Analog Devices Inc./Maxim Integrated DS1818-5+T&R

Overview

DS1818-5+T&R from Maxim Integrated is a 3.3V fixed-threshold supervisory IC with pushbutton reset capability, active-low open-drain reset output, 150ms reset timeout, and internal 5.5kΩ pullup resistor. It monitors VCC for power-fail detection and provides manual reset via external pushbutton in embedded microprocessor systems.

For engineers reviewing the DS1818-5+T&R datasheet, DS1818-5+T&R pinout, DS1818-5+T&R application, or DS1818-5+T&R equivalent, key selection criteria include reset threshold accuracy (2.98–3.15V), guaranteed 150ms reset pulse width, -40°C to +85°C operation, quiescent current ≤35µA, and SOT-23/TO-92 package compatibility.

Technical Context

The DS1818-5+T&R implements a precision temperature-compensated voltage reference and comparator to detect VCC deviations beyond ±5% of 3.3V. Its internal power-fail logic asserts RST within 5µs of out-of-tolerance detection and holds it active for 100–250ms after VCC recovery.

Pushbutton functionality operates independently: pulling RST low for ≥1µs triggers a manual reset cycle, after which the output remains low for 100–250ms. The open-drain output supports external pull-up configurations while its integrated 3.5–7.5kΩ resistor enables direct connection to most microcontroller reset inputs.

Key Specifications

Pinout & Package

DS1818-5+T&R is supplied in SOT-23 package (3-pin, surface-mount) and TO-92 package (3-pin, through-hole). Both variants share identical pin assignment and electrical behavior.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar supervisory IC applications.

Compared with MAX6326–33D and TPS3808G33DBVR, DS1818-5+T&R uniquely combines pushbutton reset support, internal pullup, and open-drain output in a single low-quiescent-current package-making it optimal for cost-sensitive, space-constrained 3.3V microcontroller systems requiring both power and manual reset control.

Availability

DS1818-5+T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, medical handheld diagnostics, smart energy meters, and automotive telematics modules requiring stable component supply and long-term lifecycle support.

Supply support for DS1818-5+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 precision analog, mixed-signal, and power management ICs for industrial, communications, computing, and consumer applications.

The DS1818-5+T&R belongs to Maxim's EconoReset family of supervisory ICs, engineered for simple, low-cost power monitoring and reset generation in resource-constrained microcontroller systems.

FAQ

What is the exact reset threshold voltage range for DS1818-5+T&R?

The DS1818-5+T&R has a guaranteed reset threshold range of 2.98V to 3.15V at 25°C, corresponding to ±5% of 3.3V. This specification is maintained across the full -40°C to +85°C operating temperature range due to its temperature-compensated internal reference. The DS1818-5+T&R datasheet confirms this range under DC Electrical Characteristics with test conditions VCC = 1.2V to 5.5V.

Does DS1818-5+T&R require an external pull-up resistor?

No, DS1818-5+T&R includes an internal pull-up resistor ranging from 3.5kΩ to 7.5kΩ, optimized for direct interface with standard 3.3V microcontroller reset inputs. External pull-up is only needed if higher sink current (>10mA) or different voltage level translation is required. The DS1818-5+T&R datasheet specifies that typical operation uses the internal resistor unless special drive strength is needed.

How does the pushbutton reset function work on DS1818-5+T&R?

The DS1818-5+T&R monitors its own RST pin: pulling it low for ≥1µs triggers a manual reset cycle, and the output remains actively low for 100–250ms after release. This eliminates external debounce components. The DS1818-5+T&R timing diagram (Figure 3) shows tPBRST = 100–250ms, and the feature is electrically independent of VCC monitoring.

What package types are available for DS1818-5+T&R?

DS1818-5+T&R is offered in both SOT-23 (surface-mount, tape-and-reel) and TO-92 (through-hole) packages. The "T&R" suffix in DS1818-5+T&R specifically denotes the SOT-23 variant supplied in tape-and-reel format. Pinout and electrical specifications are identical between packages, per the DS1818-5+T&R mechanical drawings and absolute maximum ratings table.

What is the maximum supply voltage and operating current for DS1818-5+T&R?

The DS1818-5+T&R supports VCC from 1.0V to 5.5V, with absolute maximum rating of +7.0V. Its quiescent current is specified as 28–35µA (typical to max) when RST is open and VCC < 5.5V. This low current enables use in always-on or battery-backed systems. All values are confirmed in the DS1818-5+T&R Recommended DC Operating Conditions and DC Electrical Characteristics tables.