Analog Devices Inc./Maxim Integrated DS1816R-20+T&R

Overview

DS1816R-20+T&R from Maxim Integrated (now Analog Devices) is a 3.3V precision voltage-monitoring reset IC with open-drain output, 20% VCC trip tolerance, 150ms reset timeout, and -40°C to +85°C operation-used for reliable microprocessor power-fail detection and restart in embedded control systems.

For engineers reviewing the DS1816R-20+T&R datasheet, DS1816R-20+T&R pinout, DS1816R-20+T&R application, or DS1816R-20+T&R equivalent, key selection criteria include trip-point accuracy (2.47–2.64V), internal 5kΩ pull-up resistor, guaranteed 100–250ms active-low reset pulse width, and SOT-23/TO-92 package compatibility with space-constrained PCB layouts.

Technical Context

The DS1816R-20+T&R implements a temperature-compensated bandgap reference and comparator to detect VCC deviations beyond ±20% of nominal 3.3V. It asserts RST low on out-of-tolerance detection and holds it active for ≥100ms (typ. 150ms) after VCC recovery.

Its open-drain RST output supports wired-OR configurations and interfaces directly with microcontroller reset inputs. Internal 5kΩ pull-up eliminates external components in many designs, while IOL ≥10mA ensures robust drive into typical reset input capacitance and leakage.

Key Specifications

Pinout & Package

SOT-23 and TO-92 packages both provide identical 3-pin configuration: Pin 1 = RST (active-low open-drain reset output), Pin 2 = VCC (power supply input), Pin 3 = GND (ground reference).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326–26D and TPS3808G12DBVR, the DS1816R-20+T&R delivers optimized cost-performance trade-off for fixed 3V systems needing robust 20% tolerance, minimal BOM, and proven industrial temperature reliability-without external components or configuration overhead.

Availability

DS1816R-20+T&R is available at Aetrix Electronics and suitable for industrial PLCs, smart energy meters, automotive body controllers, and IoT edge sensor nodes requiring stable component supply and long-term lifecycle support.

Supply support for DS1816R-20+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 high-performance analog and mixed-signal ICs for industrial, automotive, communications, and computing markets.

The DS1816R-20+T&R belongs to the EconoReset™ family-engineered for cost-sensitive, space-constrained embedded systems requiring dependable power-on and power-fail reset functionality with minimal external components.

FAQ

What is the exact VCC trip voltage range for DS1816R-20+T&R?

The DS1816R-20+T&R has a guaranteed VCC trip point range of 2.47V (minimum) to 2.64V (maximum) at -40°C to +85°C, corresponding to its 20% tolerance specification for nominal 3.3V operation. This range is defined by internal precision voltage reference and comparator circuitry, and does not require external calibration. The DS1816R-20+T&R maintains this accuracy across its full operating temperature range.

Does DS1816R-20+T&R require an external pull-up resistor on the RST pin?

No, the DS1816R-20+T&R integrates a 3.5–7.5kΩ internal pull-up resistor on its open-drain RST output, eliminating the need for an external pull-up in most standard 3.3V or 5V microcontroller reset applications. An external pull-up may be added only if higher sink current or faster rise time is required beyond the internal resistor's capability. The DS1816R-20+T&R datasheet confirms this design feature in its DC electrical characteristics table.

How long is the reset signal held active after VCC returns to tolerance?

The DS1816R-20+T&R holds the RST signal active for 100–250ms after VCC recovers to within its trip threshold, with a typical duration of 150ms. This guaranteed minimum timeout ensures sufficient stabilization time for both the power supply and connected microprocessor before release. The timing is internally generated and independent of external RC networks. This behavior is explicitly specified in the DS1816R-20+T&R AC electrical characteristics table under "RESET Active Time (tRST)".

Can DS1816R-20+T&R operate with supply voltages below 3.3V?

Yes, the DS1816R-20+T&R supports supply voltages from 0V up to 5.5V and functions correctly across this full range. Its internal reference and comparator remain operational down to VCC = 1.2V, enabling use in low-voltage microcontroller systems or battery-depleted scenarios. The DS1816R-20+T&R trip point remains fixed relative to its 20% tolerance window regardless of VCC level, as confirmed in the recommended operating conditions and electrical characteristics sections of its datasheet.

What package types are offered for DS1816R-20+T&R?

The DS1816R-20+T&R is available in both SOT-23 and TO-92 packages, each with identical 3-pin pinout: Pin 1 = RST (active-low open-drain), Pin 2 = VCC, Pin 3 = GND. The SOT-23 variant offers space-saving surface-mount compatibility, while TO-92 supports through-hole prototyping and legacy board designs. Both packages share identical electrical specifications and thermal performance across -40°C to +85°C. The DS1816R-20+T&R marking "R" in the part number denotes the SOT-23 package per Maxim's standard ordering convention.