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

Overview

DS1816R-20/T&R from Maxim Integrated (now Analog Devices) is a 3.3V supply voltage supervisor IC with open-drain active-low reset output, 20% VCC trip tolerance, 150ms reset timeout, and internal 5kΩ pull-up resistor. It monitors power integrity in microprocessor systems and automatically asserts reset during brownout or power failure.

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), guaranteed 100–250ms reset pulse width, -40°C to +85°C operation, SOT-23 package compatibility, and open-drain output drive capability up to 10mA.

Technical Context

The DS1816R-20/T&R implements a precision temperature-compensated voltage reference and comparator to detect VCC deviations beyond ±20% of nominal 3.3V. Its internal circuitry generates a power-fail signal that forces RST low immediately upon out-of-tolerance detection.

Upon VCC recovery, the device holds RST active for a minimum of 100ms (typical 150ms, max 250ms) to ensure stable power and processor initialization. The open-drain output includes an integrated 3.5–7.5kΩ pull-up resistor, eliminating external components in many designs.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package (3.0mm × 1.7mm × 1.3mm height), RoHS-compliant, tape-and-reel format (T&R). Pinout identical to TO-92 variant but optimized for automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with TPS3808G12DBVR and MAX6326UR29D3+T, the DS1816R-20/T&R offers integrated pull-up and fixed 150ms timing-reducing component count and design validation effort-while trading off adjustability and ultra-low ICC for cost-effective industrial reliability.

Availability

DS1816R-20/T&R is available at Aetrix Electronics and suitable for industrial control, smart metering, point-of-sale terminals, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

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

Analog Devices (via acquisition of Maxim Integrated) designs high-performance analog, mixed-signal, and power management ICs for precision sensing, power integrity, and real-time system control.

The DS1816R-20/T&R belongs to the EconoReset™ family of voltage supervisors, engineered for cost-sensitive industrial and consumer applications requiring reliable, single-chip power monitoring without external timing or bias 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 between 2.47V (minimum) and 2.64V (maximum) at -40°C to +85°C, corresponding to ±20% of 3.3V nominal. This range is specified in the DC Electrical Characteristics table under VCCTP for the "-20" variant and is validated across temperature and supply conditions.

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

No - DS1816R-20/T&R integrates a 3.5–7.5kΩ internal pull-up resistor on the open-drain RST output. An external pull-up is only needed if the target microcontroller's input leakage or capacitive load exceeds the internal resistor's capability to maintain valid VOH under worst-case conditions.

What is the reset timeout duration of DS1816R-20/T&R after VCC returns to tolerance?

The DS1816R-20/T&R holds the RST pin active low for 100ms (minimum), 150ms (typical), and 250ms (maximum) after VCC recovers to within its 20% trip window. This timing is fully characterized and independent of external components, enabling predictable microprocessor startup sequencing.

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

Yes - DS1816R-20/T&R functions across a VCC range of 0V to 5.5V and monitors any rail within that span. Its 2.47–2.64V trip window makes it suitable for 3V systems, but the device itself draws power and operates correctly even when VCC is as low as 1.2V, per Recommended Operating Conditions.

Is DS1816R-20/T&R compatible with both SOT-23 and TO-92 packages?

DS1816R-20/T&R is specifically the SOT-23-3 tape-and-reel variant. While the DS1816 family includes TO-92 versions (e.g., DS1816R-20), the "/T&R" suffix and part marking confirm this is the SOT-23 package. Pinout and electrical specs are identical between packages, but mechanical fit and assembly process differ.