Analog Devices Inc./Maxim Integrated DS2704G+

Overview

DS2704G+ from Maxim Integrated (now Analog Devices) is a secure 1280-bit EEPROM with integrated SHA-1 authentication engine, designed for battery pack identification and cryptographic challenge-response in single-contact 1-Wire systems. It features five lockable 32-byte EEPROM pages, operates from 2.5V to 5.5V, and delivers 160-bit MAC responses in ≤30ms. It is deployed in smart battery packs for wireless handsets and portable computing devices.

For engineers reviewing the DS2704G+ datasheet, DS2704G+ pinout, DS2704G+ application, or DS2704G+ equivalent, key selection considerations include 1-Wire interface timing modes (Standard/Overdrive), secret key management commands (Clear/Lock/Compute Next Secret), EEPROM write endurance (50,000 cycles for data, 1,000 for secret), and TDFN-6 package compatibility with space-constrained battery management PCBs.

Technical Context

The DS2704G+ implements a FIPS-180-1/180-2 and ISO/IEC 10118-3 compliant SHA-1 engine that computes a 160-bit Message Authentication Code using a 64-bit on-chip secret, a 64-bit host-provided challenge, and fixed or ROM ID–augmented constants - with no secret ever transmitted over the bus. Its 1-Wire interface supports both Standard (16kbps) and Overdrive (143kbps) timing modes, each with distinct tSLOT, tRSTL, and tRDV specifications.

It operates in four deterministic power modes: standby (≤3μA), communication (5–75μA depending on timing mode), computation (75–500μA during SHA-1), and programming (400–750μA during EEPROM write). Memory access uses a linear 1280-bit address space organized into five 32-byte pages, with individual page write protection controlled via status register bitfield B0–B4.

Key Specifications

Pinout & Package

DS2704G+ is housed in a lead-free 3mm × 3mm TDFN-6 package with exposed thermal pad on bottom. Pin 1 = VDD, Pin 5 = VSS, Pin 6 = DQ (bidirectional 1-Wire I/O), Pins 2–4 = NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar secure EEPROM with authentication applications.

Compared with DS2704G+, DS2705G+ offers drop-in compatibility with added CRC capability, while MAX4802AETE+ provides higher memory density and AES-128 but requires I²C redesign and does not support 1-Wire topology - making DS2704G+ optimal for cost-sensitive, space-constrained single-wire battery authentication.

Availability

DS2704G+ is available at Aetrix Electronics and suitable for smart battery authentication, portable device calibration storage, and peripheral identity verification requiring stable component supply across consumer electronics production cycles.

Supply support for DS2704G+ 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

Analog Devices (via acquisition of Maxim Integrated) designs precision analog, mixed-signal, and secure ICs for industrial, automotive, and consumer applications - with deep heritage in battery management and 1-Wire technology.

The DS2704G+ belongs to Maxim's secure battery authentication product line, engineered specifically to prevent counterfeit battery use in mobile devices through hardware-enforced cryptographic identity and tamper-resistant memory.

FAQ

What is the primary function of the DS2704G+ in battery management systems?

The DS2704G+ serves as a secure identity and data storage device in battery packs, combining 1280-bit EEPROM with a FIPS-compliant SHA-1 engine. It enables cryptographic challenge-response authentication to verify OEM battery authenticity and stores calibrated cell parameters, manufacturing data, and usage history - all accessible via a single 1-Wire contact. Its design ensures the secret key remains internal and never traverses the bus.

Does the DS2704G+ require an external high-voltage programming source?

No, the DS2704G+ does not require external high-voltage programming. It integrates an on-chip charge pump that enables full in-circuit EEPROM programming using only the standard 2.5V–5.5V VDD supply. This eliminates the need for specialized high-voltage pulses during battery pack manufacturing - simplifying assembly and reducing test complexity compared to EPROM-based predecessors like the DS2502.

How does the DS2704G+ support backward compatibility with existing DS2502-based systems?

The DS2704G+ maintains functional command-level compatibility with the DS2502 for memory read operations: it accepts Read Memory (F0h) and Read Data/Generate CRC (C3h) commands and returns identical data formats for the lower 1024 bits (Pages 0–3). While its EEPROM architecture differs (rewritable vs. one-time-programmable), the DS2704G+ preserves DS2502's Net Address and ROM command structure - enabling firmware reuse with minimal host-side modifications.

What are the power consumption characteristics of the DS2704G+ across operating modes?

The DS2704G+ exhibits mode-dependent current draw: ≤3μA in standby (DQ = VDD), 5–25μA in Standard-mode communication, 25–75μA in Overdrive-mode communication, 75–500μA during SHA-1 computation (tSHA ≤30ms), and 400–750μA during EEPROM programming (tEEC = 10ms). These values - specified at -30°C to +85°C and VDD = 3.7V - ensure ultra-low quiescent drain in battery-powered applications while supporting rapid authentication cycles.

Can the secret key in the DS2704G+ be updated or rotated in the field?

Yes, the DS2704G+ supports field-updatable secret keys via Compute Next Secret commands (30h with ROM ID, 33h without). These commands execute SHA-1 on the current secret and challenge, then store a derived 64-bit portion of the MAC as the new secret - all within the device. The secret can be cleared (5Ah), locked (6Ah), or reprogrammed up to 1,000 times, enabling secure key rotation for long-life battery packs without physical replacement of the DS2704G+.