Microchip Technology AT24C128W-10SI

Overview

AT24C128W-10SI from Microchip Technology (formerly Atmel) is a 128 Kbit (16,384 × 8) I²C-compatible serial EEPROM optimized for industrial temperature operation (–40°C to +85°C), supporting 2.7V to 5.5V supply, 400 kHz bus speed, and hardware write protection via the WP pin. It serves as nonvolatile configuration storage in embedded controllers, power management units, and sensor calibration modules.

For engineers reviewing the AT24C128W-10SI datasheet, AT24C128W-10SI pinout, AT24C128W-10SI application, or AT24C128W-10SI equivalent, key selection criteria include industrial-grade reliability (100,000 write cycles, 40-year data retention), 64-byte page write capability, Schmitt-trigger inputs for noise immunity, and compatibility with standard 2-wire I²C protocol across voltage ranges.

Technical Context

The AT24C128W-10SI implements a fixed 14-bit internal address counter for random and sequential read operations, with automatic rollover at page boundaries. Its I²C interface conforms to standard open-drain bidirectional signaling, requiring external pull-ups on SDA and SCL, and supports up to four devices on a shared bus using A0/A1 address pins.

Write operations are internally self-timed with a typical duration of 5 ms and maximum of 10 ms; during this period, all inputs are disabled and acknowledge polling is required to detect completion. The device uses proprietary internal biasing on A0/A1 to default to logic low when unconnected, enabling plug-and-play multi-device addressing without external resistors.

Key Specifications

Pinout & Package

AT24C128W-10SI is packaged in an 8-pin JEDEC SOIC (8S1), 0.150" wide, with gull-wing leads and standard footprint compatible with automated PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C128W-10SI, AT24C128B-10SI-2.7 offers lower standby current for energy-constrained designs, while M24128-BRMC6TG provides a non-Microchip alternative with trade-offs in pinout and write-protect behavior - both require validation in target system timing and firmware.

Availability

AT24C128W-10SI is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, and power electronics applications requiring stable component supply, long-term lifecycle assurance, and guaranteed industrial temperature performance.

Supply support for AT24C128W-10SI 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 is a global semiconductor company specializing in microcontrollers, analog components, and memory solutions, with broad industrial and automotive qualification programs.

The AT24C128W-10SI belongs to Microchip's legacy AT24C serial EEPROM product line, designed specifically for reliable, low-power nonvolatile storage in harsh-environment embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the AT24C128W-10SI?

The AT24C128W-10SI supports up to 400 kHz I²C clock frequency when operating within its 2.7V–5.5V supply range. This is confirmed in the AC Characteristics table under "fSCL" for the 2.7V option. Operation at 1 MHz is only specified for 5.0V versions (e.g., AT24C128-10CC), not the -10SI variant. Always verify bus rise/fall times and pull-up strength per the datasheet's AC measurement conditions.

Does the AT24C128W-10SI require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C128W-10SI requires external pull-up resistors on both SDA and SCL lines because it uses open-drain outputs. Typical values range from 2.2 kΩ to 10 kΩ depending on bus capacitance and speed; the datasheet specifies RL = 1.3 kΩ for 2.5V/5V operation and 10 kΩ for 1.8V. Failure to install appropriate pull-ups will prevent proper I²C communication.

How does the Write Protect (WP) pin function on the AT24C128W-10SI?

The WP pin on the AT24C128W-10SI is active-high: when tied to VCC, it disables all write operations to the entire memory array; when tied to GND or left floating (internally pulled down), writes are enabled. This hardware-level protection operates independently of software commands and remains effective even during power transitions, making it ideal for safeguarding critical calibration data.

What package type is used for the AT24C128W-10SI?

The AT24C128W-10SI uses an 8-pin JEDEC-standard SOIC package (designated 8S1), 0.150" wide, with gull-wing leads. This is explicitly listed in the Ordering Information table under "Package" for the -10SI suffix. It is not supplied in PDIP, TSSOP, or dBGA variants for this specific ordering code.

Can multiple AT24C128W-10SI devices share the same I²C bus?

Yes, up to four AT24C128W-10SI devices can share a single I²C bus using the A0 and A1 address pins. Each device is assigned a unique 3-bit chip address prefix (1010xx) where xx is determined by A0/A1 logic levels. When both pins float, they default low, yielding address 0x50; hardwiring combinations yield 0x51, 0x52, or 0x53 - enabling scalable memory expansion without additional buses.