Microchip Technology 24AA32AFT-I/SN

Overview

24AA32AFT-I/SN from Microchip Technology Inc. is a 32 Kbit I²C-compatible serial EEPROM organized as 4K × 8-bit, operating from 1.7V to 5.5V with industrial temperature range (−40°C to +85°C), 400 μA max read current, 1 μA max standby current, and hardware write-protect for upper 1/4 array (C00h–FFFh). It serves in low-power embedded systems requiring nonvolatile parameter storage.

For engineers reviewing the 24AA32AFT-I/SN datasheet, 24AA32AFT-I/SN pinout, 24AA32AFT-I/SN application, or 24AA32AFT-I/SN equivalent, key selection considerations include V_CC min (1.7 V), page write buffer size (32 bytes), I²C clock compatibility (100/400 kHz), and WP-enabled quarter-array protection - all critical for battery-powered, space-constrained, and fail-safe designs.

Technical Context

The 24AA32AFT-I/SN implements a two-wire I²C interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce. Its internal address counter supports current-address, random, and sequential reads, while the 32-byte page write buffer enables efficient bulk writes without host-side timing constraints.

Write protection is implemented via the dedicated WP pin, which-when tied to V_CC-inhibits writes only to addresses C00h–FFFh (16 KB), leaving lower 3/4 of memory fully writable. The device uses self-timed erase/write cycles (≤5 ms) and features >1 million endurance cycles with >200 years data retention.

Key Specifications

Pinout & Package

24AA32AFT-I/SN is supplied in an 8-lead SOIC package (3.90 mm width), RoHS-compliant and Pb-free, with standard 1.27 mm pitch and JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA32AFT-I/SN, the 24LC32AFT-I/SN excludes sub-2.5 V operation but maintains full compatibility above that threshold, while the AT24C32D-SSHM-T trades hardware-based quarter-array protection for broader vendor availability and simplified sourcing - making it viable where system-level write control suffices.

Availability

24AA32AFT-I/SN is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, medical sensor hubs, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 24AA32AFT-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 microcontroller, analog, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA32AFT-I/SN belongs to Microchip's 24XX32AF family of I²C serial EEPROMs, engineered specifically for ultra-low-power, space-constrained embedded applications demanding high reliability and extended data retention.

FAQ

What is the minimum supply voltage for reliable operation of the 24AA32AFT-I/SN?

The 24AA32AFT-I/SN operates reliably down to 1.7 V across its full industrial temperature range (−40°C to +85°C). Below 2.5 V, maximum I²C clock frequency is limited to 100 kHz; at 2.5 V and above, it supports up to 400 kHz. This allows direct integration into 1.8 V systems without level-shifting circuitry, reducing BOM cost and board area. The 24AA32AFT-I/SN maintains full functionality-including page writes and write-protect-at all voltages within this range.

How does the write-protect (WP) pin function on the 24AA32AFT-I/SN?

On the 24AA32AFT-I/SN, the WP pin provides hardware-level write inhibition for the upper 1/4 of memory (addresses C00h–FFFh) when pulled high to V_CC. Writes to this region are blocked, but reads remain fully functional. When WP is tied to V_SS, full memory access is enabled. The pin is sampled at the Stop condition of each write command, so toggling WP mid-operation has no effect. This feature ensures critical calibration or security data stored in the protected zone remains immutable during routine firmware updates - a key reliability mechanism in the 24AA32AFT-I/SN.

What is the maximum page write size supported by the 24AA32AFT-I/SN?

The 24AA32AFT-I/SN supports a maximum page write size of 32 bytes. Page writes must be confined within a single physical page boundary - i.e., starting address modulo 32 must equal zero - otherwise data wraps to the beginning of the same page. This constraint is enforced by the internal address pointer, which increments only on successful byte writes. Because the 24AA32AFT-I/SN's 4K memory is divided into 128 pages of 32 bytes each, proper firmware alignment ensures optimal throughput and avoids unintended overwrites during bulk programming.

Does the 24AA32AFT-I/SN require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA32AFT-I/SN requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. Recommended values are 2 kΩ for 400 kHz operation and 10 kΩ for 100 kHz, referenced to the same V_CC rail powering the 24AA32AFT-I/SN. These values ensure rise times meet I²C specification limits while minimizing power consumption. Failure to install pull-ups will prevent communication, as neither SDA nor SCL can drive high - a fundamental requirement of the I²C protocol implemented in the 24AA32AFT-I/SN.

What is the endurance rating and data retention specification for the 24AA32AFT-I/SN?

The 24AA32AFT-I/SN is rated for more than 1,000,000 erase/write cycles and guarantees data retention exceeding 200 years at +85°C ambient temperature. These specifications are characterized and ensured per Microchip's qualification standards - not merely typical values. The 200-year retention applies to data stored at maximum operating temperature and accounts for worst-case charge leakage mechanisms in the floating-gate EEPROM cells. This makes the 24AA32AFT-I/SN suitable for infrastructure equipment and medical devices where field replacement is impractical, directly supporting long-lifecycle design goals.