Analog Devices Inc./Maxim Integrated DS1233M-5+TR

Overview

DS1233M-5+TR from Maxim Integrated (now Analog Devices) is a precision voltage-monitoring microprocessor supervisory circuit in 8-pin SOIC package, featuring 4.375 V typical reset threshold, 350 ms reset pulse width, and active-low open-drain RST output. It monitors VCC for out-of-tolerance conditions and holds reset during power-up and brownout to ensure reliable microprocessor initialization in embedded control systems.

For engineers reviewing the DS1233M-5+TR datasheet, DS1233M-5+TR pinout, DS1233M-5+TR application, or DS1233M-5+TR equivalent, key selection considerations include its fixed 4.375 V trip point, guaranteed 200–500 ms reset timeout, internal 5 kΩ pullup, compatibility with Motorola 68XXX/HC16 families, and -40°C to +85°C industrial temperature range.

Technical Context

The DS1233M-5+TR implements a precision temperature-compensated voltage reference and comparator to detect VCC deviations against a fixed 4.375 V nominal trip point (4.25–4.49 V min/max). Its internal power-fail logic asserts RST low on undervoltage and maintains it for ≥200 ms after VCC recovery.

It delivers an open-drain active-low reset signal with 8 mA sink capability at 0.4 V, supports supply voltages from 1.2 V to 5.5 V, and integrates a 5 kΩ internal pullup resistor - eliminating external components required by discrete reset solutions.

Key Specifications

Pinout & Package

DS1233M-5+TR is supplied in an 8-pin SOIC package (150 mil width), with pin 1 = RST (active-low reset output), pin 2 = VCC (power supply), pins 3–4 and 6–8 = NC (no connect), and pin 5 = GND (ground).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1233M-5+TR, MAX6326UT43D3+ offers smaller size but lacks internal pullup and shorter reset timing; TPS3808G33DBVR provides programmable delay and lower trip voltage but requires layout changes and different biasing - neither is pin-compatible, making DS1233M-5+TR optimal for legacy 8-pin SOIC designs needing fixed 4.375 V supervision.

Availability

DS1233M-5+TR is available at Aetrix Electronics and suitable for industrial PLC control, point-of-sale terminals, medical diagnostic instruments, and smart energy meters requiring stable component supply and long-term manufacturability.

Supply support for DS1233M-5+TR 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, automotive, and communications applications.

The DS1233M-5+TR belongs to the EconoReset™ family of microprocessor supervisory circuits, engineered to replace discrete reset solutions with integrated voltage monitoring, timing, and reset generation for cost-sensitive embedded systems.

FAQ

What is the exact reset voltage threshold of DS1233M-5+TR?

The DS1233M-5+TR has a nominal VCC trip point of 4.375 V, with guaranteed minimum and maximum values of 4.25 V and 4.49 V respectively over the full -40°C to +85°C operating temperature range. This fixed threshold is factory-trimmed and does not require external configuration. The DS1233M-5+TR is specifically calibrated for 5 V system supervision and is distinct from DS1233M-3 (2.72 V) or DS1233M-55 (4.625 V) variants.

Does DS1233M-5+TR require an external pullup resistor on the RST pin?

No, DS1233M-5+TR includes an internal 5 kΩ pullup resistor connected to VCC, enabling direct connection to microprocessor reset inputs without external components in most standard applications. However, if stronger pullup strength or voltage translation is needed (e.g., interfacing with 3.3 V logic while VCC = 5 V), an external resistor may be added - though the DS1233M-5+TR itself functions correctly with its internal pullup enabled.

Is DS1233M-5+TR pin-compatible with MC34064?

Yes, DS1233M-5+TR is explicitly documented as pin-function compatible with MC33064, MC34064, MC33164, and MC34164. Its 8-pin SOIC pinout matches these Motorola devices: Pin 1 = RST, Pin 2 = VCC, Pins 3–4/6–8 = NC, Pin 5 = GND. This allows direct substitution in existing designs without PCB modification, provided the 4.375 V trip point meets system requirements.

What is the reset timeout duration of DS1233M-5+TR after power returns to tolerance?

The DS1233M-5+TR guarantees a reset active time (tRST) of 200–500 ms after VCC returns to within tolerance, with 350 ms being the typical value. This interval ensures adequate stabilization of both the power supply and microprocessor clock domains before releasing the reset signal. The timing is internally generated and independent of external capacitors or resistors, delivering consistent behavior across temperature and supply variations.

Can DS1233M-5+TR operate from a 3.3 V supply?

Yes, DS1233M-5+TR supports supply voltages from 1.2 V to 5.5 V, including 3.3 V nominal rails. However, its 4.375 V trip point means it will assert reset whenever VCC falls below ~4.25 V - so it is intended for supervision of 5 V systems, not 3.3 V. When powered from 3.3 V, the DS1233M-5+TR will remain continuously in reset. For 3.3 V supervision, DS1233M-3 (2.72 V trip) or DS1233M-33 (3.08 V trip) variants should be used instead.