Analog Devices Inc./Maxim Integrated DS1706RESA+

Overview

DS1706RESA+ from Maxim Integrated is a 3.3V microprocessor supervisory circuit with active-low reset output, watchdog timer, non-maskable interrupt, and pushbutton reset control. It monitors VCC for 20% tolerance (trip point 2.85–3.00V), provides 130ms minimum reset pulse width, and operates across –40°C to +85°C. Used in embedded systems requiring reliable power-up sequencing and fault recovery.

For engineers reviewing the DS1706RESA+ datasheet, DS1706RESA+ pinout, DS1706RESA+ application, or DS1706RESA+ equivalent, key selection criteria include VCC trip accuracy, watchdog timeout (1.0–2.2s), NMI response time (5–8μs), and compatibility with 3.3V microcontroller power rails and reset logic.

Technical Context

The DS1706RESA+ integrates three independent monitoring functions: precision voltage detection using an internal 1.25V bandgap reference and comparator for VCC and external supply (IN pin), a 1-second watchdog timer triggered by ST input transitions, and debounced pushbutton reset with guaranteed 130ms active-low RST pulse. All functions operate within a single 8-pin SOIC package.

Its power monitor detects VCC decay below 2.85–3.00V (DS1706S variant) and asserts RST within 5–8μs; the NMI output pulses low for ≥200μs when IN falls below 1.20–1.30V, providing early warning before reset. The watchdog resets on each ST high-to-low edge and forces WDS low for ≥130ms if timing out.

Key Specifications

Pinout & Package

DS1706RESA+ is housed in an 8-pin SOIC (150-mil) package, RoHS-compliant and lead-free, with standard JEDEC MS-012AC footprint and thermal characteristics suitable for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706TESA+ and TPS3808G33DBVR, DS1706RESA+ uniquely combines VCC supervision, external supply monitoring (IN), non-maskable interrupt, and watchdog timer in a single 8-pin SOIC-enabling comprehensive system-level fault detection and recovery unattainable with simpler supervisors.

Availability

DS1706RESA+ is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, smart metering, and automotive telematics requiring stable component supply and long-term lifecycle assurance.

Supply support for DS1706RESA+ 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, medical, communications, and computing applications.

The DS1706RESA+ belongs to the MicroMonitor™ family-engineered specifically for robust microprocessor supervision in mission-critical embedded systems demanding simultaneous voltage, software, and user-event monitoring.

FAQ

What is the exact VCC trip voltage range for DS1706RESA+?

The DS1706RESA+ has a guaranteed VCC trip point of 2.85V (min), 2.93V (typ), and 3.00V (max), corresponding to a 20% tolerance around 3.3V. This range is specified in the DC Electrical Characteristics table under "VCC Trip Point DS1706S" and applies directly to DS1706RESA+. The device asserts RST when VCC falls below this threshold and holds it active for ≥130ms after recovery.

Does DS1706RESA+ provide both active-high and active-low reset outputs?

No, DS1706RESA+ provides only an active-low reset output (RST). The datasheet explicitly lists DS1706RESA+ in the Ordering Information table under "3.3V-20% MONITOR, /RST, /WDS", where the leading slash denotes active-low polarity. Unlike DS1706LESA+ (which offers RST) or DS1706PESA+ (which offers RST), DS1706RESA+ does not include an active-high reset output.

How does the watchdog timer in DS1706RESA+ interact with the reset function?

The DS1706RESA+ watchdog timer starts timing only after RST becomes inactive (i.e., after power-up stabilization). It monitors the ST input and times out after 1.0–2.2s if no high-to-low transition occurs. On timeout, WDS goes active-low for ≥130ms-but this does not assert RST. RST is only triggered by VCC drop, PBRST, or power-up; WDS serves solely as a status flag for external logic or microcontroller polling.

Can DS1706RESA+ monitor a 12V supply while powered from 3.3V?

Yes, DS1706RESA+ can monitor higher-voltage supplies using its IN pin. The IN input accepts voltages up to VCC (3.3V) directly, but with an external resistor divider (e.g., R1=26kΩ, R2=10kΩ), it senses 12V at the divider output as 1.25V-the internal trip reference. The datasheet provides the equation VSENSE = [R2/(R1+R2)] × 1.25V and confirms this configuration in Figure 5, enabling safe upstream supply monitoring without level-shifting ICs.

Is DS1706RESA+ pin-compatible with the MAX705/MAX706 series?

Yes, DS1706RESA+ is explicitly stated as pin-compatible with MAX705/MAX706 in 8-pin DIP, SOIC, and μ-SOP packages. Its pin assignment matches identically: Pin 1=PBRST, Pin 2=VCC, Pin 3=GND, Pin 4=IN, Pin 5=WDS, Pin 6=RST, Pin 7=ST, Pin 8=NMI. This allows direct replacement in existing layouts designed for those Maxim legacy supervisors, provided the 20% trip point and feature set meet system requirements.