Analog Devices Inc./Maxim Integrated DS1834AS+T&R

Overview

DS1834AS+T&R from Maxim Integrated (now Analog Devices) is a dual-voltage power-on reset supervisor IC monitoring both 5V and 3.3V supplies, featuring pushbutton reset input, 350 ms reset pulse width, ±5% / ±10% selectable voltage tolerance, and CMOS push-pull outputs. It serves as a system-level power integrity guardian in embedded controllers requiring dual-rail reset coordination.

For engineers reviewing the DS1834AS+T&R datasheet, DS1834AS+T&R pinout, DS1834AS+T&R application, or DS1834AS+T&R equivalent, key selection criteria include dual-supply trip point accuracy, PBRST debounced timing, reset hold duration, output drive capability, and package compatibility with SOIC-8 footprint constraints.

Technical Context

The DS1834AS+T&R implements independent precision voltage comparators with temperature-compensated references for 5VIN (trip range 4.50–4.75 V at 5% tol, 4.25–4.49 V at 10% tol) and 3.3VIN (2.80–2.97 V at 10% tol, 2.47–2.64 V at 20% tol), each driving dedicated active-low reset outputs with 350 ms minimum assertion time after recovery.

Internal power routing selects the higher of 5VIN or 3.3VIN to supply core logic; outputs are sourced/sunk only from their respective supply rails. The PBRST pin features internal 40 kΩ pull-up and ≥2 ms debounce threshold, forcing both resets active for ~350 ms after release.

Key Specifications

Pinout & Package

DS1834AS+T&R is packaged in an 8-pin SOIC (150-mil width), pin-compatible with industry-standard SOIC-8 footprints and reflow-solderable per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply reset supervision applications.

Compared with MAX6326US33D3+ and TPS3808G33DBVR, DS1834AS+T&R uniquely integrates dual-voltage monitoring, pushbutton override, and matched 350 ms reset timing in one SOIC-8 package-eliminating inter-supervisor timing skew and reducing PCB area by >30%.

Availability

DS1834AS+T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, telecom edge routers, and automotive infotainment head units requiring stable component supply and long-term lifecycle support.

Supply support for DS1834AS+T&R 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

Analog Devices (via acquisition of Maxim Integrated) designs high-performance analog, mixed-signal, and power management ICs for precision sensing, power integrity, and reliable system supervision.

The DS1834AS+T&R belongs to Maxim's EconoReset™ family-engineered specifically for cost-sensitive, space-constrained embedded systems needing dual-rail power monitoring without external passive components.

FAQ

What is the function of the 5V TOL and 3.3V TOL pins on the DS1834AS+T&R?

The 5V TOL and 3.3V TOL pins on the DS1834AS+T&R configure voltage detection thresholds: tying 5V TOL to GND sets 5V trip at 4.50–4.75 V (5% tolerance), while connecting it to 5VIN sets 4.25–4.49 V (10% tolerance). Similarly, 3.3V TOL selects 2.80–2.97 V (10%) or 2.47–2.64 V (20%). This eliminates external resistor networks and enables field-programmable trip points without redesigning the DS1834AS+T&R layout.

Does the DS1834AS+T&R require external pull-up resistors on its reset outputs?

No-the DS1834AS+T&R uses CMOS push-pull outputs and does not require external pull-ups. Its 5V RST and 3.3V RST pins actively drive high or low, delivering VOH ≥ VIN − 0.1 V and sinking up to 10 mA. This differs from the DS1834A variant (open-drain), confirming that DS1834AS+T&R simplifies design by removing two external resistors versus DS1834A implementations.

How long does the DS1834AS+T&R hold reset after power returns to tolerance?

The DS1834AS+T&R holds both 5V RST and 3.3V RST active for 200–500 ms after the monitored supply returns to tolerance, with typical duration of 350 ms. This timing is internally generated and independent of external capacitors-ensuring consistent reset hold across temperature (-40°C to +85°C) and voltage variations, critical for reliable DS1834AS+T&R deployment in industrial environments.

Can the DS1834AS+T&R operate if only one supply rail is present?

Yes-the DS1834AS+T&R operates with either 5VIN or 3.3VIN present (≥1.2 V), drawing internal power from the higher rail. If only 3.3VIN is applied, the 5V RST remains valid but inactive unless 5VIN is restored; conversely, with only 5VIN, the 3.3V RST stays inactive. This rail-flexible behavior makes DS1834AS+T&R suitable for partial-power scenarios like hot-swap modules or modular backplanes.

What is the maximum allowable slew rate for the supply inputs on the DS1834AS+T&R?

The DS1834AS+T&R specifies a maximum VCC slew rate of 300 µs between VINTP(MIN) and VINTP(MAX) to ensure accurate trip point detection without false triggering. For example, transitioning from 4.25 V to 4.75 V must occur over ≥300 µs. Faster edges may cause metastable comparator behavior-so designers should verify input ramp rates in DS1834AS+T&R applications involving fast-switching DC/DC converters or unfiltered lab supplies.