has a guaranteed VCC trip point (VCCTP) of 2.55V (min), 2.63V (typ), and 2.70V (max), corresponding to ±20% tolerance around a nominal 3.3V supply. This range is specified over the full -40°C to +85°C operating temperature and is temperature-compensated using an internal bandgap reference. These values are measured per the DS1707/DS1708 datasheet Rev. 0, page 7, DC Electrical Characteristics table.

Does DS1708RESA+ support both active-low and active-high reset outputs simultaneously?

Yes, DS1708RESA+ provides two independent reset outputs: RST (active-low, open-drain) and RST (active-high, push-pull). Both assert synchronously during power-up, power-down, or PBRST activation, with identical timing (tRST = 130–285ms). This dual-output architecture eliminates the need for external inverters when interfacing with MCUs or FPGAs requiring either polarity reset signal.

Can DS1708RESA+ monitor a voltage higher than its VCC supply?

Yes, DS1708RESA+ can monitor voltages above VCC using the IN pin with an external resistor divider. The IN input is high-impedance (leakage ±1.0µA) and referenced to an internal 1.25V bandgap. As shown in Figure 5 of the datasheet, a properly scaled divider allows monitoring of rails such as 5V or 12V while keeping the IN voltage ≤ VCC. The maximum allowable monitored voltage (VMAX) is derived from VCC and the divider ratio.

Is DS1708RESA+ pin-compatible with the MAX708 series?

Yes, DS1708RESA+ is explicitly documented as pin-compatible with the MAX707/MAX708 in 8-pin SOIC packages. Pin assignments-including PBRST, VCC, GND, IN, RST, RST, NC, and NMI-are identical. This allows direct substitution in existing layouts designed for MAX708ESA+, provided the 3.3V ±20% monitoring profile meets the system's requirements.

What is the minimum reset pulse width guaranteed by DS1708RESA+?

DS1708RESA+ guarantees a minimum reset pulse width of 130ms for both RST and RST outputs during power-up, power-down, or PBRST activation. This value is specified across temperature and supply voltage (tRST min = 130ms, typ = 205ms, max = 285ms per datasheet page 8). The timing starts when VCC crosses VCCTP on power-up or when PBRST is released from low.