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 embedded systems requiring controlled power-up sequencing.

For engineers reviewing the DS1830U+ datasheet, DS1830U+ pinout, DS1830U+ application, or DS1830U+ equivalent, key selection criteria include its triple-reset sequencing capability, 5V trip point accuracy (±0.12 V), -40°C to +85°C operation, 8-pin µSOP package, and support for manual reset via PBRST with internal 40 kΩ pull-up.

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 reset assertion. Its sequenced release-RST1 first, then RST2 after 5× RST1 delay, then RST3 after 10× RST1 delay-enables orderly system boot across multiple voltage rails.

Reset timing is determined by the TD pin state (GND/N.C./VCC), with corresponding RST1 minimum delays of 10 ms, 20 ms, or 50 ms; all timing derives from an on-chip oscillator. The TOL pin selects VCC trip point tolerance (5%, 10%, or 15%) during power-up, sampled only while VCC remains below the lowest trip threshold.

Key Specifications

Pinout & Package

DS1830U+ is housed in an 8-pin µSOP (118-mil width) package with exposed pad for thermal performance and board-space efficiency in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT46D3+ and TPS3808G33DBVR, the DS1830U+ uniquely delivers three programmable, proportionally timed reset outputs in a single 8-pin µSOP, eliminating discrete timing networks and enabling deterministic multi-rail boot control not possible with single-output alternatives.

Availability

DS1830U+ is available at Aetrix Electronics and suitable for industrial PLC controllers, FPGA-based vision systems, medical imaging devices, and automotive infotainment head units 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, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The DS1830U+ belongs to Maxim's reset and supervisor product line, engineered specifically for reliable, sequenced power-up control in multi-voltage embedded systems where deterministic reset timing is critical.

FAQ

What is the VCC trip point range for DS1830U+ under TOL=VCC condition?

The DS1830U+ has a VCC trip point range of 4.50 V to 4.74 V when TOL is tied to VCC, corresponding to a nominal 5V supply with ±0.12 V tolerance. This specification is verified across the full operating temperature range (-40°C to +85°C) and ensures consistent detection of 5V rail undervoltage conditions. The DS1830U+ uses an internal temperature-compensated reference to maintain this accuracy without external calibration.

How does the TD pin affect reset timing in DS1830U+?

The TD pin on the DS1830U+ selects the base delay for RST1: grounding TD yields 10 ms minimum, leaving TD floating yields 20 ms, and connecting TD to VCC yields 50 ms. RST2 and RST3 delays scale directly as 5× and 10× the RST1 delay, respectively. This proportional timing eliminates need for external timing components and guarantees deterministic sequencing across temperature and voltage variations.

Can DS1830U+ be used with a 3.3V supply rail?

No, the DS1830U+ is specified exclusively for 5V operation and has a VCC trip point range centered at 4.62 V. For 3.3V systems, the pin-compatible DS1830AU+ variant must be used, which provides a 2.98–3.15 V trip point. Using DS1830U+ on a 3.3V rail would result in continuous reset assertion since VCC remains below the minimum trip threshold.

What is the function of the TOL pin on DS1830U+ and how is it sampled?

The TOL pin on DS1830U+ selects the VCC trip point tolerance: 5% (TOL=VCC), 10% (TOL=GND), or 15% (TOL=open). It is sampled only once during power-up, while VCC remains below the lowest potential trip value (e.g., <4.00 V for DS1830U+), and cannot be changed afterward. This one-time sampling prevents spurious reconfiguration during normal operation and ensures stable trip point selection.

Does DS1830U+ support manual reset, and what are the electrical requirements?

Yes, DS1830U+ supports manual reset via the PBRST pin, which is internally pulled up to VCC with a 40 kΩ resistor. A valid reset is initiated by pulling PBRST low for ≥1 ms; the device debounces the input internally. During assertion, all three reset outputs go active-low. Release of PBRST starts the sequenced timeout based on the TD setting, ensuring consistent behavior whether triggered by power event or user action.