Analog Devices Inc./Maxim Integrated DS1233M-5

Overview

DS1233M-5 from Maxim Integrated (now part of Analog Devices) is a precision voltage-monitoring microprocessor supervisory circuit in TO-92 or 8-pin SOIC package, featuring 4.375 V typical VCC trip point, 350 ms reset pulse width, and active-low open-drain RST output. It ensures reliable power-on reset for 68XXX/HC16-based embedded controllers in industrial control panels.

For engineers reviewing the DS1233M-5 datasheet, DS1233M-5 pinout, DS1233M-5 application, or DS1233M-5 equivalent, key selection criteria include trip voltage tolerance (±0.125 V), guaranteed reset hold time after power recovery, internal 5 kΩ pullup resistor, and compatibility with MC33064-family reset ICs in legacy designs.

Technical Context

The DS1233M-5 uses an internal temperature-compensated bandgap reference and comparator to detect VCC deviations against its fixed 4.25–4.49 V trip window. Its reset assertion logic includes hysteresis between high/low trip levels (VHTL = 4.75 V, VLTL = 4.00 V) to prevent chatter during brownout conditions.

Upon power-up, the device holds RST low for 200–500 ms (typ. 350 ms) regardless of VCC slew rate, ensuring sufficient stabilization time for microprocessors before release. The open-drain RST output supports wired-OR configurations and interfaces directly with 5 V TTL/CMOS inputs without external level-shifting.

Key Specifications

Pinout & Package

DS1233M-5 is available in TO-92 (3-pin) and 8-pin SOIC packages. Pin functions differ by package: TO-92 uses all three pins (RST/VCC/GND); SOIC has four active pins (RST/VCC/GND/NC) with four no-connect terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and MC33064DR2G, the DS1233M-5 provides tighter trip accuracy (±0.125 V vs. ±5%), integrated pullup, and guaranteed 350 ms reset hold-making it optimal for 5 V systems requiring robust brownout immunity and BOM reduction.

Availability

DS1233M-5 is available at Aetrix Electronics and suitable for industrial PLC controllers, legacy automotive ECUs, medical diagnostic instruments, and point-of-sale terminals requiring stable component supply across extended product lifecycles.

Supply support for DS1233M-5 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 and mixed-signal ICs for industrial, communications, and computing applications.

The DS1233M-5 belongs to the EconoReset family of supervisory circuits engineered specifically for cost-sensitive, high-reliability microprocessor reset applications in legacy and industrial systems.

FAQ

What is the exact VCC trip voltage range for DS1233M-5?

The DS1233M-5 has a specified VCC trip point range of 4.25 V (minimum) to 4.49 V (maximum), with a typical value of 4.375 V. This narrow window ensures precise detection of 5 V supply collapse while rejecting noise-induced false triggers. The DS1233M-5 achieves this using an internal temperature-compensated voltage reference, making it suitable for environments with thermal cycling.

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

No, the DS1233M-5 includes an internal 5 kΩ pullup resistor on the RST pin, eliminating the need for an external component in most standard TTL/CMOS interface configurations. However, if driving heavy capacitive loads or multiple inputs, an external pullup may still be necessary-always verify RST rise time under actual load conditions per the DS1233M-5 datasheet timing specifications.

Can DS1233M-5 replace MC33064 in existing designs?

Yes, the DS1233M-5 is pin-function compatible with MC33064 in both TO-92 and SOIC packages and shares identical reset timing behavior. While MC33064 has a looser ±5% trip tolerance (4.5 V nominal), the DS1233M-5 offers tighter accuracy (±0.125 V around 4.375 V) and adds an internal pullup. No PCB changes are required for TO-92 variants; SOIC versions retain NC pin alignment.

What is the reset pulse width specification for DS1233M-5?

The DS1233M-5 guarantees a reset pulse width of 200 ms (minimum) to 500 ms (maximum), with a typical value of 350 ms. This duration begins when VCC returns to within tolerance and ensures sufficient stabilization time for microprocessors and peripheral ICs before releasing the reset signal. The DS1233M-5 maintains this timing across its full -40°C to +85°C operating temperature range.

Is DS1233M-5 compatible with 3.3 V microcontrollers?

Yes, the DS1233M-5 supports supply voltages from 1.2 V to 5.5 V and its open-drain RST output is compatible with 3.3 V logic inputs when used with an appropriate pullup voltage (e.g., 3.3 V). However, its 4.375 V trip point targets 5 V systems; for 3.3 V rails, consider DS1233M-3 (2.72 V typical trip) or MAX809 variants instead of DS1233M-5.