Analog Devices Inc./Maxim Integrated DS5250F-825+

Overview

DS5250F-825+ from Maxim Integrated is a secure 8051-compatible microcontroller with hardware-accelerated single/3DES encryption, 256-byte scratchpad RAM, 5KB internal SRAM, and on-chip real-time clock - designed as the cryptographic engine for PIN pads and financial terminals requiring tamper-resistant program execution.

For engineers reviewing the DS5250F-825+ datasheet, DS5250F-825+ pinout, DS5250F-825+ application, or DS5250F-825+ equivalent, key selection factors include its 4-clock-per-cycle architecture, 25MHz max operating frequency, dual data pointers, secure-loader mode, and integrated modulo-arithmetic accelerator for public-key operations.

Technical Context

The DS5250F-825+ implements a hardened 8051 core with four clocks per machine cycle, enabling single-cycle instruction execution in 160ns at 25MHz. It integrates dedicated security peripherals including a 4096-bit modulo-arithmetic accelerator (MAA), true random-number generator (RNG), and tamper sensors for thermal/voltage/probe attack detection.

Memory protection is enforced via partitionable segments (4KB–256KB), hardware-based DES/3DES encryption of program and optional data memory, and program memory integrity checking. Its secure-loader mode and two self-destruct inputs enable irreversible response to physical intrusion attempts.

Key Specifications

Pinout & Package

DS5250F-825+ is housed in an 80-pin MQFP (Metric Quad Flat Package) with 0.5mm pitch, RoHS-compliant and lead-free. The package supports surface-mount assembly and thermal management suitable for embedded financial terminal designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS5250F-825+, DS5250F-8N5+ offers identical security functionality with extended thermal tolerance, while MAX32590 provides broader cryptographic agility and modern ISA support but lacks native 3DES and MAA - making DS5250F-825+ irreplaceable for EMV-certified PIN pad legacy compliance.

Availability

DS5250F-825+ is available at Aetrix Electronics and suitable for PIN pad systems, financial transaction terminals, and secure firmware update gateways requiring stable component supply and long-term lifecycle assurance.

Supply support for DS5250F-825+ 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 secure ICs for industrial, medical, communications, and financial applications.

The DS5250F-825+ belongs to Maxim's secure microcontroller family engineered specifically for tamper-resistant financial transaction systems where cryptographic integrity, physical attack resilience, and regulatory compliance (e.g., PCI PTS, FIPS 140-2) are mandatory.

FAQ

What is the maximum operating frequency of the DS5250F-825+?

The DS5250F-825+ operates at up to 25MHz, delivering single-cycle instruction execution in 160ns. This speed is validated across its full 0°C to +70°C commercial temperature range and enables real-time DES/3DES processing required for PIN block encryption in financial terminals. The DS5250F-825+ achieves this performance using a four-clocks-per-machine-cycle architecture distinct from standard 8051 derivatives.

Does the DS5250F-825+ include hardware support for public-key cryptography?

Yes, the DS5250F-825+ integrates a dedicated 4096-bit modulo-arithmetic accelerator (MAA) optimized for RSA and ECC operations. This hardware block performs modular exponentiation and multiplication independently of the CPU, significantly accelerating key generation and digital signature workflows. The DS5250F-825+ uses this MAA alongside its true random-number generator to produce FIPS 186-4–compliant cryptographic keys.

How does the DS5250F-825+ protect against physical tampering?

The DS5250F-825+ incorporates multiple tamper-detection mechanisms: voltage monitors, thermal sensors, and probe-detection circuitry. When triggered, these activate programmable countermeasures - including zeroization of sensitive memory and assertion of self-destruct inputs. These features are documented in the DS5250F-825+ datasheet and align with FIPS 140-2 Level 3 physical security requirements for cryptographic modules.

Is the DS5250F-825+ pin-compatible with other variants in the DS5250 family?

Yes, the DS5250F-825+ shares identical 80-pin MQFP packaging and pinout with DS5250F-825, DS5250F-8N5, and DS5250F-8N5+. All share the same signal mapping, power domains, and I/O configuration - allowing direct substitution in existing PCB layouts when thermal or RoHS requirements change. The DS5250F-825+ differs only in lead-free compliance and screening grade, not connectivity.

What memory resources are available on the DS5250F-825+?

The DS5250F-825+ provides 5KB of internal SRAM (with optional 1KB stack), 2KB of battery-backed SRAM for RTC and critical state retention, 1KB instruction cache, and supports up to 4MB each of external program and data memory. All external memory accesses are subject to hardware-enforced memory segmentation and encryption - ensuring that DS5250F-825+ maintains confidentiality even when using off-chip storage.