Microchip Technology AT97SC3205T-H3M46-10

Overview

AT97SC3205T-H3M46-10 from Microchip (formerly Atmel) is a TCG-compliant Trusted Platform Module (TPM) 1.2 security IC integrating an AVR® RISC microprocessor, hardware asymmetric crypto engine, FIPS-140-2 certified RNG/AES/SHA/RSA engines, and 2066-byte NV user storage. It operates at 3.3V with I²C interface (400 kHz Fast Mode) and targets secure boot, platform authentication, and key management in embedded computing systems.

For engineers reviewing the AT97SC3205T-H3M46-10 datasheet, AT97SC3205T-H3M46-10 pinout, AT97SC3205T-H3M46-10 application, or AT97SC3205T-H3M46-10 equivalent, this page delivers verified electrical specs, validated I²C timing constraints, confirmed GPIO-Express and Physical Presence pin functions, package-specific pin mapping for 32-pad QFN, and real-world TPM deployment considerations including deep-sleep recovery via TWI_Wakeup# and PIRQ# interrupt signaling.

Technical Context

The AT97SC3205T-H3M46-10 implements the full TCG TPM 1.2 specification stack in silicon, with dedicated hardware acceleration for RSA key generation, HMAC-SHA-1 signing, and AES-128 encryption. Its internal EEPROM stores persistent RSA keys, while the FIPS-140-2 certified RNG feeds cryptographic primitives and protocol randomness requirements.

It uses a single-chip architecture combining AVR CPU core, SRAM, crypto engine, and physical security circuitry - eliminating external memory dependencies. The I²C interface supports both Standard (100 kHz) and Fast (400 kHz) modes with strict pull-up resistor guidance (800 Ω on SM_DAT, 1.5 kΩ on SM_CLK) and 50% duty-cycle clock optimization for stable communication.

Key Specifications

Pinout & Package

AT97SC3205T-H3M46-10 is supplied in a 32-pad Very Thin QFN (32M3) package with 0.40 mm pitch and 4.0 × 4.0 mm body. The exposed center pad is internally connected to GND and may be left floating or soldered to PCB ground plane for thermal and EMI performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT97SC3205T-H3M46-10, SLB9665TT2.0 shifts interface dependency to SPI and removes GPIO-Express functionality, while NPCT750A trades FIPS-140-2 module certification for integrated supervision - making AT97SC3205T-H3M46-10 optimal for I²C-based designs requiring auditable, hardware-enforced key lifecycle control.

Availability

AT97SC3205T-H3M46-10 is available at Aetrix Electronics and suitable for secure boot authentication, platform integrity attestation, and hardware-bound key storage requiring stable component supply across industrial and embedded computing programs.

Supply support for AT97SC3205T-H3M46-10 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 belongs to Atmel's Trusted Platform Module product line, designed specifically to deliver certified, single-chip TPM 1.2 functionality for embedded systems needing hardware-rooted trust without external crypto co-processors.

FAQ

What is the primary interface type and speed supported by the AT97SC3205T-H3M46-10?

The AT97SC3205T-H3M46-10 uses an I²C interface supporting both Standard Mode (100 kHz) and Fast Mode (400 kHz). For reliable 400 kHz operation, the datasheet specifies 800 Ω pull-up on SM_DAT and 1.5 kΩ on SM_CLK, with strong recommendation for a 50% duty-cycle clock waveform to maximize signal integrity and reduce communication errors in noisy environments. The AT97SC3205T-H3M46-10 does not support SPI or UART interfaces.

Does the AT97SC3205T-H3M46-10 include FIPS-140-2 certification, and what modules are covered?

Yes, the AT97SC3205T-H3M46-10 is FIPS-140-2 certified as a complete module, covering its hardware random number generator (RNG), HMAC, AES-128, SHA-1, and RSA cryptographic engines. This certification validates the implementation against NIST standards for cryptographic module security and is documented in the official FIPS certificate issued to Atmel's TPM solution. The AT97SC3205T-H3M46-10 certification applies to the full device, not just individual blocks.

How is physical presence enforced on the AT97SC3205T-H3M46-10, and why is it required?

The AT97SC3205T-H3M46-10 enforces physical presence through the dedicated PP/GPIO pin, which must be driven high to authorize privileged operations such as TPM_Clear, Owner establishment, or dictionary attack lockout reset. This hardware gating prevents remote attackers from executing destructive or privilege-escalating commands without local physical access. The AT97SC3205T-H3M46-10 design mandates this signal for TCG-compliant TPM 1.2 behavior and cannot bypass it via firmware or configuration.

What NV storage capacity and addressing method does the AT97SC3205T-H3M46-10 provide for user data?

The AT97SC3205T-H3M46-10 provides 2066 bytes of non-volatile user storage accessible via TCG-defined NV indices. One dedicated index, TPM_NV_INDEX_GPIO_00, maps directly to the GPIO-Express-00 pin for persistent state retention. User data is written and read using standard TPM_NV_Write and TPM_NV_Read commands, with access controlled by authorization policies. The AT97SC3205T-H3M46-10 does not expose this storage as a generic EEPROM block - all access is mediated by the TPM command interface.

Can the AT97SC3205T-H3M46-10 enter low-power states, and how is wake-up managed?

Yes, the AT97SC3205T-H3M46-10 supports deep-sleep mode via the TPM_DeepSleep command, reducing power consumption during idle periods. Recovery requires pulsing two dedicated pins - TWI_Wakeup# (pin 7) and TWI_Wakeup# (pin 22) - both low simultaneously. This dual-signal requirement prevents accidental wake-up and ensures deterministic resumption. The AT97SC3205T-H3M46-10 does not support automatic wake-up on I²C traffic or timer events - explicit hardware signaling is mandatory.