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Home > Products > Integrated Circuits (ICs) > Embedded > Application Specific Microcontrollers

Microchip Technology AT97SC3205T-U3A1C-20

Name: AT97SC3205T-U3A1C-20
Brand: Microchip Technology
SKU: AT97SC3205T-U3A1C-20
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AT97SC3205T-U3A1C-20

Manufacturer:: Microchip Technology

Category:: Application Specific Microcontrollers

Package:: 28-TSSOP (0.173", 4.40mm Width)

Datasheet:: AT97SC3205T-U3A1C-20.pdf

Description:: FF IND I2C TPM 4.4MM TSSOP SEK

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Product details

Overview

AT97SC3205T-U3A1C-20 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 (400kHz Fast Mode) and targets secure boot, platform authentication, and key management in embedded computing systems.

For engineers reviewing the AT97SC3205T-U3A1C-20 datasheet, AT97SC3205T-U3A1C-20 pinout, AT97SC3205T-U3A1C-20 application, or AT97SC3205T-U3A1C-20 equivalent, this page delivers verified electrical specs, validated I²C timing constraints, confirmed GPIO-Express and physical presence pin functions, and real-world low-power sleep recovery behavior per Atmel-8883AS-TPM-AT97SC3205T-Datasheet-Summary_022014.

Technical Context

The AT97SC3205T-U3A1C-20 implements the full TCG TPM 1.2 specification using on-die AVR CPU execution, dedicated hardware crypto accelerators for RSA key generation and HMAC operations, and internal EEPROM for persistent RSA key storage. Its I²C interface supports both Standard (100kHz) and Fast (400kHz) modes with strict pull-up resistor requirements (800Ω on SM_DAT, 1.5kΩ on SM_CLK) and 50% duty-cycle sensitivity on SM_CLK for stable communication.

Security architecture includes FIPS-140-2 certification covering RNG, AES, SHA, and RSA engines; tamper-resistant physical layout; and hardware-enforced isolation between crypto operations and firmware execution. The device enters automatic low-power sleep when idle and recovers only upon dual active-low assertion of TWI_Wakeup# pins (TSSOP pin 7 & 22), requiring precise external sequencing.

Key Specifications

Parameter	Value and Actual Design Meaning
TCG Compliance	Full TPM 1.2 specification implementation - enables standardized platform integrity attestation and sealed storage.
I²C Interface Speed	400kHz Fast Mode / 100kHz Standard Mode - requires 800Ω pull-up on SM_DAT and 1.5kΩ on SM_CLK for reliable high-speed operation.
Supply Voltage	3.3V ±5% - mandates tight decoupling: 2200–4700pF caps <5mm from each VCC-GND pair plus 0.1μF cap <10mm at VCC node junction.
NV User Storage	2066 bytes - allocated for customer-defined data indexed via TPM_NV_INDEX_GPIO_00 and other NV indices.
Crypto Engines	FIPS-140-2 certified RNG, HMAC, AES, SHA, RSA - provides NIST-validated primitives for key derivation, digital signatures, and secure hashing.
Operating Temperature	-40°C to +85°C industrial range - validated for deployment in extended-temperature embedded control and networking equipment.
Package Options	28-pin Thin TSSOP (4.4×9.7mm, 0.65mm pitch) or 32-pad QFN (4.0×4.0mm, 0.40mm pitch) - both RoHS-compliant and lead-free.

Pinout & Package

AT97SC3205T-U3A1C-20 is offered in two RoHS-compliant packages: 28-pin Thin TSSOP (4.40mm × 9.70mm body, 0.65mm pitch) and 32-pad QFN (4.00mm × 4.00mm body, 0.40mm pitch). Both packages feature exposed thermal pads tied internally to GND (QFN center pad) and include NC pins configurable as GND/VCC/floating per design needs.

