Analog Devices Inc./Maxim Integrated DS28E22P+T

The DS28E22 uses a hardware SHA-256 engine and a protected secret to generate message authentication codes based on a host challenge, memory data and the device's factory-programmed 64-bit ROM ID. The host can authenticate the attached device, while authenticated host operations can protect writes to user memory. Communication uses a single-contact 1-Wire bus.

LCDChip registers 6-SMD, J-Lead. Analog Devices identifies the exact DS28E22P+T ordering code as a six-lead TSOC in tape-and-reel supply, package code D6+1. The Q+T variant instead uses a six-pin exposed-pad TDFN and requires a different land pattern.

Layout checks

• Check the manufacturer's TSOC outline and pin-one orientation.
• Provide a 1-Wire pullup suited to bus loading and timing.
• Do not substitute the TDFN-EP footprint or pin mapping.

The expected local JPG is absent and the production JPG URL returns HTTP 404. Keep this draft unpublished until the correct image is restored and checked.

In the six-lead TSOC, pin 1 is GND; pin 2 is the open-drain 1-Wire IO and requires an external pullup resistor; pins 3, 4, 5 and 6 are not connected. The TDFN-EP package has a different GND location and an exposed pad, so its pinout must not be used for this P+T order code.

The resistance range is conditional on the manufacturer's stated single-device recovery-time assumptions; size the network for actual loading.

Other 1-Wire authenticators may use different EEPROM sizes, secrets, commands, protection behavior, pin assignments and footprints. A matching bus or package description does not establish drop-in compatibility. Validate protocol, provisioning, electrical conditions and order-code packaging before any substitution. No unverified internal alternative is linked.

Analog Devices' DS28E22 DeepCover Secure Authenticator with 1-Wire SHA-256 and 2Kb User EEPROM, abridged data sheet Rev. 3, supplies the public features, TSOC pin description, electrical characteristics and exact ordering table. Request the controlled full document for detailed commands.

Check device markings, traceability, TSOC dimensions and the unique ROM ID. Test the authentication exchange, protected memory behavior and irreversible configuration on the actual host bus. Safeguard the secret throughout provisioning.

Confirm the controlled TSOC footprint, 1-Wire timing, network pullup, memory protection and secret-management procedure against the latest manufacturer documents. Restore and inspect the production package JPG before formal publication.