Analog Devices Inc./Maxim Integrated DS1817-5/T&R

Overview

DS1817-5/T&R from Maxim Integrated (now Analog Devices) is a precision voltage-monitoring supervisory IC that provides active-high reset signaling for microprocessors during power failure or brownout events. It features a 3.0V ±5% VCC trip point (2.98V–3.15V), 150ms reset pulse width, push-pull output, and operates from -40°C to +85°C in SOT-23 package - used in embedded systems requiring reliable power-on reset and supply monitoring.

For engineers reviewing the DS1817-5/T&R datasheet, DS1817-5/T&R pinout, DS1817-5/T&R application, or DS1817-5/T&R equivalent, key selection criteria include its fixed 5% tolerance threshold, guaranteed 150ms reset hold time after VCC recovery, push-pull output drive capability (350µA high, 10mA low), and compatibility with 3.0V and 3.3V systems.

Technical Context

The DS1817-5/T&R integrates a temperature-compensated voltage reference and comparator to detect VCC deviations beyond ±5% of nominal 3.0V. Its internal circuitry asserts RST immediately upon out-of-tolerance detection and sustains it for 100–250ms (typ. 150ms) after VCC returns to spec, ensuring processor stabilization.

It uses CMOS output stage with push-pull configuration, eliminating need for external pull-up resistors. The device draws only 28–35µA quiescent current and supports VCC from 1.2V to 5.5V, enabling use across wide-input-voltage applications while maintaining accurate trip-point performance.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package (3.0mm × 1.7mm × 1.3mm body height), JEDEC MO-178 compatible, tape-and-reel format (T&R).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G01DBVR and MAX6326UT46D3+, the DS1817-5/T&R delivers plug-and-play 3.0V ±5% monitoring in minimal footprint with zero external components - ideal for cost-sensitive, space-constrained 3.3V embedded systems where fixed threshold suffices.

Availability

DS1817-5/T&R is available at Aetrix Electronics and suitable for industrial automation, smart metering, medical handhelds, and automotive infotainment systems requiring stable component supply and long-term manufacturability.

Supply support for DS1817-5/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

Analog Devices (acquired Maxim Integrated in 2021) designs high-performance analog, mixed-signal, and power management ICs for precision sensing, signal conditioning, and system supervision.

The DS1817-5/T&R belongs to Maxim's EconoReset™ family - engineered for cost-effective, single-chip power monitoring and reset generation in resource-constrained microprocessor systems.

FAQ

What is the exact VCC trip point range for DS1817-5/T&R?

The DS1817-5/T&R has a guaranteed VCC trip point range of 2.98V to 3.15V at -40°C to +85°C, corresponding to ±5% tolerance around 3.0V. This specification is measured under recommended operating conditions and reflects the voltage at which the RST output transitions from inactive to active state during power-down events. The DS1817-5/T&R uses an internal temperature-compensated reference to maintain this accuracy across its full operating temperature range.

Does DS1817-5/T&R require an external pull-up resistor on the RST pin?

No, DS1817-5/T&R does not require an external pull-up resistor because it features a push-pull output stage. The RST pin actively drives high during reset assertion and actively pulls low when released, providing full CMOS logic-level compliance without external components. This reduces BOM count and PCB area versus open-drain alternatives like the MAX6326 series. The DS1817-5/T&R's push-pull architecture is confirmed in its block diagram and electrical specifications.

What is the reset pulse width behavior of DS1817-5/T&R during power-up?

During power-up, DS1817-5/T&R holds RST active for 100–250ms (typical 150ms) after VCC crosses the trip threshold, ensuring the power supply and microprocessor stabilize before release. This timing is internally generated and independent of external capacitance. The DS1817-5/T&R's datasheet specifies tRPU (VCC detect to RST release) under 2.7V–3.3V conditions, confirming consistent behavior across typical 3.3V system rails.

Can DS1817-5/T&R operate with VCC below 3.0V?

Yes, DS1817-5/T&R operates with VCC from 1.2V to 5.5V per its recommended DC operating conditions, but its 3.0V ±5% trip point remains valid only when VCC is ≥2.98V. Below that, the device may not assert reset reliably. The DS1817-5/T&R's internal reference and comparator remain functional down to 1.2V, enabling use in low-VCC backup domains - however, trip accuracy is specified only within the 2.98V–3.15V window.

Is DS1817-5/T&R pin-compatible with other DS1817 variants like DS1817-10/T&R?

Yes, DS1817-5/T&R is pin-compatible with DS1817-10/T&R and DS1817-20/T&R - all share identical SOT-23-3 pinout (RST/VCC/GND) and package dimensions. The only difference is the factory-trimmed VCC trip point: ±5%, ±10%, or ±20%. This allows direct substitution in designs where tolerance requirements change, without PCB layout modification. The DS1817-5/T&R's marking code "D" (per datasheet table) confirms its 5% variant identity.