Microchip Technology AT97SC3205T-H3M4C-00

Overview

AT97SC3205T-H3M4C-00 from Microchip Technology (formerly Atmel) is a TCG-compliant Trusted Platform Module (TPM) 1.2 security IC implementing hardware-based asymmetric cryptography, FIPS-140-2 certified RNG/AES/SHA/RSA engines, and 2066-byte NV user storage. It integrates an AVR® RISC microprocessor and operates at 3.3V via I²C interface in embedded platform authentication and secure boot applications.

For engineers reviewing the AT97SC3205T-H3M4C-00 datasheet, AT97SC3205T-H3M4C-00 pinout, AT97SC3205T-H3M4C-00 application, or AT97SC3205T-H3M4C-00 equivalent, key selection factors include TPM 1.2 compliance, I²C timing (400 kHz Fast Mode), industrial temperature range (–40°C to +85°C), QFN-32 package footprint, and hardware-enforced cryptographic isolation for root-of-trust implementation.

Technical Context

The AT97SC3205T-H3M4C-00 implements the full TCG TPM 1.2 specification stack in silicon, including command parsing, session management, and authorization logic. Its internal AVR CPU executes firmware that enforces strict state machine transitions and physical tamper detection via dedicated circuitry.

Cryptographic operations are offloaded to dedicated hardware engines: RSA key generation and signing, SHA-1 hashing, HMAC-SHA1 authentication, AES-128 encryption, and a FIPS-140-2 validated PRNG. All keys reside exclusively in on-chip EEPROM with write-protection enforced by TPM ownership hierarchy and locality checks.

Key Specifications

Pinout & Package

AT97SC3205T-H3M4C-00 is supplied in a 32-pad Very Thin QFN (32M3) package: 4.0 × 4.0 × 0.90 mm body, 0.40 mm pitch, exposed thermal pad tied internally to GND. Pinout optimized for minimal trace length on SM_DAT/SM_CLK lines and separation of analog (RNG) and digital domains.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TPM security module applications.

Compared with ST33TPHF2XSS and SLB9670, the AT97SC3205T-H3M4C-00 offers lower system integration complexity for TPM 1.2 deployments, smaller QFN-32 footprint (4.0 × 4.0 mm), and verified interoperability with legacy BIOS/UEFI implementations - making it ideal for cost-sensitive, long-lifecycle industrial platforms where TPM 2.0 migration is not mandated.

Availability

AT97SC3205T-H3M4C-00 is available at Aetrix Electronics and suitable for server boot integrity, industrial PLC secure firmware update, and network equipment device identity applications requiring stable component supply and long-term industrial temperature support.

Supply support for AT97SC3205T-H3M4C-00 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology acquired Atmel in 2016 and maintains full product support, documentation, and qualification for legacy Atmel security ICs including the AT97SC3205T series.

The AT97SC3205T product line was designed specifically for embedded systems requiring hardware-rooted trust anchors compliant with TCG TPM 1.2 - targeting industrial control, networking infrastructure, and computing platforms where firmware integrity and cryptographic key protection are mission-critical.

FAQ

What is the operating voltage range for the AT97SC3205T-H3M4C-00?

The AT97SC3205T-H3M4C-00 operates at a nominal supply voltage of 3.3 V with a tolerance of ±10%, meaning it functions reliably between 2.97 V and 3.63 V. This voltage must be tightly regulated and decoupled using specified capacitor values and placement distances to ensure stable cryptographic engine operation and prevent timing-related faults during RSA or AES computations. The AT97SC3205T-H3M4C-00 does not support dual-supply or wide-input voltage operation.

Does the AT97SC3205T-H3M4C-00 support TPM 2.0 functionality?

No, the AT97SC3205T-H3M4C-00 implements only the Trusted Computing Group TPM 1.2 specification and does not support TPM 2.0 features such as SHA-256, ECC algorithms, or hierarchical key structures. Its firmware, command set, and cryptographic engine are fixed to TPM 1.2 compliance as verified in its FIPS-140-2 certification. For TPM 2.0 requirements, alternative parts like ST33TPHF2XSS or SLB9670 must be selected. The AT97SC3205T-H3M4C-00 remains fully functional within TPM 1.2 ecosystems.

What package type is used for the AT97SC3205T-H3M4C-00?

The AT97SC3205T-H3M4C-00 is packaged in a 32-pad Very Thin QFN (32M3) with 4.0 × 4.0 × 0.90 mm body dimensions and 0.40 mm pitch. The exposed thermal pad is internally connected to GND, requiring soldering to the PCB ground plane for thermal dissipation and noise reduction. This package differs from the optional 28-pin TSSOP variant and is explicitly designated by the "H3M4C" suffix in the part number.

How is cryptographic key storage implemented in the AT97SC3205T-H3M4C-00?

The AT97SC3205T-H3M4C-00 uses on-chip EEPROM to store RSA private keys and other sensitive material, with hardware-enforced write protection governed by TPM ownership hierarchy and locality checks. Keys never leave the die and cannot be read out in plaintext; all cryptographic operations occur internally. The AT97SC3205T-H3M4C-00 also provides 2066 bytes of additional NV user storage accessible only via authenticated TPM commands, separate from key storage partitions.

What I²C timing modes does the AT97SC3205T-H3M4C-00 support?

The AT97SC3205T-H3M4C-00 supports both Standard Mode (100 kHz) and Fast Mode (400 kHz) I²C communication. Stable operation at 400 kHz requires precise pull-up resistor values: 800 Ω on SM_DAT and 1.5 kΩ on SM_CLK, along with a 50% duty-cycle clock signal. The AT97SC3205T-H3M4C-00 does not support Fast Mode Plus (1 MHz) or High-Speed Mode, and its I²C interface lacks clock stretching capability.