Infineon Technologies SLE 4428 C

Overview

SLE 4428 C from Siemens AG is an intelligent 1-KByte (1024 × 8-bit) EEPROM IC for contact-based smart cards, featuring byte-wise write protection, programmable 2-byte security code (PSC), and ISO/IEC 7816-3 synchronous serial interface. It operates at 5 V, supports ≥10⁴ write/erase cycles, and guarantees ≥10-year data retention. Used in secure identification cards requiring tamper-resistant memory with access control.

For engineers reviewing the SLE 4428 C datasheet, SLE 4428 C pinout, SLE 4428 C application, or SLE 4428 C equivalent, key selection criteria include PSC-verified write enablement, irreversible byte-level protection, ISO 7816 contact mapping (C1–C8), and die-level packaging for card embedding.

Technical Context

The SLE 4428 C implements a synchronous three-wire serial bus (CLK, RST, I/O) compliant with ISO/IEC 7816-3, where RST controls data direction and I/O serves as open-drain bidirectional line. Memory access requires Answer-to-Reset initialization followed by command entry using 9-bit control words.

Its security architecture includes a dedicated 2-byte Programmable Security Code register and an error counter that permanently blocks write/erase after eight consecutive incorrect PSC entries. Protection memory is organized as 1024 × 1 bit, with one-time programmable bits per byte.

Key Specifications

Pinout & Package

Package: Bare die (chip form), intended for wire bonding into M2.2 module or direct embedding in PVC/PET smart cards. No plastic or ceramic package; handled as unpassivated silicon die with aluminum bond pads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT88SC0104CA-SU and FM11RF08, the SLE 4428 C uniquely delivers ISO 7816-3 synchronous contact operation with simple 2-byte PSC enforcement and irreversible byte protection-ideal for cost-sensitive, standards-compliant contact smart cards where cryptographic acceleration or RF is unnecessary.

Availability

SLE 4428 C is available at Aetrix Electronics and suitable for government ID issuance, banking card personalization, physical access token manufacturing, and healthcare credentialing requiring stable component supply over extended production lifecycles.

Supply support for SLE 4428 C 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

Siemens AG Semiconductor Group was a leading European semiconductor manufacturer (1994), specializing in chip card ICs, industrial microcontrollers, and analog devices before divesting its semiconductor business to Infineon Technologies in 1999.

The SLE 4428 C belongs to Siemens' SLE 44xx family of contact smart card EEPROMs, designed specifically for ISO 7816-compliant identification and financial applications requiring field-programmable security and long-term data integrity.

FAQ

What is the function of the C4, C6, and C8 pins on the SLE 4428 C?

C4, C6, and C8 are designated "Not Connected" in the official pinout and have no internal connection to the die. They are reserved for mechanical alignment or future compatibility in ISO 7816 card contact layouts but must remain unconnected in circuit design and card embedding.

Can the Programmable Security Code (PSC) be changed after initial programming?

Yes-the PSC can be rewritten multiple times, provided the current PSC is correctly entered first. However, the error counter remains active across PSC changes, and eight cumulative incorrect entries will permanently disable further PSC verification and all write/erase operations.

Is the SLE 4428 C compatible with modern ISO 7816-3 readers?

Yes-it fully complies with ISO/IEC 7816-3:1994 for synchronous transmission, including Answer-to-Reset timing, clock rate limits (fCLK ≤ 5 MHz), and voltage levels (5 V). Modern readers supporting legacy synchronous mode will operate it without firmware modification.

Does the SLE 4428 C require external pull-up resistors on the I/O line?

Yes-an external pull-up resistor (typically 10 kΩ to VCC) is mandatory on the C7 (I/O) pin because the internal driver is open-drain. Without it, data cannot be reliably read or written during command execution or memory access sequences.