Microchip Technology AT24CSW080-UUM0B-T

Overview

AT24CSW080-UUM0B-T from Microchip Technology (formerly Atmel) is an 8-Kbit I²C-compatible serial EEPROM with integrated security register, software write protection, and ultra-thin WLCSP packaging. It delivers 1,024 × 8-bit memory organization, 1 MHz Fast Mode Plus interface support, 128-bit factory-programmed unique serial number, and operates across 1.7V–3.6V supply for low-power embedded systems.

For engineers reviewing the AT24CSW080-UUM0B-T datasheet, AT24CSW080-UUM0B-T pinout, AT24CSW080-UUM0B-T application, or AT24CSW080-UUM0B-T equivalent, key selection considerations include its 4-ball WLCSP footprint, permanent read-only security register, five-level software write protection, 1,000,000 write endurance, and guaranteed uniqueness of the 128-bit serial number across the CS Series.

Technical Context

The AT24CSW080-UUM0B-T implements a true I²C slave interface with Schmitt-triggered, noise-filtered SDA/SCL inputs, supports Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) speeds, and uses address byte prefix 1010b for main EEPROM access and 1011b for security register access. Its internal architecture separates the 8-Kbit user EEPROM (000h–3FFh) from the 32-byte security register (80h–9Fh), with distinct addressing and protection logic.

Write protection is managed via an 8-bit Write Protect Register enabling five configurable block-lock states; the security register includes 16 bytes of factory-programmed read-only serial number (80h–8Fh) and 16 bytes of user-programmable memory (90h–9Fh) that can be permanently locked via software command. Standby current is limited to 0.8 μA max, and self-timed write cycles complete in ≤5 ms.

Key Specifications

Pinout & Package

AT24CSW080-UUM0B-T is housed in a 4-ball Ultra-Thin Wafer-Level Chip Scale Package (WLCSP), code 4U-13, with 0.4 mm pitch and bottom-side solder pads. This package enables minimal PCB footprint (0.83 mm × 0.83 mm) and low profile (<0.35 mm height), ideal for space-constrained portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24CSW080-UUM0B-T, the UUM0A-T offers identical functionality with a different fixed address for bus arbitration, while the M24C08-RMN6TP trades security and miniaturization for package compatibility and lower unit cost in non-secure contexts.

Availability

AT24CSW080-UUM0B-T is available at Aetrix Electronics and suitable for IoT edge node identity, medical device calibration storage, industrial PLC configuration backup, and automotive infotainment settings requiring stable component supply across extended product lifecycles.

Supply support for AT24CSW080-UUM0B-T 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 acquired Atmel in 2016 and continues development of the AT24CSW series as part of its broad serial EEPROM portfolio, emphasizing security, ultra-low power, and advanced packaging.

The AT24CSW080-UUM0B-T belongs to the CS Series of secure serial EEPROMs, designed specifically for applications demanding tamper-resistant device identity, field-updatable secure parameters, and space-constrained deployment in portable and industrial electronics.

FAQ

What is the factory-programmed slave address of AT24CSW080-UUM0B-T?

The AT24CSW080-UUM0B-T has a fixed hardware slave address with A2 = 0 (and no A1 bit for 8-Kbit variants), resulting in a base device address of 10100xxR/W. This address is laser-trimmed during manufacturing and cannot be altered. The full 7-bit address depends on the R/W bit and is used by the I²C master to initiate communication with AT24CSW080-UUM0B-T without external address pins.

Can the 128-bit serial number in AT24CSW080-UUM0B-T be rewritten or erased?

No - the 128-bit serial number in AT24CSW080-UUM0B-T is factory-programmed into the first 16 bytes (80h–8Fh) of the security register and permanently locked during wafer fabrication. It is read-only for the lifetime of the device and guaranteed unique across all CS Series EEPROMs, including AT24CSW04x and AT24CSW08x variants. AT24CSW080-UUM0B-T provides no mechanism to modify this value.

How does software write protection work in AT24CSW080-UUM0B-T?

AT24CSW080-UUM0B-T implements five programmable protection levels via an 8-bit Write Protect Register, controlled by WPB1 and WPB0 bits. These bits define which memory blocks (e.g., top quarter, top half, all but first page) are write-protected. Protection can be made permanent using a dedicated software sequence, after which the register becomes read-only. AT24CSW080-UUM0B-T enforces this at the silicon level - writes to protected regions are ignored and acknowledged, but data remains unchanged.

What is the maximum I²C clock frequency supported by AT24CSW080-UUM0B-T?

AT24CSW080-UUM0B-T supports I²C Fast Mode Plus (FM+) at up to 1 MHz across its full 1.7 V–3.6 V operating range. This is confirmed in the official datasheet (Atmel-47001B, Section "Features") and exceeds standard Fast Mode (400 kHz). The device maintains timing compliance under worst-case voltage and temperature conditions, enabling faster configuration loading in time-sensitive applications using AT24CSW080-UUM0B-T.

Is AT24CSW080-UUM0B-T RoHS-compliant and halogen-free?

Yes - AT24CSW080-UUM0B-T is manufactured in a green package meeting RoHS Directive 2011/65/EU requirements and is both lead-free and halide-free. The 4-ball Ultra-Thin WLCSP (4U-13) package uses SnAgCu (SAC305) solder bumps and complies with JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), making it suitable for standard reflow processes without baking. This environmental compliance is explicitly stated in the datasheet's "Features" section.