Pin/Terminal	Circuit Role	Design Meaning
VCC	Power Supply Input	3.3V main supply - requires localized decoupling (2200–4700pF <5mm to adjacent GND) and system-level 0.1μF bypass (<10mm at VCC node junction).
LRESET#	Active-Low Reset	Resets internal TPM state; minimum pulse width 2μs; must remain asserted until VCC stabilizes at power-up.
SM_DAT / SM_CLK	I²C Data/Clock	Bi-directional I²C interface - SM_DAT requires 800Ω pull-up, SM_CLK requires 1.5kΩ pull-up for 400kHz operation; SM_CLK duty cycle should be ~50%.
PP/GPIO	Physical Presence Indicator	Hardware-based physical presence signal (active-high); also configurable as GPIO with internal pull-down; must float if unused.
GPIO-Express-00	Pre-mapped NV GPIO	Directly assigned to TPM_NV_INDEX_GPIO_00; internal pull-up enabled; serves as XOR chain output during I/O test mode.
TWI_Wakeup# (pins 7 & 22)	Low-Power Recovery	Both pins must be pulsed active-low simultaneously to exit deep sleep - no single-pin wake capability; pin 22 must be tied to GND/VCC.

Key Features

Feature	Design Value
Single-chip TPM 1.2 solution	Integrates AVR CPU, crypto engines, RNG, EEPROM, and I²C interface in one die - eliminates multi-chip security subsystem design complexity.
FIPS-140-2 certified crypto suite	Certification covers RNG, HMAC, AES, SHA, and RSA engines - satisfies regulatory requirements for government and financial sector deployments.
Hardware asymmetric crypto acceleration	Dedicated RSA engine enables fast key generation and signature verification without CPU overhead - critical for secure boot latency budgets.
2066-byte NV user storage	Customer-accessible non-volatile space mapped to standard TPM NV indices - supports firmware update signatures, device-specific keys, and audit logs.
Automatic low-power sleep	Enters sleep autonomously during I²C idle periods - reduces system power by eliminating need for software-controlled power management states.

Applications

Secure Boot Authentication	Platform Integrity Attestation
Use Scenario: Verifying firmware image authenticity before loading into main processor memory during cold boot. IC Role / Device Role / Timing Role: TPM acts as root-of-trust anchor - measures BIOS/UEFI hash, signs result with embedded RSA key, and stores PCR values in protected registers. Use Value: Prevents unauthorized firmware execution by enforcing cryptographic chain-of-trust; leverages hardware-accelerated RSA signing (≤100ms) and immutable PCR storage.	Use Scenario: Reporting current system configuration (e.g., driver versions, OS patch level) to remote management server for compliance validation. IC Role / Device Role / Timing Role: TPM generates quote signature over Platform Configuration Registers (PCRs) using its FIPS-certified RSA engine and internal private key. Use Value: Enables verifiable remote attestation - remote party confirms system state matches expected baseline using public-key cryptography validated against TPM's certified RNG and SHA engine.
Sealed Storage Key Management	Hardware Physical Presence Enforcement
Use Scenario: Encrypting sensitive credentials (e.g., Wi-Fi PSK, TLS private keys) so they decrypt only when platform configuration matches pre-sealing state. IC Role / Device Role / Timing Role: TPM binds encryption key to specific PCR values - decryption fails if any measured component changes (e.g., kernel module load). Use Value: Provides cryptographically enforced access control - keys remain inaccessible after unauthorized firmware or driver modification, leveraging hardware-enforced PCR binding logic.	Use Scenario: Requiring physical button press to authorize critical security operations (e.g., clearing owner hierarchy, disabling TPM). IC Role / Device Role / Timing Role: PP/GPIO pin detects hardware switch closure - TPM firmware validates physical presence flag before executing privileged commands. Use Value: Mitigates remote privilege escalation attacks - prevents malicious software from resetting TPM or altering ownership without local human intervention.

Secure Boot Authentication

Platform Integrity Attestation

Use Scenario: Verifying firmware image authenticity before loading into main processor memory during cold boot.

