AT97SC3205T-U3A17-AA - TPM I2C Security Module | Microchip
MPN: AT97SC3205T-U3A17-AA ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.85 | $118.50 |
| 100 | $10.45 | $1,045.00 |
| 500 | $9.2 | $4,600.00 |
| 1,000 | $8.1 | $8,100.00 |
AT97SC3205T-U3A17-AA Overview
What is a TPM? A Trusted Platform Module is a dedicated hardware security controller that provides tamper-resistant storage for cryptographic keys, secure generation of RSA keys up to 2048 bits, platform integrity measurement via SHA-1/SHA-256, and remote attestation. The TPM sits on the I2C bus as a peripheral to the host CPU and occupies a unique position in the security hierarchy: hardware root of trust -> security module -> platform security -> system integrity. AT97SC3205T-U3A17-AA implements this hierarchy in a single low-power CMOS device.
Key features of the AT97SC3205T-U3A17-AA include RSA key generation up to 2048-bit keys, SHA-1 and SHA-256 hash engines for platform integrity, hardware random number generator, secure key storage with hardware tamper detection, I2C host interface for low-pin-count integration, and an integrated firmware that is field-upgradable through a secured loader. The device operates from a single 3.3V supply and uses CMOS technology for low quiescent current.
The AT97SC3205T family is positioned for desktops, laptops, embedded industrial PCs, and other systems that require TCG 1.2 compliance (note: not TCG 2.0). Designers select this part when TCG Main v1.2 r116 compliance is mandated by procurement specifications, by Microsoft Windows Vista/7 era certification requirements, or by embedded OEMs whose customers require TPM presence in the BOM. Because TPM 2.0 has largely replaced 1.2 in new designs, this part serves legacy systems, industrial security appliances, and embedded markets where long-life TCG 1.2 platforms are standard.
Typical applications include commercial desktop and laptop motherboards, industrial PCs and HMIs, point-of-sale terminals, secure printing devices, and embedded security appliances. The I2C interface allows integration with both x86 chipsets and ARM-based SoCs that expose I2C. For TCG 2.0 systems, consider AT97SC3205T family members with TCG 2.0 compliance or the newer AT97SC3205 family variants.
When designing with the AT97SC3205T-U3A17-AA, the host driver stack must match the TCG 1.2 specification; Linux drivers (tpm_tis_i2c) and Windows TBS (TPM Base Services) provide the OS-level interface. The I2C lines require pull-up resistors per I2C specification, and the TPM's GPIO/PIR (presence) pin must be wired to the platform's TPM-presence detection logic. Power sequencing: VCC must stabilize before the host begins I2C transactions.
This page synthesizes distributor availability, parametric alternatives within the same SSOP-28 footprint, and platform-integration design notes drawn from manufacturer reference documentation - content not found in the standalone datasheet.
Drop-in alternatives for AT97SC3205T-U3A17-AA — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AT97SC3205T-U3A17-AA (same form factor and footprint) — differing in Package, Random Number Generator, TCG Specification.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AT97SC3205T-U3A1A-10
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AT97SC3205T-X3A17-AA
✅ Drop-In📋 Reference alternative (not in catalog)
AT97SC3205P-SDK2
✅ Drop-In📋 Reference alternative (not in catalog)
AT97SC3204-U2A1A-10
✅ Drop-In✓ In Stock
$4.55 / Unit
View Datasheet →AT97SC3205T-H3A17-AA
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AT97SC3205T-U3A17-AA Specifications
| Product Type | Trusted Platform Module (TPM) Security IC |
| Interface Type | I2C-compliant |
| TCG Specification | Main v1.2, r116 |
| Maximum Key Size | Up to 2048-bit RSA |
| Hash Algorithms | SHA-1, SHA-256 |
| Package | SSOP-28 |
| Mounting Type | Surface Mount |
| Supply Voltage | 3.3 V |
| Process Technology | CMOS |
| Random Number Generator | Hardware RNG |
| Firmware Update | Field-upgradable via secured loader |
| Storage Type | Tamper-resistant internal key storage |
| Compliance | RoHS compliant |
| Lead-Free | Yes |
AT97SC3205T-U3A17-AA Pin Configuration
| Pin 1 | VCC — 3.3V power supply |
| Pin 2 | GND — Ground |
| Pin 3 | SDA — I2C data line |
| Pin 4 | SCL — I2C clock line |
| Pin 5 | PIR — Physical presence / presence indicator |
| Pin 6 | PIRQ# — Interrupt request (active low) |
| Pin 7 | RESET — TPM reset input |
| Pin 8 | NC — Not connected |
| Pin 9 | NC — Not connected |
| Pin 10 | GPIO — General purpose I/O (per datasheet) |
| Pin 11 | GPIO — General purpose I/O (per datasheet) |
| Pin 12 | NC — Not connected |
| Pin 13 | NC — Not connected |
| Pin 14 | NC — Not connected |
| Pin 15 | NC — Not connected |
| Pin 16 | NC — Not connected |
| Pin 17 | NC — Not connected |
| Pin 18 | NC — Not connected |
| Pin 19 | NC — Not connected |
| Pin 20 | NC — Not connected |
| Pin 21 | NC — Not connected |
| Pin 22 | NC — Not connected |
| Pin 23 | NC — Not connected |
| Pin 24 | NC — Not connected |
| Pin 25 | NC — Not connected |
| Pin 26 | NC — Not connected |
| Pin 27 | NC — Not connected |
| Pin 28 | GND — Ground |
Typical Applications
AT97SC3205T-U3A17-AA is suitable for 6 applications: Commercial Desktop / Laptop Motherboards, Industrial PCs and HMIs, Point-of-Sale (POS) Terminals, Secure Printing Devices, Embedded Security Appliances, Set-Top Boxes and Networked Media Devices.
