AT97SC3205T-G3M4620B

Overview

The AT97SC3205T-G3M4620B is a Trusted Platform Module (TPM) compliant with the TCG TPM Version 1.2 specification. It integrates an Atmel AVR RISC microprocessor, hardware asymmetric crypto engine, and internal EEPROM for RSA key storage. The device supports I2C communication at 400kHz Fast Mode or 100kHz Standard Mode. It features FIPS-140-2 certification for its RNG, HMAC, AES, SHA, and RSA engines. Operating on a 3.3V supply, it provides 2066 bytes of NV user-defined data storage and is available in 28-lead Thin TSSOP or 32-pad QFN packages.

Feature Summary

• Compliant with TCG TPM Version 1.2 and TCG PC Client-Specific TPM Interface Specification (TIS) Version 1.3
• Hardware Asymmetric Crypto Engine with FIPS-140-2 certified RNG, HMAC, AES, SHA, and RSA
• Atmel AVR RISC Microprocessor with internal EEPROM for RSA keys and 2066 bytes NV storage
• I2C interface supporting 400kHz Fast Mode and 100kHz Standard Mode

Applications

• Embedded systems requiring hardware-based security authentication
• PC client platforms needing trusted platform module implementation
• Secure boot and identity management in embedded devices

Procurement Notes

Verify package type availability as the component is offered in both 28-lead Thin TSSOP and 32-pad QFN configurations. Confirm operational temperature range requirements against Commercial (0°C to 70°C) and Industrial (-40°C to 85°C) options. Ensure proper decoupling capacitors are placed close to VCC pins to maintain signal integrity at high I2C speeds.

Selection Notes

Select the appropriate package based on board space constraints: 28X1 for TSSOP or 32M3 for QFN. Verify that the host system can support the required I2C pull-up values (800Ω for SM_DAT, 1.5KΩ for SM_CLK) for stable 400kHz operation. Consider GPIO pin assignments for physical presence detection and low-power sleep recovery mechanisms.

Part Context

This component belongs to the AT97SC3205T family of security ICs manufactured by Microchip Technology (formerly Atmel). It serves as a single-chip turnkey solution for implementing TPM functionality without requiring external cryptographic components. The device replaces discrete security solutions by integrating all necessary processing and storage elements.

Replacement Considerations

Check for updated versions within the AT97SC3205T series that may offer different package options or extended temperature ranges. Verify compatibility with existing firmware implementations when substituting between TSSOP and QFN variants due to pin configuration differences.

FAQ

What are the recommended pull-up resistor values for I2C communication?

For reliable 400kHz operation, use 800Ω on the SM_DAT line and 1.5KΩ on the SM_CLK line.

How should unused GPIO pins be handled?

Unused GPIO pins should be tied high or low according to their internal pull-up/pull-down configurations. Specifically, GPIO-Express-00 has an internal pull-up and should be left floating if unused, while PP/GPIO has an internal pull-down.

What is the minimum reset pulse width required?

The LRESET# signal requires a minimum pulse width of 2μs to properly reset the internal state of the TPM.