Analog Devices Inc./Maxim Integrated DS1830U

Overview

DS1830U 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 override, selectable VCC tolerance (5%/10%/15%), and TD-selectable timing (10/20/50 ms for RST1). Used in multi-rail power-up sequencing for microcontroller-based industrial control systems.

For engineers reviewing the DS1830U datasheet, DS1830U pinout, DS1830U application, or DS1830U equivalent, key selection considerations include its triple-reset sequencing capability, 5V trip point range (4.00–4.74 V depending on TOL), µSOP-8 package footprint, -40°C to +85°C operation, and compatibility with manual reset and power-fail warning requirements.

Technical Context

The DS1830U implements a precision temperature-compensated voltage reference and comparator to detect VCC deviations, generating an internal power-fail signal that triggers sequenced reset assertion. Its timing chain uses an internal oscillator to enforce fixed delay ratios: RST2 = 5×RST1, RST3 = 10×RST1, with RST1 delay set by TD (GND/NC/VCC) at 10/20/50 ms minimum.

Reset release follows strict power-up sequence logic: only after VCC stabilizes within tolerance does RST1 release first, followed by RST2, then RST3 - ensuring orderly system initialization. The TOL input is sampled only during power ramp-up below the lowest trip threshold and remains latched thereafter, preventing runtime reconfiguration.

Key Specifications

Pinout & Package

DS1830U is housed in an 8-pin µSOP (118-mil body width, 0.5 mm pitch), optimized for space-constrained industrial PCBs. Pin functions are validated per Maxim's official DS1830/A datasheet Rev. 060303.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6816 and TPS3808G33, the DS1830U uniquely delivers three programmable, ratioed reset outputs with integrated VCC monitoring and pushbutton support - making it irreplaceable in applications requiring deterministic multi-rail power-up coordination.

Availability

DS1830U is available at Aetrix Electronics and suitable for industrial PLCs, FPGA-based edge devices, automotive body controllers, and medical sensor hubs requiring stable component supply and long-term design-in support.

Supply support for DS1830U 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 computing applications, emphasizing reliability and integration.

The DS1830U belongs to Maxim's power-supply supervision product line, engineered specifically for deterministic multi-rail power-up sequencing in resource-constrained embedded systems.

FAQ

What is the VCC trip voltage range for DS1830U and how is it selected?

The DS1830U has a VCC trip range of 4.00 V to 4.74 V, determined by the TOL pin state: 4.00–4.24 V (TOL open, 15% tolerance), 4.25–4.49 V (TOL = GND, 10%), or 4.50–4.74 V (TOL = VCC, 5%). This selection occurs only during power-up before VCC exceeds the lowest trip threshold and remains latched. DS1830U is a 5V-specific device and does not support 3.3V operation.

How does the TD pin configure reset timing in DS1830U?

The TD pin sets the base delay for RST1: 10 ms (TD = GND), 20 ms (TD = open), or 50 ms (TD = VCC). RST2 and RST3 delays scale automatically at 5× and 10× RST1, respectively - e.g., TD = GND yields RST1 = 10 ms, RST2 = 50 ms, RST3 = 100 ms. All timing is generated by an internal oscillator, ensuring ratio consistency across temperature and supply.

Can DS1830U be used in a 3.3V system?

No. DS1830U is specified exclusively for 5V systems, with VCC trip points ranging from 4.00 V to 4.74 V. For 3.3V applications, the DS1830AU variant must be used - it provides matching functionality but with 2.47–3.15 V trip thresholds. Substituting DS1830U in a 3.3V design will result in continuous reset assertion due to undervoltage detection.

What is the function of the PBRST pin on DS1830U and what external components are needed?

PBRST is an active-low pushbutton reset input with internal 40 kΩ pull-up to VCC and integrated debouncing. A momentary switch to ground suffices - no external pull-up or RC filter is required. A ≥1 ms low pulse initiates a full reset cycle: all outputs go active, then release in sequence based on TD configuration. DS1830U maintains this behavior across its full -40°C to +85°C operating range.

Is DS1830U pin-compatible with DS1830S or DS1830?

Yes - DS1830U shares identical pinout and electrical functionality with DS1830 (DIP-8) and DS1830S (SO-8), differing only in package: µSOP-8 (118-mil width, 0.5 mm pitch). All three variants use the same pin assignment (PBRST, TD, TOL, GND, RST3, RST2, RST1, VCC) and support identical timing, tolerance, and reset sequencing behavior. Layout adaptation is required only for footprint differences.