Analog Devices Inc./Maxim Integrated DS2250T-32-16

Overview

DS2250T-32-16 from Maxim Integrated is an 8-bit 8051-compatible soft microcontroller module with 32kB nonvolatile SRAM, 16MHz max crystal speed, and integrated real-time clock (RTC) powered by on-board crystal. It preserves program/data, configuration registers, and timekeeping for >10 years without VCC, enabling secure, power-fail-resilient embedded control in utility meters and industrial data loggers.

For engineers reviewing the DS2250T-32-16 datasheet, DS2250T-32-16 pinout, DS2250T-32-16 application, or DS2250T-32-16 equivalent, key selection considerations include nonvolatile RAM retention duration, RTC integration, serial bootstrap loader support, and 40-pin SIMM package compatibility with legacy 8051 development toolchains.

Technical Context

The DS2250T-32-16 implements a fully 8051-object-code-compatible CPU core with dual memory spaces: up to 32kB of nonvolatile SRAM usable for both program and data storage, plus dedicated RTC registers accessible via SFR bit ECE2 (MCON.2) to enable alternate memory mapping. Its oscillator supports external crystals up to 16MHz, with timing specifications validated for expanded bus operation at that frequency.

It features hardware-level security including encrypted software execution, programmable MCON register, and software lock/unlock commands (Z/U), alongside system-level reliability functions: power-fail reset, early-warning power-fail interrupt, and watchdog timer - all backed by nonvolatile preservation of state during VCC loss.

Key Specifications

Pinout & Package

DS2250T-32-16 uses a 40-pin SIMM package (2.65" × 2.385", 0.050" lead pitch) with industry-standard pinout compatible with 8051-based system designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar soft microcontroller applications.

Compared with DS2250-32-16, DS2250T-32-16 adds permanent RTC capability without increasing pin count or altering layout; versus DS2250T-64-16, it trades memory capacity for lower unit cost while retaining identical real-time and power-fail resilience features.

Availability

DS2250T-32-16 is available at Aetrix Electronics and suitable for smart metering, industrial data logging, secure access systems, and legacy controller upgrades requiring stable component supply and long-term lifecycle support.

Supply support for DS2250T-32-16 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) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal ICs for industrial, automotive, and communications markets.

The DS2250(T) product line delivers "soft" microcontrollers designed for applications demanding nonvolatile operation, secure firmware execution, and autonomous timekeeping without external support components.

FAQ

What is the nonvolatile data retention period for DS2250T-32-16 at room temperature?

The DS2250T-32-16 guarantees nonvolatile retention of program memory, data memory, configuration registers, and RTC information for over 10 years at 25°C ambient temperature with no applied VCC. This specification is measured under controlled conditions and reflects the intrinsic data retention capability of its embedded nonvolatile SRAM technology.

Does DS2250T-32-16 require an external crystal for real-time clock operation?

Yes, the DS2250T-32-16 includes an on-board crystal specifically for the real-time clock function. The RTC operates independently using this dedicated crystal, which is distinct from the main system crystal connected to XTAL1/XTAL2. No additional external crystal is needed for RTC functionality.

Can DS2250T-32-16 execute encrypted software, and how is security enabled?

Yes, DS2250T-32-16 supports encrypted software execution to prevent unauthorized disclosure. Security is enabled by loading a 40-bit encryption key via the serial bootstrap loader command 'K', then setting the security lock using command 'Z'. Once locked, program memory readback is disabled and only authenticated execution is permitted.

What are the supported baud rates for serial programming of DS2250T-32-16?

The DS2250T-32-16 serial bootstrap loader supports 300, 1200, 2400, and 9600 bps baud rates. Supported rates depend on the installed crystal frequency; for example, with a 11.0592MHz crystal, all four rates are available, while a 14.7456MHz crystal supports 300–9600 bps as documented in Table 2 of the datasheet.

Is DS2250T-32-16 pin-compatible with standard 8051 microcontrollers in 40-pin packages?

DS2250T-32-16 uses a 40-pin SIMM package with a pinout aligned to industry-standard 8051 functionality (e.g., P0–P3, RST, XTAL1/XTAL2, EA, ALE, PSEN), but differs in implementation details: Port 0 is open-drain, RST is active-high, and EA is internally pulled down. Direct substitution requires verification of these interface differences in the target design.