Analog Devices Inc./Maxim Integrated DS1706TEUA+

Overview

DS1706TEUA+ from Maxim Integrated is a 3.3V ±5% precision microprocessor supervisory circuit with watchdog timer, non-maskable interrupt (NMI), and pushbutton reset control in an 8-pin µSOP package. It monitors VCC, detects software hangs via strobe input, and provides early power-fail warning via external voltage sense (IN pin). Used in industrial embedded systems requiring reliable power-up sequencing and fault recovery.

For engineers reviewing the DS1706TEUA+ datasheet, DS1706TEUA+ pinout, DS1706TEUA+ application, or DS1706TEUA+ equivalent, key selection criteria include its 3.3V ±5% reset threshold, 130 ms minimum reset pulse width, 1 s watchdog timeout, NMI generation at 1.25 V trip point on IN, and compatibility with µSOP-8 PCB footprints.

Technical Context

The DS1706TEUA+ integrates three independent monitoring functions: (1) VCC supply monitoring with 3.3V ±5% trip point (VCCTP = 3.00–3.15 V), (2) external voltage sensing via high-impedance IN pin referenced to 1.25 V internal bandgap, and (3) watchdog timer triggered by ST input transitions with 1.0–2.2 s timeout. All functions operate across –40°C to +85°C.

Its RST output is active-low with guaranteed 130–285 ms assertion time; NMI pulses low for ≥200 µs upon IN voltage decay; WDS asserts low for ≥130 ms after watchdog timeout. Internal pull-ups (40 kΩ on PBRST, 180 kΩ on ST) enable direct switch or microcontroller signal interfacing without external components.

Key Specifications

Pinout & Package

DS1706TEUA+ is housed in an 8-pin µSOP (118-mil) package, RoHS-compliant and lead-free, with 0.5 mm pitch and exposed pad for thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706TESA+ and TPS3808G33DBVR, DS1706TEUA+ uniquely combines 3.3V ±5% reset, NMI, and IN-based external monitoring in one µSOP-8 device - enabling both fail-safe reset and pre-failure diagnostics without additional ICs.

Availability

DS1706TEUA+ is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, telecom infrastructure, and smart metering applications requiring stable component supply and long-term lifecycle support.

Supply support for DS1706TEUA+ 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 industrial, automotive, communications, and computing markets.

The DS1706TEUA+ belongs to the MicroMonitor™ family - engineered specifically for robust microprocessor supervision in mission-critical embedded systems where power integrity and software reliability are non-negotiable.

FAQ

What is the exact reset voltage threshold for DS1706TEUA+?

The DS1706TEUA+ has a guaranteed VCC reset threshold of 3.00 V (min), 3.08 V (typ), and 3.15 V (max) - corresponding to 3.3V ±5%. This specification is validated across –40°C to +85°C and ensures consistent brownout detection in 3.3V systems without external calibration. The DS1706TEUA+ uses an internal temperature-compensated bandgap reference to maintain this accuracy over temperature and supply variation.

Does DS1706TEUA+ support external voltage monitoring beyond VCC?

Yes, DS1706TEUA+ supports external voltage monitoring via its IN pin, which has a precise 1.20–1.30 V trip point referenced to an internal bandgap. By connecting a resistor divider from the target supply to IN and GND, users can monitor any DC voltage - including higher rails or isolated supplies - with sub-100 µV hysteresis. This feature is confirmed in the DS1706TEUA+ datasheet Figure 5 and electrical specifications table.

What is the function of the NMI pin on DS1706TEUA+?

The NMI pin on DS1706TEUA+ is an active-low, open-drain non-maskable interrupt output that pulses low for ≥200 µs when the IN pin voltage falls below its 1.25 V trip point. It provides early warning of impending power failure before RST activates, allowing the microprocessor to execute critical save routines. Its 100 µV hysteresis and 5 µs noise immunity ensure reliable operation in electrically noisy environments.

How does the watchdog timer on DS1706TEUA+ operate?

The DS1706TEUA+ watchdog timer starts counting after RST goes inactive and times out after 1.0–2.2 s if no high-to-low transition occurs on the ST pin. Upon timeout, WDS asserts low for ≥130 ms. ST is internally pulled up to VCC (180 kΩ), so a microcontroller GPIO or address/data line can serve as the strobe source. This mechanism detects software hangs independently of VCC status.

Is DS1706TEUA+ pin-compatible with other MicroMonitor devices?

Yes, DS1706TEUA+ is pin-compatible with the MAX705/MAX706 series in 8-pin DIP, SOIC, and µSOP packages, as explicitly stated in the datasheet Features section. This includes identical pin assignments for VCC, GND, RST, PBRST, ST, NMI, IN, and WDS. However, functional differences exist - e.g., MAX706 lacks the IN pin and NMI output - so schematic review is required before substitution.