Microchip Technology AT97SC3204-U4A13-20

Overview

AT97SC3204-U4A13-20 from Microchip Technology (formerly Atmel) is a TCG v1.2-compliant Trusted Platform Module (TPM) IC implementing hardware-accelerated 2048-bit RSA and SHA-1 cryptography, with on-chip AVR 8-bit RISC CPU, 21-key EEPROM storage, and tamper-evident physical security circuitry for PC and embedded system integrity verification. It operates at 3.0–3.6 V over –40°C to +85°C.

For engineers reviewing the AT97SC3204-U4A13-20 datasheet, AT97SC3204-U4A13-20 pinout, AT97SC3204-U4A13-20 application, or AT97SC3204-U4A13-20 equivalent, key selection considerations include LPC interface compliance, industrial temperature range support, hardware RNG availability, TPM firmware programmability, and 28-pin TSSOP mechanical compatibility.

Technical Context

The AT97SC3204-U4A13-20 implements the Trusted Computing Group (TCG) TPM v1.2 specification using an integrated Atmel AVR 8-bit RISC CPU core, enabling firmware-upgradable cryptographic services without host processor dependency. Its dedicated crypto engine accelerates RSA-2048 signing/verification and SHA-1 hashing (50 µs per 64-byte block).

Physical security includes voltage, frequency, and temperature tamper detection circuits; nonvolatile key storage resides in reliable on-chip EEPROM (no battery required); and a true hardware random number generator (RNG) feeds entropy into cryptographic operations.

Key Specifications

Pinout & Package

AT97SC3204-U4A13-20 is housed in a 28-lead TSSOP package (9.7 mm × 4.4 mm, 0.65 mm pitch), optimized for LPC bus integration in space-constrained PC and embedded control applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SLB9670 and NPCT750, the AT97SC3204-U4A13-20 delivers drop-in LPC compatibility for legacy x86 platforms, lower pin count for cost-sensitive motherboard layouts, and proven qualification across industrial temperature ranges - making it optimal for retrofitting or maintaining existing TPM-enabled systems.

Availability

AT97SC3204-U4A13-20 is available at Aetrix Electronics and suitable for secure boot verification, IP protection in printers, server platform integrity, and set-top box content protection requiring stable component supply and long-term lifecycle assurance.

Supply support for AT97SC3204-U4A13-20 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 its secure authentication product lines, delivering silicon-proven cryptographic ICs for industrial, computing, and consumer markets.

The AT97SC3204-U4A13-20 belongs to Microchip's CryptoController™ TPM family, designed specifically to provide standards-based, hardware-rooted trust for PC platforms and embedded systems requiring certified platform integrity and remote attestation.

FAQ

What is the primary interface protocol supported by the AT97SC3204-U4A13-20?

The AT97SC3204-U4A13-20 uses the Low Pin Count (LPC) bus interface, compliant with Intel's LPC specification. This allows direct connection to x86 chipset southbridges without level-shifting or protocol translation. The AT97SC3204-U4A13-20 supports standard LPC timing and command sets defined in TCG v1.2, enabling seamless integration into PC motherboards and industrial controllers with existing TPM firmware support.

Does the AT97SC3204-U4A13-20 support firmware updates in the field?

Yes, the AT97SC3204-U4A13-20 supports field-upgradable firmware via its LPC interface. Updates are cryptographically signed and verified before execution, preserving integrity against malicious modification. This capability allows security patches and algorithm enhancements to be deployed post-manufacture - a key requirement for maintaining long-term compliance with evolving threat models and certification standards like FIPS 140-2.

What is the maximum number of cryptographic keys the AT97SC3204-U4A13-20 can store securely?

The AT97SC3204-U4A13-20 provides on-chip EEPROM storage for up to 21 user-defined cryptographic keys, each protected by hierarchical authorization policies. These keys are isolated from general-purpose memory and accessible only through authenticated TPM commands. The AT97SC3204-U4A13-20 enforces strict access controls, including password-based authorization and locality checks, ensuring keys remain inaccessible even if the host system is compromised.

Is the AT97SC3204-U4A13-20 qualified for industrial temperature operation?

Yes, the AT97SC3204-U4A13-20 is specified for operation from –40°C to +85°C, meeting industrial-grade environmental requirements. This qualification is confirmed in official Microchip documentation and applies to the U4A13-20 variant. The AT97SC3204-U4A13-20 maintains full TCG v1.2 functionality across this range, including crypto acceleration performance and tamper detection sensitivity - making it suitable for deployment in printers, network equipment, and set-top boxes exposed to uncontrolled thermal environments.

How does the AT97SC3204-U4A13-20 implement physical security against tampering?

The AT97SC3204-U4A13-20 integrates dedicated tamper-detection circuitry monitoring supply voltage, operating frequency, and die temperature. Any deviation outside calibrated thresholds triggers immediate zeroization of all cryptographic keys and sensitive data in EEPROM. This hardware-enforced response occurs autonomously, independent of firmware execution - preventing attackers from disabling protections via software exploits or glitching attacks. The AT97SC3204-U4A13-20 also includes layout-level shielding and sensor redundancy to resist probing and fault injection.