SLE 4442 C

Overview

The Infineon Technologies SLE 4442 C is an intelligent 256-byte EEPROM chip card IC featuring a programmable security code (PSC) mechanism. It operates via a synchronous two-wire link protocol compliant with ISO standard 7816-3, utilizing eight contacts for power, reset, clock, and bidirectional I/O. The device includes 256 bytes of main memory, 32 bits of write protection memory, and a 4-byte security memory containing reference data and an error counter. Programming requires a 2.5 ms processing time per byte, supporting a minimum of 10^4 write/erase cycles with a ten-year data retention period.

Feature Summary

• Intelligent 256-byte EEPROM with byte-wise addressing and irreversible write protection for the lowest 32 addresses.
• Programmable Security Code (PSC) logic requiring successful verification to enable write/erase access.
• Synchronous transmission protocol conforming to ISO standard 7816-3 Answer-to-Reset (ATR).
• Integrated Error Counter (EC) that blocks operations after three successive unsuccessful PSC comparisons.

Applications

• Smart card applications requiring secure data storage and authentication.
• Identity systems utilizing Programmable Security Codes for access control.
• Electronic payment cards needing protected memory regions.

Procurement Notes

Verify component authenticity through authorized Siemens or Infineon Semiconductor Group channels. The datasheet specifies that supply does not include licenses for smart card applications; contact INNOVATRON Patents separately for licensing requirements. Confirm specific ordering codes and package availability directly with sales offices as items are listed as 'on request'.

Selection Notes

Select the SLE 4442 C over the SLE 4432 when active security code verification is required to prevent unauthorized memory modification. Ensure the host interface supports the synchronous two-wire protocol and provides necessary pull-up resistors for the open-drain I/O line. Verify that the application environment meets the specified electrical characteristics and temperature ranges defined in the operational information section.

Part Context

The SLE 4442 C is part of the SLE 44xx series of intelligent EEPROMs originally published by Siemens AG Semiconductor Group in 1995. This series distinguishes itself from basic EEPROMs by integrating security logic and protection features specifically designed for chip card environments. The 'C' suffix denotes the chip configuration, distinct from the M2.2 wire-bonded module variant.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. As this is a legacy component originally manufactured by Siemens, potential replacements should be evaluated based on pin compatibility, memory organization, and protocol support. Consult current Infineon Technologies portfolios for modern equivalents.

FAQ

How does the SLE 4442 protect against unauthorized writes?

It uses a Programmable Security Code (PSC) stored in security memory. Write/erase access is blocked until the correct 3-byte verification data is successfully compared against the internal reference data.

What happens if the PSC verification fails three times?

The integrated Error Counter (EC) blocks any subsequent attempts to write or erase memory, effectively locking the device until power is cycled and the procedure is repeated with available counter bits.

Is the write protection memory reversible?

No, the protection memory has PROM functionality. Once a bit is written to protect a corresponding main memory byte, it cannot be erased or changed back.