Microchip Technology 24AA128-I/SN

Overview

24AA128-I/SN from Microchip Technology Inc. is a 128 Kbit (16K × 8) I²C-compatible serial EEPROM with 1.7V–5.5V single-supply operation, 400 kHz maximum clock frequency, and industrial temperature range (−40°C to +85°C). It features 64-byte page write buffer, hardware write-protection via WP pin, and Schmitt-trigger inputs for noise immunity-used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 24AA128-I/SN datasheet, 24AA128-I/SN pinout, 24AA128-I/SN application, or 24AA128-I/SN equivalent, this page delivers verified electrical specs, SOIC-8 package mapping, I²C timing constraints, endurance (1M cycles), and real-world use context for low-voltage, space-constrained designs.

Technical Context

The 24AA128-I/SN implements a two-wire I²C slave interface with fixed 4-bit control code (1010b) and user-configurable A0–A2 address bits enabling up to eight devices on one bus. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and memory control logic supporting byte/page writes and random/sequential reads across the full 128Kbit address space (0000h–3FFFh).

Write operations are self-timed with 5 ms maximum cycle time; read operations support current-address, random, and sequential modes. The device uses open-drain SDA/SCL with external pull-ups, incorporates slope control to suppress ground bounce, and samples WP at the Stop bit to enable/disable writes-no internal write cycle proceeds if WP = VCC.

Key Specifications

Pinout & Package

24AA128-I/SN is packaged in an 8-lead narrow SOIC (SN) per Microchip drawing C04-057-SN: 3.90 mm body width, 1.27 mm lead pitch, gull-wing leads, RoHS-compliant matte tin finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC128-I/SN and AT24C128-10PU-2.7, the 24AA128-I/SN uniquely supports 1.7V operation and offers superior ESD robustness (>4kV), making it the optimal choice for battery-powered or mixed-voltage embedded systems demanding broad supply flexibility and field reliability.

Availability

24AA128-I/SN is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, smart energy metering, automotive body control modules, and portable instrumentation requiring stable component supply across extended temperature and voltage ranges.

Supply support for 24AA128-I/SN 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 Inc. is a leading provider of microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA128-I/SN belongs to Microchip's 24XX128 family of I²C EEPROMs engineered for low-power, high-reliability data logging and configuration storage in space-constrained embedded systems.

FAQ

What is the minimum operating voltage for the 24AA128-I/SN?

The 24AA128-I/SN operates down to 1.7V, enabling direct integration with 1.8V logic families and battery-powered systems where supply voltage may sag below 2.5V. This is a key differentiator from the 24LC128-I/SN, which requires a minimum of 2.5V. At VCC < 2.5V, the 24AA128-I/SN defaults to 100 kHz I²C mode with adjusted timing parameters (e.g., THIGH ≥ 4000 ns).

How does the WP pin function on the 24AA128-I/SN?

The WP (Write-Protect) pin on the 24AA128-I/SN is sampled at the Stop bit of each I²C write command. When tied to VCC, it disables all write operations-including byte, page, and erase-while permitting unlimited reads. The device acknowledges write commands but performs no internal programming. This hardware-level protection prevents accidental or malicious corruption of stored calibration data or firmware parameters.

Can the 24AA128-I/SN be used in AEC-Q100 automotive applications?

The 24AA128-I/SN itself is not AEC-Q100 qualified; however, its industrial temperature grade (−40°C to +85°C) and robust construction make it widely deployed in non-safety-critical automotive subsystems like body control modules and infotainment settings storage. For AEC-Q100–required applications, Microchip offers the 24AA128-E/SN variant, which undergoes additional qualification testing per AEC-Q100 Rev G.

What is the maximum number of 24AA128-I/SN devices that can share one I²C bus?

Up to eight 24AA128-I/SN devices can be cascaded on a single I²C bus using unique combinations of A0, A1, and A2 address pins (1010xxx0 slave address format). Each device must have a distinct 3-bit chip address; all three pins must be hardwired to either VSS or VCC-floating connections are not permitted and will cause bus contention or unpredictable selection.

Does the 24AA128-I/SN support sequential reads across the full 128Kbit memory space?

Yes, the 24AA128-I/SN supports true sequential reads across the entire 0000h–3FFFh address range. After issuing a Start condition and control byte with R/W = 1, the device transmits data starting at the current address pointer and auto-increments after each byte. Upon reaching address 3FFFh, the pointer rolls over to 0000h, enabling continuous streaming without host-side address management.