Analog Devices Inc./Maxim Integrated DS1815-20+

Overview

DS1815-20+ from Maxim Integrated (now Analog Devices) is a precision voltage-monitoring reset supervisor IC with push-pull output, designed for microprocessor power-fail detection and reset assertion. It features a 2.55 V nominal VCC trip point (±20% tolerance), 150 ms reset pulse width, and operates from 0 V to 5.5 V supply across –40°C to +85°C. Used in embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the DS1815-20+ datasheet, DS1815-20+ pinout, DS1815-20+ application, or DS1815-20+ equivalent, key selection criteria include its fixed 20% VCC threshold, push-pull RST output capable of sourcing 350 µA and sinking 10 mA, and guaranteed 100–250 ms reset hold time after VCC recovery.

Technical Context

The DS1815-20+ integrates a temperature-compensated bandgap reference and comparator to monitor VCC against a factory-trimmed 2.55 V threshold (2.47 V min / 2.64 V max). Its internal timing circuit ensures reset remains asserted for ≥100 ms and ≤250 ms after VCC returns to tolerance - independent of VCC slew rate or noise.

No external components are required: the device self-generates reset timing and delivers a clean, rail-to-rail push-pull RST signal that drives directly into microcontroller reset inputs without pull-up resistors. It asserts reset down to 0 V on VCC, enabling valid reset during full power collapse.

Key Specifications

Pinout & Package

DS1815-20+ is available in TO-92 and SOT-23 packages. Both variants share identical 3-pin configuration and functional pin mapping.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326–25D and TPS3808G125, the DS1815-20+ offers a factory-trimmed 2.55 V threshold with no external components, push-pull drive, and guaranteed 150 ms reset hold - ideal for cost-sensitive, space-constrained 3.3 V systems requiring zero-BOM supervision.

Availability

DS1815-20+ is available at Aetrix Electronics and suitable for industrial control, smart metering, medical handhelds, and automotive body electronics requiring stable component supply and long-term lifecycle support.

Supply support for DS1815-20+ 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 reliability-critical systems.

The DS1815-20+ belongs to Maxim's EconoReset family - low-cost, single-supply reset supervisors targeting cost-sensitive embedded applications where simplicity, small footprint, and guaranteed reset timing are essential.

FAQ

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

The DS1815-20+ has a factory-trimmed VCC trip point of 2.55 V, with a guaranteed range of 2.47 V to 2.64 V across –40°C to +85°C. This 20% tolerance is fixed and unadjustable, making DS1815-20+ suitable for systems where a known margin above typical 3.3 V rail dropout is required.

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

No. DS1815-20+ features a push-pull output stage that actively drives RST high and low. Unlike open-drain reset supervisors, DS1815-20+ eliminates the need for an external pull-up resistor, reducing BOM count and improving noise immunity in electrically noisy environments.

How long does DS1815-20+ hold the reset signal active after VCC recovers?

DS1815-20+ holds RST active for 100–250 ms after VCC returns to within tolerance. The typical value is 150 ms, ensuring sufficient time for power supply and microprocessor stabilization before release. This timing is internally generated and independent of external components or VCC slew rate.

Can DS1815-20+ operate with VCC below 1.0 V?

Yes. DS1815-20+ functions down to 0 V on VCC and asserts RST validly throughout full power collapse. Its internal circuitry remains operational and continues monitoring until VCC reaches the 2.47–2.64 V trip window, making DS1815-20+ uniquely suited for fail-safe reset during deep brownouts.

Is DS1815-20+ compatible with both TO-92 and SOT-23 PCB footprints?

DS1815-20+ is offered in both TO-92 and SOT-23 packages, but they are not footprint-compatible. Each variant requires its own dedicated land pattern. Pin numbering and electrical function are identical (RST/VCC/GND), but mechanical dimensions, thermal characteristics, and assembly processes differ - design files must match the selected package variant of DS1815-20+.