Microchip Technology AT97SC3205-H3M45-20

Overview

AT97SC3205-H3M45-20 from Microchip (acquired Atmel) is a TCG-compliant Trusted Platform Module (TPM) 1.2 security IC with integrated AVR RISC microprocessor, hardware RSA crypto engine, FIPS-140-2 certified RNG/AES/SHA/RSA engines, and 2066-byte NV user storage. It operates at 3.3V, supports SPI up to 45MHz, and targets PC motherboard and embedded system root-of-trust applications.

For engineers reviewing the AT97SC3205-H3M45-20 datasheet, AT97SC3205-H3M45-20 pinout, AT97SC3205-H3M45-20 application, or AT97SC3205-H3M45-20 equivalent, key selection criteria include TCG 1.2/TIS 1.3 compliance, SPI interface timing (24–33 MHz typical PC range), industrial temperature support (−40°C to +85°C), and QFN-32 package compatibility with secure boot and firmware integrity verification requirements.

Technical Context

The AT97SC3205-H3M45-20 implements a dedicated TPM 1.2 stack in firmware with hardware-accelerated asymmetric cryptography (RSA key generation and signing), a FIPS-140-2 validated pseudo-RNG for key derivation, and internal EEPROM for persistent RSA key storage. Its SPI interface uses active-low PIRQ#, SPI_CS#, and SPI_RST# with precise reset pulse width ≥2 μs.

Security architecture includes physical tamper detection via XTamper pin, hardware Physical Presence (PP/GPIO) signaling, GPIO Express-00 for NV index mapping, and dynamic internal memory management for RSA key caching-requiring no host intervention for TPM_FlushSpecific or TPM_LoadKey2 operations.

Key Specifications

Pinout & Package

AT97SC3205-H3M45-20 is packaged in a 32-pad Very Thin QFN (32M3) with 4.0 × 4.0 mm body, 0.4 mm pitch, and exposed GND center pad internally tied to ground. Pinout follows TCG-specified SPI-TIS layout with dedicated interrupt, reset, and physical presence signaling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TPM 1.2 security module applications.

Compared with SLB9665 TT 1.2 and NPCT750KB0GX, the AT97SC3205-H3M45-20 offers AVR-native firmware compatibility, tighter SPI timing margin at 45 MHz, and direct GPIO Express-00 mapping for simplified NV index control-making it optimal for cost-sensitive industrial PC designs prioritizing minimal host driver changes.

Availability

AT97SC3205-H3M45-20 is available at Aetrix Electronics and suitable for secure boot validation, firmware attestation, hardware physical presence enforcement, and platform recovery applications requiring stable component supply across industrial temperature ranges and long product lifecycles.

Supply support for AT97SC3205-H3M45-20 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 its secure MCU and TPM product lines. The company specializes in microcontrollers, analog, FPGA, and security solutions for industrial, automotive, and IoT markets.

The AT97SC3205-H3M45-20 belongs to Atmel's Trusted Platform Module family, designed specifically to deliver TCG 1.2-compliant hardware root-of-trust for PC motherboards, thin clients, and industrial gateways requiring FIPS-140-2 certified cryptographic acceleration.

FAQ

What TCG specifications does the AT97SC3205-H3M45-20 implement?

The AT97SC3205-H3M45-20 implements the Trusted Computing Group (TCG) Trusted Platform Module (TPM) Version 1.2 Specification and the PC Client-Specific TPM Interface Specification (TIS) Version 1.3. These standards define command sets, data structures, and interface behavior for interoperability with BIOS, UEFI, and operating system security stacks. The AT97SC3205-H3M45-20 is fully compliant with both, enabling drop-in integration into standard TPM-enabled platforms without firmware adaptation.

Does the AT97SC3205-H3M45-20 support FIPS-140-2 certification?

Yes, the AT97SC3205-H3M45-20 is FIPS-140-2 Level 2 certified as a complete module, covering its hardware random number generator (RNG), HMAC, AES, SHA, and RSA cryptographic engines. This certification validates the implementation's resistance to physical attack, logical bypass, and statistical weaknesses-making the AT97SC3205-H3M45-20 suitable for government, financial, and healthcare applications requiring validated cryptographic assurance.

What is the maximum SPI clock frequency supported by the AT97SC3205-H3M45-20?

The AT97SC3205-H3M45-20 supports SPI clock frequencies up to 45 MHz, though the typical operating range for PC platforms is specified as 24 MHz to 33 MHz. This headroom allows robust timing margin under voltage/temperature variation while maintaining compatibility with standard TIS 1.3 timing parameters. The AT97SC3205-H3M45-20's SPI interface remains fully functional across its entire rated industrial temperature range (−40°C to +85°C) at these speeds.

How is physical presence enforced on the AT97SC3205-H3M45-20?

Physical presence is enforced via the PP/GPIO pin on the AT97SC3205-H3M45-20, which serves as a hardware indicator for BIOS-initiated TPM configuration changes. When asserted high, it signals that a local operator has confirmed an action such as TPM ownership takeover or dictionary attack lockout reset. The AT97SC3205-H3M45-20 firmware blocks sensitive commands unless this pin is actively driven-preventing remote administrative escalation without physical access.

What package type and dimensions does the AT97SC3205-H3M45-20 use?

The AT97SC3205-H3M45-20 uses a 32-pad Very Thin Quad Flat No-Lead (VQFN) package designated 32M3: 4.0 mm × 4.0 mm × 0.90 mm body with 0.4 mm lead pitch. It features an exposed center pad internally connected to GND, which must be soldered for thermal dissipation and EMI suppression. This RoHS-compliant package matches JEDEC MO-220 outline and supports automated PCB assembly with standard reflow profiles.