Microchip Technology ATECC108-SSHDA-T

The ATECC108 stores cryptographic keys and performs authentication operations in hardware so a host need not expose secret material during every exchange. It supports ECDSA, SHA-256, HMAC-related operations, a hardware random-number generator, and host or client authentication roles. The SSHDA-T ordering option uses I²C in an 8-lead SOIC supplied in tape-and-reel form.

The exact SSHDA-T order code is the I²C, tape-and-reel, 8-lead SOIC option. The manufacturer 8S1 drawing identifies a 0.150-inch wide-body plastic gull-wing package, with 3.81–3.99 mm body width and 1.27 mm lead pitch. The site's existing normalized 8-SOIC registration corresponds to its 0.154-inch-width package category.

Layout checks

• Match the 8S1 land pattern and pin-1 mark to the mechanical drawing.
• Place VCC decoupling close to the device and provide I²C pull-ups appropriate to the host bus.
• Keep the four NC pins unconnected unless the manufacturer's full design instructions require otherwise.

The existing package registry entry and local JPG were checked. This illustration is not a dimensional drawing.

Manufacturer summary datasheet, top-view 8-lead SOIC with I²C interface:

Check orientation against the package top view before PCB release.

The publicly available document is a summary; obtain the full controlled datasheet and configuration guidance for firmware and production provisioning.

Microchip identifies ATECC108A as the successor to ATECC108, but a migration still requires review of command behavior, configuration zones, provisioning, certificates, package, interface selection, and key policy. The SSHCZ order code is a single-wire variant, not the I²C interface specified here. No internal alternative is linked without a verified exact product record.

The manufacturer ATECC108 Summary Datasheet, Atmel-8873BS, provides the public feature list, package drawing, pin configuration, and ordering table. It labels the original ATECC108 not recommended for new designs and names ATECC108A as the replacement family. The complete ATECC108 datasheet is controlled, so design-specific command and configuration details need the appropriate manufacturer documentation.

Verify the full SSHDA-T order code, lot traceability, SOIC marking, and intended I²C personality. Confirm serial identity, key configuration, access permissions, and provisioning status using authorized manufacturer procedures before deployment.

Authentication strength depends on secure provisioning and host-side protocol design, not the IC alone. Obtain the complete controlled device documentation for command timing, configuration locking, and key policy. Respect the documented voltage, I²C, layout, and package limits; plan a qualified successor for new designs.