Analog Devices Inc./Maxim Integrated DS1834A

Overview

DS1834A from Maxim Integrated (formerly Dallas Semiconductor) is a dual-voltage power-on reset supervisor IC monitoring both 5V and 3.3V supplies with independent tolerance selection, pushbutton reset input, NMOS open-drain outputs requiring external pull-ups, and guaranteed 350 ms reset pulse width. It serves as the primary system-level reset controller in embedded controllers and industrial microprocessor systems where dual-rail stability is critical.

For engineers reviewing the DS1834A datasheet, DS1834A pinout, DS1834A application, or DS1834A equivalent, key selection considerations include its NMOS output structure (vs. push-pull in DS1834/DS1834D), 5V/3.3V trip point programmability via TOL pins, PBRST debounced manual reset timing, and compatibility with 1.2–5.5 V supply ranges across both inputs.

Technical Context

The DS1834A implements two independent voltage-monitoring channels using precision temperature-compensated references and comparators - one for 5VIN (trip points 4.50–4.75 V at 5% tol, or 4.25–4.49 V at 10% tol) and one for 3.3VIN (2.80–2.97 V at 10% tol, or 2.47–2.64 V at 20% tol). Tolerance is selected per rail by connecting each TOL pin to GND or its respective supply.

It features an internally debounced PBRST input with 2 ms minimum low-time detection and asserts both RST outputs active-low for 200–500 ms after release. Unlike DS1834/DS1834D, DS1834A uses NMOS open-drain outputs requiring external pull-up resistors (typically 10 kΩ) and draws operating current from the higher of the two supply inputs (5VIN or 3.3VIN).

Key Specifications

Pinout & Package

DS1834A is available in 8-pin DIP, 8-pin SOIC (150-mil), and 8-pin µ-SOP (118-mil) packages. All variants share identical pin mapping and function assignment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1834 and MAX6816, DS1834A uniquely supports open-drain wired-AND reset buses and flexible per-rail tolerance selection - making it optimal for systems requiring coordinated reset across heterogeneous voltage domains with shared reset signaling.

Availability

DS1834A is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, telecom line cards, and automotive infotainment head units requiring stable component supply across extended temperature and dual-rail voltage environments.

Supply support for DS1834A 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 (acquired by Analog Devices in 2021) designs precision analog and mixed-signal ICs for industrial, communications, and computing applications.

The DS1834A belongs to Maxim's EconoReset™ family of power-supply supervisors, engineered specifically for cost-effective, dual-voltage reset generation in resource-constrained embedded systems with strict reliability requirements.

FAQ

What is the key functional difference between DS1834A and DS1834?

The DS1834A uses NMOS open-drain outputs requiring external pull-up resistors (typically 10 kΩ), whereas DS1834 features push-pull CMOS outputs that drive high/low actively. This makes DS1834A suitable for wired-AND reset buses, while DS1834 simplifies direct connection to standard CMOS inputs. Both share identical pinout, tolerance programming, and reset timing behavior.

How do I configure the DS1834A for 5% tolerance on the 5V rail?

To set 5% tolerance on the 5V rail, connect the 5V TOL pin to GND. This configures the 5VIN trip point to 4.50–4.75 V (typical 4.63 V). The DS1834A datasheet confirms this setting applies specifically to the DS1834A variant and is validated across -40°C to +85°C operation.

Does DS1834A support operation with only one supply active?

Yes - the DS1834A maintains valid reset outputs as long as at least one input (5VIN or 3.3VIN) remains above 1.2 V. Its internal circuitry draws operating current from the higher of the two supplies, enabling graceful degradation during partial power loss - a confirmed behavior documented in the DS1834A absolute maximum and operating conditions tables.

What is the minimum pulse width for reliable PBRST activation on DS1834A?

The DS1834A requires the PBRST pin to be held low for at least 2 ms to guarantee recognition and initiation of the 350 ms reset pulse. This timing is specified in the AC Electrical Characteristics table and verified across temperature and voltage ranges - shorter pulses may be ignored due to internal debounce logic.

Why does DS1834A require external pull-up resistors while DS1834 does not?

DS1834A implements NMOS open-drain outputs to enable wired-AND configurations and mixed-voltage interfacing, necessitating external pull-ups. DS1834 uses push-pull CMOS outputs that actively drive both logic states. This architectural distinction is explicitly defined in the DS1834A product marking and functional description sections of the official datasheet.