IC Role / Device Role / Timing Role: TPM acts as root-of-trust anchor - measures BIOS/UEFI hash, signs result with embedded RSA key, and stores PCR values in protected registers.

Use Value: Prevents unauthorized firmware execution by enforcing cryptographic chain-of-trust; leverages hardware-accelerated RSA signing (≤100ms) and immutable PCR storage.

Use Scenario: Reporting current system configuration (e.g., driver versions, OS patch level) to remote management server for compliance validation.

IC Role / Device Role / Timing Role: TPM generates quote signature over Platform Configuration Registers (PCRs) using its FIPS-certified RSA engine and internal private key.

Use Value: Enables verifiable remote attestation - remote party confirms system state matches expected baseline using public-key cryptography validated against TPM's certified RNG and SHA engine.

Sealed Storage Key Management

Hardware Physical Presence Enforcement

Use Scenario: Encrypting sensitive credentials (e.g., Wi-Fi PSK, TLS private keys) so they decrypt only when platform configuration matches pre-sealing state.

IC Role / Device Role / Timing Role: TPM binds encryption key to specific PCR values - decryption fails if any measured component changes (e.g., kernel module load).

Use Value: Provides cryptographically enforced access control - keys remain inaccessible after unauthorized firmware or driver modification, leveraging hardware-enforced PCR binding logic.

Use Scenario: Requiring physical button press to authorize critical security operations (e.g., clearing owner hierarchy, disabling TPM).

IC Role / Device Role / Timing Role: PP/GPIO pin detects hardware switch closure - TPM firmware validates physical presence flag before executing privileged commands.

Use Value: Mitigates remote privilege escalation attacks - prevents malicious software from resetting TPM or altering ownership without local human intervention.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Infineon SLB9665TT2.0	Same TCG TPM 1.2 compliance; SPI interface instead of I²C; 32-pin QFN only; no GPIO-Express mapping.	Requires SPI host controller instead of I²C; lacks pre-mapped GPIO-Express-00 for NV index access; different interrupt signaling (SPI IRQ vs PIRQ#).	Select when SPI interface is preferred and GPIO-Express functionality is not required; verify PCB layout supports SPI routing and timing.
Nuvoton NPCT750YAXX	TCG TPM 1.2 compliant; I²C interface at 400kHz; 32-pin QFN; includes hardware debug disable but no FIPS-140-2 certification for full crypto suite.	Supports identical I²C protocol stack but lacks FIPS-140-2 validation for RNG/AES/SHA/RSA - insufficient for regulated environments requiring cryptographic assurance.	Select for cost-sensitive industrial designs where FIPS certification is not mandated; confirm RNG quality meets application entropy requirements.

Compared with SLB9665TT2.0 and NPCT750YAXX, the AT97SC3205T-U3A1C-20 uniquely combines I²C interface, FIPS-140-2 full-suite certification, GPIO-Express-00 NV indexing, and dual-package flexibility - making it optimal for embedded systems needing certified crypto, minimal bus footprint, and field-upgradeable secure storage.

Availability

AT97SC3205T-U3A1C-20 is available at Aetrix Electronics and suitable for secure boot authentication, platform integrity attestation, and hardware-enforced physical presence applications requiring stable component supply across industrial temperature ranges.

Supply support for AT97SC3205T-U3A1C-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 full product support, documentation, and qualification for legacy Atmel security ICs including the AT97SC3205T series.

The AT97SC3205T belongs to Atmel's TPM security controller family, designed specifically for embedded platforms requiring TCG-compliant hardware root-of-trust with integrated crypto acceleration and certified RNG - targeting industrial gateways, network appliances, and medical edge devices.

FAQ

What is the primary interface type and speed supported by the AT97SC3205T-U3A1C-20?

The AT97SC3205T-U3A1C-20 uses an I²C interface supporting both Standard Mode (100kHz) and Fast Mode (400kHz). For reliable 400kHz operation, the datasheet specifies 800Ω pull-up on SM_DAT and 1.5kΩ on SM_CLK, with strong recommendation for ~50% duty cycle on SM_CLK to ensure communication stability. This interface enables direct connection to host microcontrollers without protocol translation.

