Analog Devices Inc./Maxim Integrated DS1233M-3

Overview

DS1233M-3 from Maxim Integrated (now Analog Devices) is a precision voltage-monitoring microprocessor supervisory circuit in TO-92 or 8-pin SOIC package, featuring a 2.72 V nominal VCC trip point, 350 ms reset pulse width, and active-low open-drain RST output. It monitors power supply integrity for embedded microcontrollers in industrial control systems requiring reliable power-on reset and brownout detection.

For engineers reviewing the DS1233M-3 datasheet, DS1233M-3 pinout, DS1233M-3 application, or DS1233M-3 equivalent, key selection criteria include trip threshold accuracy (±0.08 V), guaranteed reset hold time (200–500 ms), internal 5 kΩ pullup, compatibility with Motorola 68XXX/HC16 families, and -40°C to +85°C operating range.

Technical Context

The DS1233M-3 implements a temperature-compensated bandgap reference and comparator to detect VCC deviations below 2.64 V (min) or above 2.80 V (max), asserting RST low during out-of-tolerance conditions. Its internal timing circuit ensures reset remains active for ≥200 ms after VCC recovery, with typical 350 ms duration.

It operates across 1.2 V to 5.5 V supply range, draws only 50 µA quiescent current, and provides open-drain RST output capable of sinking 8 mA at 0.4 V - enabling direct interface to TTL/CMOS inputs without external pullup in many designs.

Key Specifications

Pinout & Package

Available in TO-92 (3-pin) and 8-pin SOIC packages. Pin functions are identical across variants except for NC pins in SOIC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326–L27 and TPS3808G33, the DS1233M-3 delivers longer guaranteed reset duration (200–500 ms vs. 140 ms or 200 ms min), eliminates external resistor networks for trip setting, and includes an internal 5 kΩ pullup - reducing design complexity for cost-sensitive industrial microcontroller systems.

Availability

DS1233M-3 is available at Aetrix Electronics and suitable for industrial control, smart metering, POS terminal, and medical device applications requiring stable component supply and long-term manufacturability.

Supply support for DS1233M-3 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 high-performance analog and mixed-signal semiconductors for industrial, automotive, and communications markets.

The DS1233M-3 belongs to the EconoReset™ family of supervisory circuits engineered specifically for cost-effective, reliable power-on reset and brownout protection in resource-constrained microcontroller systems.

FAQ

What is the exact VCC trip point specification for DS1233M-3?

The DS1233M-3 has a guaranteed VCC trip point range of 2.64 V (min) to 2.80 V (max), with 2.72 V typical. This threshold is factory-trimmed and temperature-compensated, making it suitable for monitoring 3 V supply rails where precise brownout detection is required. The DS1233M-3 datasheet specifies this value under DC electrical characteristics with note 1 referencing ground-referenced measurement conditions.

Does DS1233M-3 require an external pullup resistor on the RST pin?

The DS1233M-3 includes an internal 3.75–6.5 kΩ pullup resistor on the RST pin, eliminating the need for an external pullup in most TTL/CMOS interfacing scenarios. However, if driving high-capacitance nodes (>50 pF) or non-standard logic families, an external pullup may still be recommended per application requirements. The DS1233M-3 datasheet confirms this internal resistor in the DC electrical characteristics table.

Is DS1233M-3 pin-compatible with MC34064?

Yes, the DS1233M-3 is explicitly stated in its datasheet to be pin-function compatible with the MC33064, MC34064, MC33164, and MC34164. For TO-92 versions, all three pins match directly (RST, VCC, GND). In 8-pin SOIC, DS1233M-3 uses pins 1 (RST), 2 (VCC), and 4 (GND), matching MC34064's functional pinout despite differing pin counts - confirming functional drop-in capability in legacy designs using DS1233M-3.

What is the reset timeout behavior of DS1233M-3 during power-up?

Upon power-up, the DS1233M-3 asserts RST low until VCC reaches ≥2.64 V and remains asserted for a minimum of 200 ms (typical 350 ms, max 500 ms) to ensure microprocessor and power supply stabilization. This timing is internally generated and independent of external components. The DS1233M-3 timing diagram (Figure 3) and AC electrical characteristics table confirm tRST = 200–500 ms under -40°C to +85°C conditions.

Can DS1233M-3 operate with supply voltages below 3 V?

Yes, the DS1233M-3 supports supply voltages from 1.2 V to 5.5 V, verified across its full operating temperature range (-40°C to +85°C). Its 2.72 V trip point remains valid even when VCC is as low as 1.2 V, enabling use in ultra-low-voltage battery-backed systems. The DS1233M-3 datasheet lists this extended supply range in the Recommended DC Operating Conditions table, with note 1 confirming functionality down to 1.2 V.