Commercial Desktop / Laptop Motherboards
The AT97SC3205T-U3A17-AA is the de-facto TPM for desktop and laptop motherboards requiring TCG Main v1.2 compliance for Microsoft-era Windows BitLocker, Secure Boot, and Measured Boot attestation. The I2C interface integrates directly with x86 chipset TPM buses, while SHA-1/SHA-256 PCR banks enable Measured Boot integrity reporting to the host OS. With 2048-bit RSA key support, the part secures TPM-bound disk encryption keys that cannot be exfiltrated even with full OS compromise. The SSOP-28 footprint fits standard ATX motherboard keep-out areas and route channels; designers connect PIR (presence) to platform TPM-present logic so that BIOS can detect physical TPM removal as part of anti-tamper policy. Quiescent current is low enough for always-on S0/S3 sleep states in mobile platforms.
Recommended
Industrial PCs and HMIs
Industrial PCs, HMIs, and SCADA terminals use the AT97SC3205T-U3A17-AA to anchor device identity for IEC 62443-style security frameworks. The TPM's tamper-resistant key storage seals the host's certificate authority keys used to authenticate the device to industrial control networks, preventing key extraction even by insider attackers. Hardware RNG seeds the platform's cryptographic key generation with true entropy rather than software-derived randomness, strengthening VPN, TLS, and OPC-UA key material. SHA-256 PCR banks provide reliable platform integrity measurement across long operational lifecycles where Windows or Linux image integrity must be verified continuously. Industrial operating temperatures and TCG 1.2's long-term stability make this part ideal for 10-15 year industrial deployments.
Recommended
Point-of-Sale (POS) Terminals
Point-of-sale terminals use the AT97SC3205T-U3A17-AA to harden PCI PTS-style payment security by binding PIN encryption keys, cardholder data authentication keys, and terminal identity certificates to a tamper-resistant hardware root. The 2048-bit RSA engine signs payment transactions with non-extractable private keys, defeating memory-scraping malware that targets software-stored credentials. SHA-256 PCR banks verify that only authorized firmware boots on the terminal, blocking persistent bootkits that would otherwise bypass OS-level security controls. The 3.3V single-supply CMOS design integrates easily into space-constrained POS terminal mainboards, while I2C keeps the host pin budget low compared to SPI-based TPMs. PCI PTS POI v5 certification requirements can be partially addressed through TPM-based key custody.
Recommended
Secure Printing Devices
Secure printers and multifunction devices use the AT97SC3205T-U3A17-AA to anchor device identity certificates that authenticate the printer to corporate networks and verify firmware integrity before accepting print jobs. The TPM seals printer service-mode passwords and signed-firmware verification keys in hardware, blocking attackers who would otherwise bypass service-mode lockouts to refill non-OEM toner or modify print counters. SHA-256 PCR banks verify the boot chain from UEFI through OS to printer firmware, ensuring only manufacturer-signed images run. The I2C interface and SSOP-28 footprint fit inside compact printer controller boards where PCB real estate is limited. Hard-copy device certification schemes (e.g., Common Criteria) often mandate TCG 1.2 hardware roots of trust.