Does the AT97SC3205T-U3A1C-20 include certified cryptographic modules?

Yes, the AT97SC3205T-U3A1C-20 includes a FIPS-140-2 certified module covering the Random Number Generator (RNG), HMAC, AES, SHA, and RSA engines. This certification validates the implementation against NIST standards for cryptographic algorithm correctness, key management, and physical security - essential for compliance in government, finance, and healthcare applications.

How does the AT97SC3205T-U3A1C-20 handle low-power operation and wake-up?

The AT97SC3205T-U3A1C-20 automatically enters low-power sleep when idle. Recovery requires simultaneous active-low pulses on both TWI_Wakeup# pins (TSSOP pins 7 and 22). Pin 22 must be tied to GND or VCC (directly or via 4.7kΩ), while pin 7 may float or tie to GND. This dual-signal requirement prevents spurious wake events and enforces intentional system-level control.

What package options are available for the AT97SC3205T-U3A1C-20 and how do they differ physically?

The AT97SC3205T-U3A1C-20 is offered in two packages: 28-pin Thin TSSOP (4.40mm × 9.70mm body, 0.65mm pitch) and 32-pad QFN (4.00mm × 4.00mm body, 0.40mm pitch). The QFN has a smaller footprint and better thermal performance due to its exposed center pad tied to GND, while the TSSOP offers easier manual soldering and probe access. Both are RoHS-compliant and support industrial temperature range (-40°C to +85°C).

What is the purpose and configuration requirement for the PP/GPIO pin on the AT97SC3205T-U3A1C-20?

The PP/GPIO pin on the AT97SC3205T-U3A1C-20 serves as the Hardware Physical Presence indicator - active-high signal used to authorize privileged TPM operations like clearing ownership. It has an internal pull-down resistor and defaults to GPIO input mode. If unused, it must be left floating (not tied high/low) to avoid false physical presence detection; tying it high would permanently enable physical presence mode.

AT97SC3205T-U3A1C-20 Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 28-TSSOP (0.173", 4.40mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Programmable:: Not Verified

Applications:: Trusted Platform Module (TPM)

Core Processor:: AVR

Program Memory Type:: EEPROM

Controller Series:: -

RAM Size:: -

Interface:: I2C

Number of I/O:: 4

Voltage - Supply:: 3.3V

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 28-TSSOP

AT97SC3205T-U3A1C-20 FAQ

1.How can I place an order for AT97SC3205T-U3A1C-20 through Aetrix?

Please submit a Request for Quotation (RFQ) for AT97SC3205T-U3A1C-20 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for AT97SC3205T-U3A1C-20 reliable?

The price and inventory of AT97SC3205T-U3A1C-20 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT97SC3205T-U3A1C-20 is usually 5 days.

3.What payment methods are accepted for AT97SC3205T-U3A1C-20?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT97SC3205T-U3A1C-20 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AT97SC3205T-U3A1C-20?

AT97SC3205T-U3A1C-20 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AT97SC3205T-U3A1C-20 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for AT97SC3205T-U3A1C-20?

For technical support, including AT97SC3205T-U3A1C-20 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT97SC3205T-U3A1C-20 requirements.

6.How does Aetrix verify that AT97SC3205T-U3A1C-20 is sourced from the original manufacturer or authorized distributors?

All AT97SC3205T-U3A1C-20 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AT97SC3205T-U3A1C-20 meets industry standards.

7.What is the process for return or replacement of AT97SC3205T-U3A1C-20?

All AT97SC3205T-U3A1C-20 units undergo pre-shipment inspection (PSI). If there is an issue with AT97SC3205T-U3A1C-20, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The AT97SC3205T-U3A1C-20 part is unused and in its original packaging.

Return procedure for AT97SC3205T-U3A1C-20:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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