Analog Devices Inc./Maxim Integrated DS1815-20+T&R

Overview

DS1815-20+T&R from Maxim Integrated (now Analog Devices) is a precision voltage-monitoring supervisory IC that provides active-low reset assertion during power failure or out-of-tolerance VCC conditions. It features a 20% VCC trip point (2.47–2.64 V), 150 ms guaranteed reset pulse width, push-pull output, and operates from -40°C to +85°C in SOT-23 package - used for reliable microprocessor reset control in industrial power supplies.

For engineers reviewing the DS1815-20+T&R datasheet, DS1815-20+T&R pinout, DS1815-20+T&R application, or DS1815-20+T&R equivalent, key selection criteria include trip-point accuracy, reset timeout stability, push-pull drive capability, supply voltage range compatibility, and SOT-23 footprint suitability for space-constrained embedded systems.

Technical Context

The DS1815-20+T&R integrates a temperature-compensated voltage reference and comparator to detect VCC deviations beyond ±20% of nominal. Its internal circuitry asserts RST low when VCC falls below 2.47 V (min), holding it active for 100–250 ms after VCC recovers above 2.64 V (max).

It uses CMOS output stage with push-pull topology, delivering VOH ≥ VCC − 0.5 V at −500 µA and capable of sinking 10 mA at 0.4 V. Operating current is only 28–35 µA, enabling use in low-power battery-backed systems.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package (3.0 mm × 1.7 mm × 1.3 mm), RoHS-compliant, tape-and-reel format (T&R). Pin 1 = RST (active-low reset output), Pin 2 = VCC (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 MAX6326–29D2T+ and TPS3808G18DBVR, the DS1815-20+T&R delivers fixed ±20% trip accuracy with integrated push-pull drive in minimal SOT-23 footprint - reducing layout complexity and component count where 2.5 V nominal rail supervision is required.

Availability

DS1815-20+T&R is available at Aetrix Electronics and suitable for industrial automation, embedded metering, medical diagnostics, and point-of-sale terminal applications requiring stable component supply and long-lifecycle support.

Supply support for DS1815-20+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 system reliability.

The DS1815-20+T&R belongs to Maxim's EconoReset™ family - engineered for cost-sensitive, space-constrained applications requiring dependable power-on reset and brownout protection without external components.

FAQ

What is the exact VCC trip point range for DS1815-20+T&R?

The DS1815-20+T&R has a guaranteed VCC trip point range of 2.47 V (minimum) to 2.64 V (maximum), corresponding to ±20% tolerance around a nominal 3.3 V supply. This range is specified under DC electrical characteristics at -40°C to +85°C and is enabled by an internal temperature-compensated voltage reference. The DS1815-20+T&R maintains this accuracy without external calibration.

Does DS1815-20+T&R require an external pull-up resistor on the RST pin?

No, the DS1815-20+T&R features a push-pull output stage that actively drives both high and low states on the RST pin. It can source up to 350 µA at VCC − 0.1 V and sink up to 10 mA at 0.4 V, eliminating the need for an external pull-up resistor. This simplifies design and reduces BOM count compared to open-drain reset supervisors. The DS1815-20+T&R is fully functional with only VCC, GND, and RST connected.

What is the reset timeout duration of DS1815-20+T&R after VCC recovery?

The DS1815-20+T&R holds the RST pin active for 100–250 ms after VCC returns to within its trip threshold window. The typical value is 150 ms, as confirmed in AC electrical characteristics. This timeout is internally generated and independent of external capacitance, ensuring consistent reset timing across temperature and supply variations. The DS1815-20+T&R guarantees this behavior across its full operating range.

Can DS1815-20+T&R operate with a 1.8 V supply?

No, the DS1815-20+T&R is not specified to operate reliably at 1.8 V. Its recommended operating supply range is 0 V to 5.5 V, but the ±20% trip point (2.47–2.64 V) implies intended use with nominal 3.3 V rails. At 1.8 V, VCC falls below the lower trip threshold, causing continuous reset assertion. For 1.8 V systems, consider alternatives like TPS3808G18DBVR. The DS1815-20+T&R functions correctly only when VCC exceeds 2.64 V for normal operation.

Is DS1815-20+T&R available in TO-92 package?

No, the DS1815-20+T&R variant is exclusively offered in SOT-23-3 surface-mount package in tape-and-reel format (indicated by "+T&R" suffix). While the DS1815 family includes TO-92 versions (e.g., DS1815-20+), the specific part number DS1815-20+T&R denotes the SOT-23 packaged version optimized for automated assembly. Pinout is identical (RST/VCC/GND), but footprint and thermal characteristics differ. The DS1815-20+T&R is not interchangeable with through-hole variants without PCB redesign.