Analog Devices Inc./Maxim Integrated DS1834AS

Overview

DS1834AS from Maxim Integrated (now Analog Devices) is a dual-voltage supervisor IC that independently monitors 5V and 3.3V power supplies while supporting manual reset via debounced pushbutton input. It provides active-low push-pull reset outputs with 350 ms reset timeout, ±5% and ±10% selectable voltage tolerances, and operates from -40°C to +85°C in 8-pin µ-SOP package - used in embedded systems requiring reliable dual-rail power sequencing and fault recovery.

For engineers reviewing the DS1834AS datasheet, DS1834AS pinout, DS1834AS application, or DS1834AS equivalent, key selection criteria include dual-supply trip point configurability (via TOL pins), guaranteed 350 ms reset assertion after power recovery, push-pull output drive capability without external pull-ups, and compatibility with mixed-voltage microcontroller reset inputs.

Technical Context

The DS1834AS integrates two independent voltage comparators with precision temperature-compensated references, each feeding a dedicated reset generator with fixed 350 ms timeout. Its internal power selector draws operating current from the higher of 5VIN or 3.3VIN, enabling operation during asymmetric supply ramp-up/down.

Reset assertion is triggered when either supply falls outside its configured tolerance band (±5%/±10% for 5V; ±10%/±20% for 3.3V), and both resets are forced active upon PBRST low pulse ≥2 ms. Output validity is maintained down to 1.2 V on supply inputs, with push-pull structure eliminating need for external pull-up resistors.

Key Specifications

Pinout & Package

DS1834AS is housed in an 8-pin µ-SOP (118-mil) package with exposed pad for thermal performance and board space efficiency.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6816ESE+ and TPS3808G33DBVR, the DS1834AS delivers integrated dual-supply monitoring with hardware-configurable tolerances and true push-pull outputs - reducing component count, PCB area, and design validation effort in multi-rail embedded systems.

Availability

DS1834AS is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, automotive infotainment, and telecom infrastructure applications requiring stable component supply and long-term lifecycle support.

Supply support for DS1834AS 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 (formerly Maxim Integrated) designs high-performance analog, mixed-signal, and power management ICs for precision sensing, power integrity, and system reliability.

The DS1834AS belongs to the EconoReset™ family of voltage supervisors, engineered specifically for cost-sensitive, space-constrained embedded systems needing robust dual-rail power monitoring without external components.

FAQ

What is the function of the TOL pins on the DS1834AS?

The 5V TOL and 3.3V TOL pins on the DS1834AS configure the voltage detection tolerance bands: grounding selects ±5% (5V) and ±10% (3.3V); tying to respective supply selects ±10% (5V) and ±20% (3.3V). This hardware-based selection eliminates need for configuration registers or external resistors, simplifying design and improving reliability. The DS1834AS uses these settings to determine trip thresholds before asserting reset outputs.

Does the DS1834AS require external pull-up resistors on its reset outputs?

No, the DS1834AS features push-pull output drivers on both 5V RST and 3.3V RST pins, enabling direct interface with CMOS/TTL reset inputs without external pull-up resistors. This differs from open-drain alternatives like the DS1834A variant. The DS1834AS output can source up to 350 µA and sink up to 10 mA, ensuring robust noise immunity and fast edge rates in real-world PCB environments.

How does the DS1834AS handle power sequencing when both 5VIN and 3.3VIN are present?

The DS1834AS automatically draws internal operating current from the higher of the two supply inputs (5VIN or 3.3VIN), ensuring continuous supervision even during asymmetric power-up or brown-out conditions. Both reset outputs remain asserted until their respective supplies stabilize within tolerance, with 350 ms timeout applied independently. This behavior makes the DS1834AS ideal for systems where 5V and 3.3V rails ramp at different rates.

What is the minimum pulse width required on PBRST to trigger a manual reset on the DS1834AS?

The DS1834AS requires a minimum 2 ms low pulse on the PBRST pin to initiate manual reset - a value confirmed in the AC Electrical Characteristics table. The internal debounce circuit filters shorter transients, preventing false triggers from switch bounce or EMI. Once asserted, both 5V RST and 3.3V RST remain active for 350 ms after PBRST returns high, matching the power-fail reset timeout. This timing is fixed and not user-adjustable in the DS1834AS.

Can the DS1834AS operate with supply voltages below 3.3V or 5V?

Yes, the DS1834AS supports supply inputs from 1.2 V to 5.5 V on both 5VIN and 3.3VIN pins, allowing valid operation during brown-out, partial power-down, or low-voltage test modes. Output validity is maintained down to 1.2 V on either input; below that, a 100 kΩ pull-down resistor from RST to GND ensures defined logic state. This extended range enhances system resilience in battery-powered or energy-harvesting applications using the DS1834AS.