Analog Devices Inc./Maxim Integrated DS28E40ATB/VY+T

The DS28E40 supports bidirectional authentication over a single-contact 1-Wire bus. Its hardware provides ECC-P256 public-key operations, SHA-256 secret-key operations, a true-random-number generator, a factory-programmed 64-bit ROM ID and a command-controlled GPIO. Six kilobits of secured OTP capacity are divided between user storage and keys or secrets.

LCDChip registers 10-WFDFN Exposed Pad. The manufacturer's exact ordering row maps DS28E40ATB/VY+T to 10-pin TDFN package code T1033Y+2, measuring 3 mm × 3 mm with side-wettable leads. The exposed pad must be soldered evenly to the ground plane; use the controlled package drawing and land pattern for PCB design.

Layout checks

• Verify T1033Y+2 footprint and pin-one orientation.
• Connect the exposed pad to the ground plane.
• Provide the CEXT capacitor and the specified 1-Wire pullup network.

The expected package JPG is absent locally and returns HTTP 404 on the production site. This detail remains unpublished until the correct image is restored and inspected.

The manufacturer's 10-pin TDFN pin table assigns pin 2 to GPIO, pin 4 to 1-Wire IO, pin 5 to GND and pin 10 to CEXT, the external-capacitor input. Pins 1, 3 and 6 through 9 are DNC and must not be connected. Solder the exposed pad evenly to the ground plane.

Do not route the DNC pins as signal connections.

Electrical limits and system requirements are stated with their respective manufacturer conditions; validate the complete 1-Wire power and timing network in the end equipment.

Another secure authenticator is not a drop-in substitute merely because it implements ECC-P256 or SHA-256. Compare command sets, key and certificate provisioning, OTP map, authenticated GPIO policy, 1-Wire supply behavior, temperature rating and exact TDFN footprint. The DS28E40G/V+T ordering variant uses a different TDFN package code and footprint. No unverified internal alternative is linked.

Analog Devices publishes the Maxim Integrated DS28E40 DeepCover Automotive 1-Wire Authenticator data sheet, Rev. 1. Its exact ordering row identifies the ATB/VY+T suffix and T1033Y+2 package; the pin and electrical tables define integration requirements. Obtain the separate controlled Security User Guide for command-level implementation.

Inspect device marking, supply traceability, side-wettable lead geometry and the exact TDFN package. Verify the factory ROM ID, cryptographic challenge-response behavior and host certificate policy using authorized test credentials. Test GPIO, exposed-pad grounding and 1-Wire supply margins over the intended automotive environment.

Use controlled manufacturer documentation for security commands and irreversible provisioning. Confirm CEXT, strong-pullup capability, DNC handling, GPIO policy, side-wettable footprint and AEC-Q100 requirements for the exact order code. Restore and verify the package JPG before formal publication.