Analog Devices Inc./Maxim Integrated DS1834S+T&R

Overview

DS1834S+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 override, 350 ms reset pulse width, ±5% or ±10% selectable voltage tolerance per rail, and CMOS push-pull outputs. It serves as a system-level power integrity guardian in embedded controllers requiring dual-rail stability.

For engineers reviewing the DS1834S+T&R datasheet, DS1834S+T&R pinout, DS1834S+T&R application, or DS1834S+T&R equivalent, key selection criteria include dual-supply trip point configurability, internal debounced PBRST, guaranteed 350 ms reset assertion after VCC recovery, and SOIC-8 package compatibility with industrial temperature range operation.

Technical Context

The DS1834S+T&R implements independent precision voltage comparators with temperature-compensated references for 5VIN and 3.3VIN rails, each configurable via dedicated TOL pins to select either 5%/10% (5V) or 10%/20% (3.3V) tolerance thresholds. Internal logic asserts corresponding RST outputs on out-of-tolerance detection.

It draws operating current from the higher of the two supply inputs (5VIN or 3.3VIN), powers internal circuitry including a 40 kΩ pull-up on PBRST, and delivers active-low CMOS push-pull reset outputs capable of sinking 10 mA while maintaining valid logic states down to 1.2 V input - enabling robust reset signaling during brownout conditions.

Key Specifications

Pinout & Package

DS1834S+T&R is supplied in an 8-pin SOIC (150-mil) package, RoHS-compliant and tape-and-reel packaged per EIA-481 standard.

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, DS1834S+T&R uniquely integrates dual-rail voltage supervision, hardware-selectable tolerances, and debounced pushbutton reset in one SOIC-8 package-making it irreplaceable for systems requiring coordinated reset of mixed-voltage subsystems.

Availability

DS1834S+T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic equipment, telecom line cards, and automotive infotainment head units requiring stable component supply across extended production lifecycles.

Supply support for DS1834S+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 (including former Maxim Integrated) designs high-performance analog, mixed-signal, and power management ICs for precision sensing, power integrity, and reliable system control.

The DS1834S+T&R belongs to Maxim's EconoReset™ family, engineered specifically for cost-sensitive yet robust dual-rail power monitoring in industrial and embedded systems where reliability under voltage transients is critical.

FAQ

What is the function of the 5V TOL and 3.3V TOL pins on the DS1834S+T&R?

The 5V TOL and 3.3V TOL pins on the DS1834S+T&R configure the voltage tolerance window for each monitored rail. When tied to GND, 5VIN trips at 4.50–4.75 V (±5%) and 3.3VIN at 2.80–2.97 V (±10%). When tied to their respective supply inputs, tolerances widen to ±10% (5V) and ±20% (3.3V). This hardware-selectable flexibility allows DS1834S+T&R to adapt to varying power supply specifications without firmware or external components.

Does the DS1834S+T&R require external pull-up resistors on its RST outputs?

No, the DS1834S+T&R does not require external pull-up resistors on its RST outputs because it uses CMOS push-pull drivers - unlike the open-drain DS1834A variant. The DS1834S+T&R can actively drive both high and low states, delivering VOH ≥ VIN – 0.1 V and sinking up to 10 mA. This eliminates external components and simplifies interface with microcontrollers expecting active-drive reset inputs.

How long does the DS1834S+T&R hold reset after a power supply returns to tolerance?

The DS1834S+T&R holds each RST output active for 200–500 ms (typical 350 ms) after its associated supply (5VIN or 3.3VIN) returns to within the selected tolerance band. This guaranteed minimum pulse width ensures reliable processor initialization and memory stabilization. The timing is internally generated and independent of external capacitors or supply slew rate, making DS1834S+T&R highly predictable in noisy or dynamically loaded environments.

Can the DS1834S+T&R operate if only one supply rail is present?

Yes, the DS1834S+T&R remains fully functional with only one supply rail active. It draws internal operating current from whichever input (5VIN or 3.3VIN) is higher, and continues monitoring that rail's voltage. If only 3.3VIN is present, the 5V RST output remains inactive (high), while 3.3V RST responds to out-of-tolerance conditions. This behavior makes DS1834S+T&R suitable for partial-power systems or staged power-up sequences.

What is the purpose of the PBRST pin on the DS1834S+T&R, and how is it debounced?

The PBRST pin on the DS1834S+T&R provides a hardware-managed manual reset override. It features an internal 40 kΩ pull-up to the higher of 5VIN or 3.3VIN and integrated digital debouncing circuitry. A low pulse ≥2 ms on PBRST forces both RST outputs active for ~350 ms after release - eliminating need for external RC networks or firmware polling. This ensures DS1834S+T&R delivers deterministic, glitch-immune reset initiation in field-service or user-initiated recovery scenarios.