Analog Devices Inc./Maxim Integrated DS1233A-15/T&R

Overview

DS1233A-15/T&R from Maxim Integrated is a 3.3V precision voltage-monitoring microprocessor reset supervisor IC with pushbutton debounce, 2.72V nominal VCC trip point (±15%), 350ms reset timeout, internal 5kΩ pull-up, and -40°C to +85°C operation. It ensures reliable power-on reset and manual reset in embedded microcontroller systems.

For engineers reviewing the DS1233A-15/T&R datasheet, DS1233A-15/T&R pinout, DS1233A-15/T&R application, or DS1233A-15/T&R equivalent, key selection criteria include VCC trip accuracy (2.64–2.80V), reset pulse duration (250–450ms), pushbutton release detection threshold (0.3–0.8V), and SOT-223/TO-92 package compatibility.

Technical Context

The DS1233A-15/T&R integrates a temperature-compensated voltage reference and comparator to monitor 3.3V supply integrity, asserting RESET when VCC falls below 2.72V (15% tolerance). Its dual-function architecture simultaneously handles power-fail detection and external pushbutton input via the same RST pin.

It implements a monostable timing circuit that holds RESET active for 350ms after VCC recovery or pushbutton release, with internal debouncing logic eliminating need for external RC networks. The device uses a single-pin bidirectional interface for both reset assertion and pushbutton sensing, relying on voltage thresholds (PBDV = 0.8–2.0V, PBRD = 0.3–0.8V) and edge detection.

Key Specifications

Pinout & Package

DS1233A-15/T&R is available in SOT-223 (4-pin) and TO-92 (3-pin) packages. The /T&R suffix indicates tape-and-reel packaging for automated assembly. Pin functions are identical across variants except for Pin 4 (GROUND) present only in SOT-223.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with MAX6326–264 and TPS3808G15, the DS1233A-15/T&R uniquely combines fixed 2.72V trip accuracy, integrated pushbutton debounce, and 350ms factory-set timeout in compact SOT-223/TO-92 packages-reducing design effort for cost-sensitive 3.3V microcontroller systems requiring both power and manual reset control.

Availability

DS1233A-15/T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, medical handheld diagnostics, smart energy meters, and automotive body control modules requiring stable component supply and long-term production continuity.

Supply support for DS1233A-15/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 DS1233A-15/T&R belongs to Maxim's EconoReset family-engineered for cost-effective, high-reliability power monitoring and reset control in resource-constrained microprocessor systems.

FAQ

What is the exact VCC trip voltage range for DS1233A-15/T&R?

The DS1233A-15/T&R has a guaranteed VCC trip point range of 2.64V to 2.80V at +25°C, corresponding to 15% tolerance around a nominal 2.72V threshold. This range is specified across the full operating temperature range (-40°C to +85°C) and ensures robust detection of 3.3V supply faults without false triggering.

Does DS1233A-15/T&R require an external capacitor on the RST pin?

Yes, DS1233A-15/T&R requires a capacitor between 100pF and 0.01µF connected from RST to ground for proper pushbutton operation. This capacitor enables internal debouncing logic; using less than 100pF may cause unreliable button detection, while exceeding 0.01µF can extend debounce time beyond specification.

Can DS1233A-15/T&R be used with a 5V microprocessor system?

No, DS1233A-15/T&R is specifically designed for 3.3V systems and has a trip range centered at 2.72V. For 5V applications, Maxim offers the DS1233-15 (trip ~4.125V); using DS1233A-15/T&R on 5V would result in immediate and continuous reset assertion due to overvoltage on VCC relative to its rating.

What is the function of Pin 4 in the SOT-223 package of DS1233A-15/T&R?

Pin 4 in the SOT-223 package of DS1233A-15/T&R is a dedicated GROUND terminal, electrically connected to Pin 1 internally. It improves thermal dissipation and reduces ground impedance in high-noise environments but does not carry unique signal functionality beyond enhancing stability.

How does DS1233A-15/T&R handle simultaneous power failure and pushbutton press?

DS1233A-15/T&R prioritizes power-fail detection: if VCC drops below trip voltage while a pushbutton is pressed, RESET remains asserted continuously. Once VCC recovers, the device initiates its 350ms timeout regardless of button state-ensuring deterministic reset sequencing without race conditions or ambiguous states.