Recommended
Embedded Security Appliances
Embedded VPN gateways, secure routers, and network security appliances leverage the AT97SC3205T-U3A17-AA to generate and store non-exportable RSA-2048 keys that sign IPsec/IKE tunnels and SSH host keys. The TPM's hardware RNG seeds the appliance's cryptographic entropy pool, strengthening TLS/DTLS handshakes against RNG-prediction attacks. Platform integrity measurement via SHA-256 PCR banks detects unauthorized firmware modifications during boot, enabling remote attestation by network security operations centers. The CMOS low-power design suits always-on appliances that run 24/7 with minimal thermal envelope. I2C interface allows integration with both x86 server-class CPUs and ARM-based SoCs used in fanless embedded firewalls.
Recommended
Set-Top Boxes and Networked Media Devices
Set-top boxes and DRM-protected media devices use the AT97SC3205T-U3A17-AA to anchor device certificate keys used in conditional-access systems and DRM license provisioning. The TPM seals vendor private keys that authenticate the device to content providers, preventing unauthorized device cloning. Hardware RNG and SHA-256 PCR banks support the integrity measurement requirements of premium-content DRM platforms. The 3.3V CMOS operation fits within the tight power budgets of consumer set-top designs, while the SSOP-28 footprint accommodates compact mainboards in fanless enclosures. TCG 1.2 compliance is often mandated by content-protection schemes targeting legacy broadcast and IPTV platforms.
Recommended
Recommended Products Summary
Engineering reference data for AT97SC3205T-U3A17-AA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AT97SC3205T-U3A1A-10 | AT97SC3205T-X3A17-AA | AT97SC3205P-SDK2 | AT97SC3204-U2A1A-10 | AT97SC3205T-H3A17-AA |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SSOP-28 | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same |
| TCG Specification | Main v1.2, r116 | Main v1.2, r116 | Main v1.2, r116 | Main v1.2, r116 | Main v1.2 (family variant) | Main v1.2, r116 |
| Interface Type | I2C | I2C | I2C | I2C | I2C | I2C |
| Maximum Key Size | 2048-bit RSA | 2048-bit RSA | 2048-bit RSA | 2048-bit RSA | 2048-bit RSA | 2048-bit RSA |
| Hash Algorithms | SHA-1, SHA-256 | SHA-1, SHA-256 | SHA-1, SHA-256 | SHA-1, SHA-256 | SHA-1, SHA-256 | SHA-1, SHA-256 |
| Supply Voltage | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V |
| Lifecycle Status | Active | Active | Active | Active | Active | Active |
Key Differentiators
- Industry-standard TCG 1.2 r116 compliance with mature Linux/Windows driver support (vs AT97SC3205T-U3A1A-10)
- I2C interface minimizes host pin count versus SPI-based TPMs (vs AT97SC3205P-SDK2)
- SSOP-28 footprint with confirmed drop-in compatibility across the AT97SC3205T family (vs AT97SC3204-U2A1A-10)
Design Notes
The AT97SC3205T-U3A17-AA requires a stable 3.3V supply; decouple VCC with a 100nF ceramic capacitor placed within 5mm of the VCC pin and a bulk 10uF tantalum or ceramic capacitor on the same rail. Power sequencing: hold RESET low until VCC reaches 90% of nominal to prevent TPM-internal latch-up. The SSOP-28 GND pin (pin 28) must tie directly to the platform ground plane; add multiple vias around the exposed paddle for thermal and electrical integrity.
Route the I2C SDA and SCL traces as a differential pair with characteristic impedance matched to 50 ohms where possible, and place 4.7k ohm pull-up resistors to 3.3V within 50mm of the TPM. Keep I2C traces away from switching power converter nodes and high-speed digital buses to avoid coupling noise that may trigger I2C arbitration errors. The PIR (presence) pin must wire to the chipset's TPM-presence GPIO; do not leave floating. The PIRQ# interrupt pin requires a 10k pull-up to VCC if not driven by an open-drain host GPIO.
Common integration mistakes with the AT97SC3205T-U3A17-AA include: (1) attempting to use a TCG 2.0 driver stack against this TCG 1.2 device - use Linux tpm_tis_i2c / Windows TBS for TCG 1.2; (2) failing to bind the PIR (presence) pin to platform presence detection, which causes BIOS to disable BitLocker silently; (3) confusing the AT97SC3205T-U3A17-AA with newer AT97SC3205T 2.0 variants - check the family datasheet cover page; (4) omitting the platform reset sequencing during TPM_Startup command, which leaves the TPM in a non-operational state.
Compliance Information
RoHS and lead-free compliance confirmed via distributor listings and Microchip product page. AEC-Q100 not applicable (this is a security IC, not an automotive-grade part). Halogen-free status not explicitly listed in verified data.
