Microchip Technology ATSHA204-SH-CZ-T

The ATSHA204 combines secure key storage with SHA-256 MAC and HMAC operations to authenticate accessories, firmware or other system elements. Its EEPROM can hold keys and protected application data. The SH-CZ-T variant uses the device's single-wire protocol through SDA, not the I2C interface of the SH-DA ordering options.

The official ordering table lists ATSHA204-SH-CZ-T as an 8-lead SOIC shipped on tape and reel. LCDChip's registered package name is 8-SOIC. Use Microchip's controlled package drawing and top-view pin diagram to finalize the footprint and assembly orientation.

Layout checks

• Connect the single-wire host signal to SDA, pin 5.
• Leave pins 1–3 and 7 unconnected.
• For single-wire sleep-current performance, hold SCL low or leave it unconnected as directed in the data sheet.

The image is a generic package aid rather than a device-specific pin map.

The manufacturer top-view 8-lead SOIC drawing assigns the following terminals. In the CZ single-wire mode, SCL is not used for communication.

Confirm pull-up and voltage-domain guidance in the single-wire wiring section before release.

Use the manufacturer's electrical tables for detailed limits, timing and measurement conditions.

Microchip identifies the original ATSHA204 as not recommended for new designs and names ATSHA204A as its successor. A migration still requires validation of the exact ordering code, interface configuration, provisioning, key and data layout, firmware commands and package. The SH-DA I2C option is not an unconditional replacement for this SH-CZ single-wire option. No unverified internal product link is asserted.

The original ATSHA204 was introduced by Atmel and is documented by Microchip Technology. The manufacturer data sheet Atmel-8740H lists ATSHA204-SH-CZ-T exactly and marks the family not recommended for new designs, with ATSHA204A named as the replacement family.

Verify the complete ordering code and source traceability, then check the programmed configuration through a controlled authentication test. The data sheet says the exact part number is not printed on the package; the lot marking alone is unsuitable as an incoming identity check.

Use Microchip's latest controlled data sheet, errata and package drawing for final schematic, firmware, security and PCB approval. Observe the published I/O voltage-limit erratum and single-wire pull-up guidance. The original ATSHA204 is not recommended for new designs; evaluate the manufacturer's successor for new platforms.