Analog Devices Inc./Maxim Integrated DS1830S+T&R

Overview

DS1830S+T&R from Maxim Integrated is a 5V precision reset sequencer IC that monitors VCC for out-of-tolerance conditions and generates three time-sequenced, open-drain active-low reset outputs (RST1, RST2, RST3) with programmable delays. It features pushbutton reset input (PBRST), tolerance-select input (TOL), and time-delay-select input (TD), operating across -40°C to +85°C in 8-pin SO package. Used in multi-rail power-up sequencing for microcontroller-based industrial control systems.

For engineers reviewing the DS1830S+T&R datasheet, DS1830S+T&R pinout, DS1830S+T&R application, or DS1830S+T&R equivalent, key selection criteria include VCC trip point accuracy (±0.12V at 4.62V typ), TD-selectable reset timing (10/20/50ms min for RST1), TOL-configurable voltage tolerance (5%/10%/15%), and guaranteed operation down to 1.0V supply.

Technical Context

The DS1830S+T&R implements a precision temperature-compensated voltage reference and comparator to detect VCC deviations, generating an internal power-fail signal that initiates reset assertion. Its sequenced release-RST1 first, then RST2 after 5× RST1 delay, then RST3 after 10× RST1 delay-enables controlled power-up of cascaded logic, memory, and processor rails.

Reset timing is determined by an on-chip oscillator and clock chain, with TD input selecting one of three fixed delay families (GND=10ms/50ms/100ms; NC=20ms/100ms/200ms; VCC=50ms/250ms/500ms). The TOL input sets VCC trip threshold (4.50–4.74V for DS1830 variant) and is latched during power-up before VCC exceeds the lowest trip value.

Key Specifications

Pinout & Package

DS1830S+T&R is housed in an 8-pin SOIC (150-mil width) package with standard JEDEC MS-012AC footprint and 1.27mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar reset sequencing applications.

Compared with MAX6326US29D3+ and TPS3808G33DBVR, the DS1830S+T&R uniquely delivers three programmable, cascaded reset outputs in a single 8-pin SO package-enabling deterministic multi-rail startup without external timing elements or firmware intervention.

Availability

DS1830S+T&R is available at Aetrix Electronics and suitable for industrial automation, embedded computing, and communications equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for DS1830S+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

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for industrial, automotive, and communications applications, emphasizing reliability, integration, and performance under harsh conditions.

The DS1830S+T&R belongs to Maxim's power-supply monitoring and reset IC product line, engineered specifically for deterministic, hardware-controlled power-up sequencing in multi-voltage embedded systems.

FAQ

What is the function of the TD pin on the DS1830S+T&R?

The TD pin on the DS1830S+T&R selects the base timing family for reset sequencing: grounded = 10ms (RST1), 50ms (RST2), 100ms (RST3); floating = 20/100/200ms; tied to VCC = 50/250/500ms. This hardware-selectable delay eliminates external timing components and ensures deterministic release order. The DS1830S+T&R samples TD only during initial power-up before VCC exceeds the lowest trip threshold, locking the timing configuration for the entire power cycle.

Does the DS1830S+T&R support 3.3V systems?

No, the DS1830S+T&R is the 5V variant of the DS1830/A family and has a nominal VCC trip point of 4.62V (range 4.50V–4.74V when TOL=VCC). For 3.3V systems, the DS1830AS+T&R or DS1830AU+T&R variants are specified with 3.06V typical trip point. Using DS1830S+T&R on a 3.3V rail would result in continuous reset assertion since VCC remains below the minimum trip threshold. Always match the DS1830x part number suffix (S/U for package, blank/A for voltage grade) to the target supply.

How does the TOL pin affect the DS1830S+T&R's voltage detection accuracy?

The TOL pin configures the DS1830S+T&R's VCC trip hysteresis: TOL=VCC selects ±5% tolerance (4.50–4.74V), TOL=GND selects ±10% (4.25–4.49V), and TOL=open selects ±15% (4.00–4.24V). This allows system designers to align trip point uncertainty with their regulator's output tolerance and board-level noise margin. The DS1830S+T&R latches the TOL state during power-up before VCC rises above the lowest possible trip value, ensuring consistent behavior across power cycles.

Can the DS1830S+T&R be used in cascade configurations?

Yes, the DS1830S+T&R supports cascade configurations where RST3 of a master device drives the PBRST input of a slave device, extending sequencing to six or more reset stages. To ensure proper ripple-through behavior, the master's VCCTP must be set higher than the slave's (e.g., master TOL=VCC, slave TOL=GND), so the master detects undervoltage first and triggers the slave's manual reset path. This configuration maintains timing integrity without additional logic, and the DS1830S+T&R's internal 40kΩ PBRST pull-up simplifies inter-stage wiring.

What is the maximum sink current capability of the DS1830S+T&R's reset outputs?

The DS1830S+T&R's RST1, RST2, and RST3 outputs are open-drain and rated for 20mA sink current at 0.4V output voltage, per DC Electrical Characteristics table. This allows direct driving of standard TTL/CMOS inputs or interfacing with higher-current loads via external pull-up resistors. The 20mA rating ensures compatibility with common microcontroller reset pins (typically requiring <100µA hold current) and enables robust noise immunity in electrically noisy industrial environments. Each output operates independently and retains its timing relationship regardless of load within specification.