Microchip Technology AT97SC3205T-H3M4600B

Overview

AT97SC3205T-H3M4600B from 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 industrial systems.

For engineers reviewing the AT97SC3205T-H3M4600B datasheet, AT97SC3205T-H3M4600B pinout, AT97SC3205T-H3M4600B application, or AT97SC3205T-H3M4600B equivalent, this page delivers verified electrical specs, validated I²C timing constraints, confirmed package mapping to 32-pad QFN (32M3), and real-world TPM deployment guidance for OEM firmware integration.

Technical Context

The AT97SC3205T-H3M4600B implements the full TCG TPM 1.2 specification stack in silicon, including command parsing, cryptographic acceleration, and secure non-volatile key storage. Its AVR CPU executes firmware that enforces strict physical and logical security boundaries between host I²C transactions and internal RSA key operations.

It supports two power states-active and low-power sleep-with TWI_Wakeup# requiring dual-pin active-low assertion for recovery. The I²C interface mandates specific pull-up values (800 Ω on SM_DAT, 1.5 kΩ on SM_CLK) for stable 400 kHz operation and requires 50% duty cycle clocking for optimal signal integrity.

Key Specifications

Pinout & Package

AT97SC3205T-H3M4600B is packaged in a 32-pad Very Thin QFN (32M3) with 0.40 mm pitch and an exposed center thermal pad internally connected to GND. This package enables compact PCB layout and efficient heat dissipation in space-constrained embedded modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ST33TPHF2Xx and SLB9670, the AT97SC3205T-H3M4600B provides drop-in TPM 1.2 compliance with minimal host integration overhead, I²C-native design, and proven FIPS-140-2 Level 2 certification-ideal for cost-sensitive industrial platforms needing field-proven security without architectural overhaul.

Availability

AT97SC3205T-H3M4600B is available at Aetrix Electronics and suitable for server platform authentication, industrial control system integrity, and medical device data sealing requiring stable component supply across long-lifecycle embedded programs.

Supply support for AT97SC3205T-H3M4600B 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

Atmel Corporation, now part of Microchip Technology, designed secure microcontrollers and TPM solutions for embedded trust and cryptographic acceleration.

The AT97SC3205T product line delivers integrated, FIPS-certified TPM 1.2 modules targeting industrial, medical, and network infrastructure applications requiring hardware-rooted security without external crypto co-processors.

FAQ

What is the primary security certification level of the AT97SC3205T-H3M4600B?

The AT97SC3205T-H3M4600B is FIPS-140-2 Level 2 certified, covering its hardware random number generator (RNG), HMAC, AES, SHA, and RSA cryptographic engines. This certification validates the module's resistance to physical tampering and ensures cryptographic operations meet U.S. government standards for sensitive but unclassified data protection. The AT97SC3205T-H3M4600B achieves this through secure hardware design, internal EEPROM key storage, and tamper-evident layout-making it suitable for regulated industrial and medical deployments where cryptographic assurance is mandatory.

Does the AT97SC3205T-H3M4600B support both commercial and industrial temperature ranges?

Yes, the AT97SC3205T-H3M4600B is qualified for industrial operation from –40°C to +85°C, as confirmed in the ordering information section of its summary datasheet. While the base part number AT97SC3205T supports both commercial (0°C to 70°C) and industrial ranges, the specific variant AT97SC3205T-H3M4600B corresponds to the 32-pad QFN (32M3) package in the industrial temperature grade. This makes the AT97SC3205T-H3M4600B appropriate for harsh-environment applications such as factory automation controllers and outdoor network infrastructure where thermal stability is critical.

How does the AT97SC3205T-H3M4600B handle low-power states and wake-up recovery?

The AT97SC3205T-H3M4600B automatically enters low-power sleep mode during idle periods to reduce system energy consumption. Recovery requires asserting TWI_Wakeup# active-low on two dedicated pins-pin 7 and pin 22-simultaneously. This dual-pin requirement prevents spurious wake events and enhances reliability in electrically noisy industrial settings. The AT97SC3205T-H3M4600B does not support single-pin wake-up; failure to pulse both pins will leave the device in sleep state, ensuring deterministic power management behavior aligned with TCG-defined deep-sleep semantics.

What are the exact I²C timing and pull-up requirements for reliable 400 kHz operation of the AT97SC3205T-H3M4600B?

For stable 400 kHz Fast Mode I²C operation, the AT97SC3205T-H3M4600B requires an 800 Ω pull-up resistor on SM_DAT and a 1.5 kΩ pull-up on SM_CLK. Additionally, the SM_CLK signal must maintain a 50% duty cycle-deviations degrade communication reliability, especially at maximum speed. These values are empirically validated in Atmel's characterization; using higher resistance values or asymmetric clock waveforms may cause ACK timeouts or bus lockup. The AT97SC3205T-H3M4600B does not auto-negotiate speed-host firmware must configure timing registers accordingly.

Can the AT97SC3205T-H3M4600B be used as a direct replacement for other TPM 1.2 modules like the Infineon SLB9635?

No, the AT97SC3205T-H3M4600B is not a pin-compatible or drop-in replacement for the Infineon SLB9635 due to differences in pin count (32 vs. 32 but distinct pin mapping), I²C timing sensitivity, and GPIO assignment (e.g., PP/GPIO and TWI_Wakeup# implementation). While both comply with TPM 1.2, the AT97SC3205T-H3M4600B uses a unique pinout with dedicated dual-wake pins and specific pull-up requirements. Replacing SLB9635 with AT97SC3205T-H3M4600B requires PCB layout revision, firmware adaptation for GPIO handling, and validation of I²C signal integrity-making it a design-level migration, not a board-level swap.