Microchip Technology 24AA08HT-I/MS

Overview

24AA08HT-I/MS from Microchip Technology is an 8 Kbit I²C-compatible serial EEPROM organized as four 256 × 8-bit blocks, operating from 1.7V to 5.5V with industrial temperature range (–40°C to +85°C), 400 kHz max clock frequency, and hardware write-protect for the upper half-array (200h–3FFh). It serves as nonvolatile configuration storage in microcontroller-based systems requiring low-power, noise-immune bus interfacing.

For engineers reviewing the 24AA08HT-I/MS datasheet, 24AA08HT-I/MS pinout, 24AA08HT-I/MS application, or 24AA08HT-I/MS equivalent, key selection criteria include V_CC min (1.7V), page write buffer size (16 bytes), WP-enabled half-array protection, Schmitt-trigger SDA/SCL inputs, and MSOP-8 package compatibility with space-constrained PCB layouts.

Technical Context

The 24AA08HT-I/MS implements a slave-only I²C interface with fixed 4-bit device code '1010', block-select addressing (B2–B0), and R/W bit control. Its internal address pointer auto-increments during sequential reads and page writes, while write cycles are self-timed with typical duration of 3 ms and maximum of 5 ms.

Noise immunity is achieved via Schmitt-trigger inputs (hysteresis ≥0.05×V_CC) and input filter spike suppression (≤50 ns), combined with output slope control to suppress ground bounce. The WP pin enables hardware-level write-protection of addresses 200h–3FFh when pulled high, leaving 000h–1FFh fully writable.

Key Specifications

Pinout & Package

24AA08HT-I/MS is supplied in an 8-pin MSOP package (3.0 mm × 3.0 mm, 0.65 mm pitch) with exposed pad option not specified. Pin functions are validated per Microchip DS20002084B, Table 8-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA08HT-I/MS, 24LC08BHT-I/MS trades 1.7V operation for marginally higher ESD rating (6 kV vs. 4 kV), while AT24C08D-MAHM-T offers comparable voltage range but omits hardware write-protection - making 24AA08HT-I/MS optimal for cost-sensitive, low-voltage, security-aware embedded systems.

Availability

24AA08HT-I/MS is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, and consumer appliance user preference storage requiring stable component supply, long-term obsolescence planning, and RoHS-compliant sourcing.

Supply support for 24AA08HT-I/MS 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 24AA08H family was designed specifically for low-voltage, space-constrained embedded systems requiring reliable, low-power I²C EEPROM with hardware write-protection - targeting industrial automation, medical instrumentation, and automotive body electronics.

FAQ

What is the minimum supply voltage required for reliable operation of the 24AA08HT-I/MS?

The 24AA08HT-I/MS operates reliably down to 1.7V across its full industrial temperature range (–40°C to +85°C). Below this threshold, the internal voltage detector disables write operations to prevent data corruption, though read functionality may remain active until V_CC drops below ~1.5V. This makes the 24AA08HT-I/MS suitable for single-cell Li-ion or alkaline battery-powered applications where brown-out conditions are common.

Does the 24AA08HT-I/MS support standard-mode (100 kHz) and fast-mode (400 kHz) I²C communication?

Yes, the 24AA08HT-I/MS supports both I²C standard-mode (100 kHz) and fast-mode (400 kHz) operation. At V_CC ≥2.5V, it achieves the full 400 kHz maximum clock frequency. When V_CC is between 1.7V and 2.5V, the maximum clock frequency is reduced to 100 kHz to ensure timing margin compliance. The 24AA08HT-I/MS does not require mode configuration - speed selection is automatically determined by supply voltage.

How does the hardware write-protect (WP) pin function on the 24AA08HT-I/MS?

When the WP pin of the 24AA08HT-I/MS is driven high (tied to V_CC), write operations to memory addresses 200h–3FFh are inhibited; reads remain fully functional. Addresses 000h–1FFh remain writable regardless of WP state. If WP is tied to V_SS or left floating, full array write access is enabled. This half-array protection is implemented entirely in hardware and requires no firmware intervention.

What is the page write buffer size of the 24AA08HT-I/MS, and how does it affect write performance?

The 24AA08HT-I/MS features a 16-byte page write buffer. This allows up to 16 consecutive bytes to be loaded into the buffer and written to memory in a single self-timed cycle (typ. 3 ms), reducing I²C bus occupancy by up to 16× compared to individual byte writes. Page boundaries align to 16-byte intervals (e.g., 000h–00Fh, 010h–01Fh); crossing a boundary causes wraparound within the current page rather than spanning pages.

Is the 24AA08HT-I/MS pin-compatible with other Microchip 8 Kbit I²C EEPROMs in MSOP-8 packages?

Yes, the 24AA08HT-I/MS is pin-compatible with 24LC08BHT-I/MS and other members of the 24XX08H family in the MSOP-8 package (e.g., 24AA08H-I/MS, 24LC08BH-I/MS). All share identical pin assignments, electrical characteristics, and memory organization. The primary distinction lies in V_CC operating range: 24AA08HT-I/MS supports 1.7–5.5V, while 24LC08BHT-I/MS requires ≥2.5V.