Analog Devices Inc./Maxim Integrated DS2460S+T&R

Overview

DS2460S+T&R from Maxim Integrated is a dedicated SHA-1 coprocessor with 112-byte user EEPROM, designed for secure authentication in I²C-based host systems. It performs hardware-accelerated SHA-1 MAC generation, supports 100kHz/400kHz I²C communication, operates from 2.7V to 5.5V across –40°C to +85°C, and integrates three address inputs (AD0–AD2) for up to eight device addressing on one bus - used in electronic payment terminals and access control readers.

For engineers reviewing the DS2460S+T&R datasheet, DS2460S+T&R pinout, DS2460S+T&R application, or DS2460S+T&R equivalent, key selection considerations include its I²C slave address configurability, 200k-cycle EEPROM endurance per 8-byte block, 10ms max EEPROM write time, ±4kV IEC 1000-4-2 ESD rating, and SHA-1 computation support for token authentication and short-message encryption.

Technical Context

The DS2460S+T&R implements a fully autonomous SHA-1 engine that accepts up to 64 bytes of input data and produces a 20-byte MAC without host CPU intervention. Its I²C interface complies with standard- and fast-mode timing, including tHD:STA ≥ 0.6µs, tLOW ≥ 1.3µs, and fSCL up to 400kHz, with Schmitt-trigger inputs on AD0–AD2 and open-drain SDA/SCL pins requiring external pullups.

It features a dedicated 8-byte EEPROM write buffer, 112-byte user EEPROM organized in 14 × 8-byte blocks, and a fixed 64-bit unique registration number. The device uses no internal clock source - all timing is derived from the master's SCL - and does not support clock stretching, simplifying host timing control but requiring strict adherence to I²C bus idle conditions before START sequences.

Key Specifications

Pinout & Package

DS2460S+T&R is housed in an 8-pin SOIC (150 mils) RoHS-compliant package with gull-wing leads, compatible with standard surface-mount reflow profiles (peak 260°C). Pin 5 is NC (not connected); all other pins are electrically functional and defined per Maxim's abridged datasheet Rev. 3/10.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SHA-1 coprocessor applications.

Compared with ATSHA204A-TNGTLS and DS28E01-100+, the DS2460S+T&R offers I²C-native integration, configurable slave addressing, and optimized support for legacy SHA-1 authentication workflows - making it suitable where protocol compatibility, minimal host code changes, and multi-device bus scalability are prioritized over cryptographic algorithm evolution.

Availability

DS2460S+T&R is available at Aetrix Electronics and suitable for utility meters, electronic payment terminals, and access control systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for DS2460S+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 secure ICs for industrial, automotive, and communications applications - emphasizing reliability, security, and power efficiency.

The DS2460S+T&R belongs to Maxim's secure authentication product line, engineered specifically for hardware-accelerated cryptographic operations in resource-constrained I²C host systems - targeting anti-cloning, license enforcement, and data integrity verification.

FAQ

What is the primary function of the DS2460S+T&R in a secure system?

The DS2460S+T&R serves as a hardware SHA-1 coprocessor with integrated EEPROM, enabling secure authentication through MAC generation without host software implementation. It offloads SHA-1 computation, stores device-specific secrets in 112-byte EEPROM, and communicates via I²C - making DS2460S+T&R ideal for access control, payment terminals, and license management where cryptographic integrity is critical.

Does the DS2460S+T&R support both standard- and fast-mode I²C speeds?

Yes, the DS2460S+T&R supports I²C communication at 100kHz (standard-mode) and 400kHz (fast-mode), with timing compliance verified per I²C specification - including tLOW ≥ 1.3µs and tHD:STA ≥ 0.6µs. Its open-drain SDA and input-only SCL require external pullup resistors, and DS2460S+T&R does not perform clock stretching, simplifying timing design for host controllers.

How many devices can share the same I²C bus using DS2460S+T&R?

Up to eight DS2460S+T&R devices can operate on the same I²C bus segment, enabled by three binary address inputs (AD0, AD1, AD2) that configure distinct 7-bit slave addresses (1000101x to 1000111x). This eliminates address conflicts and removes the need for external multiplexers - a key advantage of DS2460S+T&R in multi-token or multi-peripheral authentication systems.

What is the EEPROM endurance and data retention specification for DS2460S+T&R?

The DS2460S+T&R provides 200,000 write cycles per 8-byte EEPROM block at +25°C and guarantees 40 years of data retention at +85°C. Endurance degrades with temperature, and retention is reduced above +85°C - confirming DS2460S+T&R's suitability for long-life deployments like utility meters and building access systems where field replacement is costly.

Is the DS2460S+T&R pin-compatible with other Maxim SHA coprocessors?

No, DS2460S+T&R is not pin-compatible with other Maxim SHA coprocessors such as DS28E01-100+ (1-Wire interface) or ATSHA204A (4-wire I²C with SHA-256). Its 8-pin SOIC package with AD0–AD2 address pins, NC, SDA, SCL, VCC, and GND is unique to this family - meaning DS2460S+T&R requires dedicated PCB layout and cannot serve as a drop-in replacement without hardware revision.