Analog Devices Inc./Maxim Integrated DS1816R-20-U

Overview

DS1816R-20-U from Maxim Integrated (now Analog Devices) is a precision voltage-monitoring supervisory IC that provides active-low reset output for microprocessor systems. It features 20% VCC trip tolerance (2.47V–2.64V), 150ms reset pulse width, open-drain RST output with internal 5kΩ pull-up, and operates from -40°C to +85°C in SOT-23 package - used in 3V embedded power-up sequencing and brownout protection.

For engineers reviewing the DS1816R-20-U datasheet, DS1816R-20-U pinout, DS1816R-20-U application, or DS1816R-20-U equivalent, key selection criteria include trip point accuracy, reset timeout stability, open-drain drive capability, thermal operating range, and compatibility with 3V logic-level microcontrollers requiring reliable power-fail detection.

Technical Context

The DS1816R-20-U integrates a temperature-compensated voltage reference and comparator to detect VCC deviations beyond ±20% of nominal 3V supply. Its internal circuitry asserts RST low on out-of-tolerance detection and holds it active for 100–250ms after VCC recovery, ensuring processor stabilization.

It uses an open-drain output stage with guaranteed 10mA sink capability at 0.4V, supports VCC from 1.2V to 5.5V, and exhibits typical operating current of 28–35µA - enabling low-power, self-contained reset supervision without external timing components or bias networks.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant, with gull-wing leads and exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-monitoring reset applications.

Compared with TPS3808G12DBVR and MAX6326UR29D3+T, the DS1816R-20-U delivers integrated pull-up, 20% trip tolerance optimized for 3V systems, and simpler board-level integration - making it ideal for cost-sensitive industrial and metering designs where fixed 150ms reset hold and robust brownout response are prioritized.

Availability

DS1816R-20-U is available at Aetrix Electronics and suitable for industrial PLC I/O modules, smart meter power management, medical sensor nodes, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for DS1816R-20-U 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 (via acquisition of Maxim Integrated) designs high-performance analog, mixed-signal, and power management ICs for precision sensing, signal conditioning, and system supervision.

The DS1816R-20-U belongs to the EconoReset™ family - engineered for cost-effective, single-chip power monitoring and reset generation in resource-constrained embedded systems with 3V supply rails.

FAQ

What is the exact VCC trip point range for DS1816R-20-U?

The DS1816R-20-U has a guaranteed VCC trip point range of 2.47V (minimum) to 2.64V (maximum) at -40°C to +85°C, corresponding to ±20% tolerance around a nominal 3.0V supply. This range is specified in the DC Electrical Characteristics table and validated across temperature and process corners - critical for reliable brownout detection in 3V systems.

Does DS1816R-20-U require an external pull-up resistor on the RST pin?

No, DS1816R-20-U includes an internal pull-up resistor of 3.5–7.5kΩ (typical 5kΩ) on the RST pin, eliminating the need for an external component in most applications. External pull-up may be added only if higher voltage levels or faster rise times are required - e.g., driving long PCB traces or high-capacitance inputs.

What is the reset timeout behavior of DS1816R-20-U during power-up?

During power-up, DS1816R-20-U asserts RST low until VCC reaches the trip threshold, then holds RST active for 100–250ms (typical 150ms) to allow system stabilization. This timeout is internally generated and independent of external components - ensuring consistent reset timing across units and temperatures.

Can DS1816R-20-U operate with a 1.8V supply?

Yes, DS1816R-20-U supports VCC from 1.2V to 5.5V per Recommended Operating Conditions. However, its 2.47–2.64V trip window means it will assert reset continuously below ~2.47V - so it functions as a valid supervisor only when the monitored rail is ≥2.47V, such as a 3V domain powered from a 1.8V source via LDO.

Is DS1816R-20-U pin-compatible with other DS181x series devices?

Yes, DS1816R-20-U shares identical SOT-23-3 pinout (RST-VCC-GND) and TO-92 pinout with all DS181x EconoReset variants (e.g., DS1816R-10-U, DS1816R-5-U). Only the trip tolerance differs - allowing drop-in replacement when system-level voltage margin permits, without PCB or firmware changes.