Analog Devices Inc./Maxim Integrated DS28E25Q+T

The DS28E25 uses an on-chip SHA-256 engine to compute message authentication codes from a protected secret, host challenge, user-memory data, and its factory-programmed 64-bit ROM ID. Slave-to-host authentication validates an attached device; host-to-slave authentication can protect user EEPROM against an unauthenticated host. It communicates over a single-contact 1-Wire bus.

LCDChip registers 6-WDFN Exposed Pad. Analog Devices' ordering table identifies DS28E25Q+T as a six-pin TDFN-EP in tape and reel, package code T633+2. The six-pin TSOC P+T variant has a different footprint and pin assignment.

Layout checks

• Verify the controlled TDFN-EP outline and pin-one mark.
• Provide the specified 1-Wire pullup and recovery timing.
• Confirm the bus capacitance budget with every attached node.

The expected local JPG is absent and its production URL returns HTTP 404; keep this draft unpublished until the correct asset is restored and inspected.

For the six-pin TDFN-EP, pin 3 is GND, pin 2 is the open-drain 1-Wire IO requiring an external pullup, and pins 1, 4, 5 and 6 are not connected. Connect the exposed pad evenly to the board ground plane as directed by the manufacturer. Do not use the P+T TSOC pinout for this Q+T part.

System pullup values and timing must be selected from the manufacturer electrical tables for actual network loading.

Other authenticators may differ in cryptographic algorithm, secret provisioning, EEPROM map, irreversible protections, 1-Wire commands, and footprint. Do not assume interchangeability solely from the 1-Wire interface or six-pin outline. No unverified internal alternative is linked.

Analog Devices' DS28E25 DeepCover Secure Authenticator with 1-Wire SHA-256 and 4Kb User EEPROM, abridged data sheet Rev. 4, supplies the public feature list, electrical limits, TDFN-EP pin description, and ordering table. Request the controlled full data sheet for detailed commands.

Verify marking, traceability, TDFN-EP dimensions and ROM ID. Test challenge generation, MAC validation, host-to-device authorization and every irreversible protection setting. Protect the secret during provisioning and confirm failure handling on the actual bus.

Confirm production documentation, TDFN-EP land pattern, 1-Wire electrical timing, irreversible memory controls, and secret-management processes before use. Restore and inspect the production package JPG before formal publication.