Analog Devices Inc./Maxim Integrated DS1812-5+T&R

Overview

DS1812-5+T&R from Maxim Integrated is a 5V precision voltage supervisor IC with active-high push-pull reset output, 4.62 V typical V_CC trip point, 150 ms reset timeout, and -40°C to +85°C operating range. It monitors power supply integrity and automatically resets microprocessors during brownout or startup in embedded control systems.

For engineers reviewing the DS1812-5+T&R datasheet, DS1812-5+T&R pinout, DS1812-5+T&R application, or DS1812-5+T&R equivalent, key selection criteria include trip voltage tolerance (±0.12 V), guaranteed 100–300 ms reset assertion window, push-pull drive capability (350 µA high-level sink/source), low 30–40 µA quiescent current, and SOT-23-3 package compatibility with space-constrained PCB layouts.

Technical Context

The DS1812-5+T&R implements a temperature-compensated bandgap reference and comparator to detect V_CC deviations below 4.50–4.75 V. Its internal timing circuit ensures reset remains asserted for ≥100 ms after V_CC recovers to in-tolerance, meeting JEDEC JESD78 reliability requirements for microprocessor initialization.

It operates across 1.2–5.5 V supply range but is factory-trimmed for 5 V nominal systems (DS1812-5 variant). The push-pull output eliminates need for external pull-up resistors and supports direct interface to CMOS/TTL reset inputs without level-shifting.

Key Specifications

Pinout & Package

SOT-23-3 surface-mount package (3.0 mm × 1.4 mm × 1.1 mm height), lead-free and RoHS-compliant. Pin 1 = RST (active-high reset output), Pin 2 = V_CC (power supply input), Pin 3 = GND (ground reference).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G01DBVR and MAX809SEUR+T, the DS1812-5+T&R offers factory-set 5 V trip accuracy, push-pull output eliminating external components, and tighter trip tolerance (±0.12 V), making it optimal for cost-sensitive, space-constrained 5 V microcontroller reset applications where simplicity and reliability are prioritized.

Availability

DS1812-5+T&R is available at Aetrix Electronics and suitable for industrial automation, medical device power sequencing, point-of-sale terminals, and automotive body electronics requiring stable component supply and long-term manufacturability.

Supply support for DS1812-5+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, medical, and communications applications.

The DS1812-5+T&R belongs to Maxim's EconoReset™ family of voltage supervisors, engineered specifically for cost-effective, single-supply microprocessor reset generation in resource-constrained embedded systems.

FAQ

What is the exact V_CC trip voltage range for DS1812-5+T&R?

The DS1812-5+T&R has a guaranteed V_CC trip point range of 4.50 V (minimum) to 4.75 V (maximum), with 4.62 V typical. This specification applies across the full -40°C to +85°C operating temperature range and is factory-trimmed for 5 V nominal systems. The DS1812-5+T&R uses an internal temperature-compensated reference to maintain this accuracy without external calibration.

Does DS1812-5+T&R require an external pull-up resistor on the RST pin?

No, the DS1812-5+T&R features a push-pull active-high output that drives the RST pin directly. Unlike open-drain supervisors, it does not require an external pull-up resistor. This reduces BOM count and improves noise immunity in electrically noisy environments. The DS1812-5+T&R can source up to 350 µA and sink up to 10 mA on the RST pin.

What is the reset timeout duration of DS1812-5+T&R after V_CC returns to tolerance?

The DS1812-5+T&R holds the RST output active for 100 ms (minimum) to 300 ms (maximum) after V_CC rises above the trip threshold and stabilizes. The typical value is 150 ms. This timing is internally generated and does not depend on external capacitors or resistors, ensuring consistent reset behavior across units and temperature.

Can DS1812-5+T&R operate from a 3.3 V supply?

Yes, the DS1812-5+T&R operates from 1.2 V to 5.5 V, but its trip point is fixed at ~4.62 V. When powered from 3.3 V, the DS1812-5+T&R will assert reset continuously because V_CC remains below the trip threshold. It is intended for 5 V systems only - for 3.3 V supervision, consider DS1812-33 or other variants with matching trip points.

Is DS1812-5+T&R pin-compatible with MAX809 or TPS3808 series?

The DS1812-5+T&R shares the SOT-23-3 package and pinout (RST-V_CC-GND) with MAX809SEUR+T, enabling footprint reuse. However, it is not pin-compatible with TPS3808G01DBVR, which has different pin assignment (GND-V_CC-OUT). The DS1812-5+T&R's push-pull output also differs functionally from the open-drain outputs of both alternatives.