Microchip Technology 25AA1024-I/S16K

Overview

25AA1024-I/S16K from Microchip Technology Inc. is a 1-Mbit (131,072-byte) SPI serial EEPROM with byte- and page-write capability, 256-byte page size, 6 ms max internal write cycle time, and industrial temperature range (–40°C to +85°C). It operates from 1.8V to 5.5V, supports up to 20 MHz clock at 4.5–5.5V, and features hardware write protection via WP pin and STATUS register control.

For engineers reviewing the 25AA1024-I/S16K datasheet, 25AA1024-I/S16K pinout, 25AA1024-I/S16K application, or 25AA1024-I/S16K equivalent, key selection criteria include SPI interface compatibility, deep power-down current (1 µA), sector-level write protection granularity (32 KB/sector), endurance (1 million erase/write cycles), and AEC-Q100 qualification for automotive use.

Technical Context

The 25AA1024-I/S16K implements a standard SPI Mode 0,0/Motorola-compatible interface with separate SI (data in) and SO (data out) lines, CS-controlled selection, and HOLD pin for transaction suspension without reset. Its memory array is organized as 131,072 × 8 bits, partitioned into 32 sectors of 4,096 bytes each, supporting independent sector erase (10 ms), page erase (6 ms), and chip erase (10 ms).

It integrates nonvolatile STATUS register with BP0/BP1 bits for configurable 0%, 25%, 50%, or 100% array write protection, WPEN bit enabling/disabling hardware WP pin function, and WIP/WEL flags for real-time write status monitoring. Deep power-down mode reduces current to 1 µA at 2.5V/85°C while retaining data and allowing RDID-based wake-up with electronic signature readout.

Key Specifications

Pinout & Package

25AA1024-I/S16K is packaged in an 8-lead SOIJ (Small Outline Integrated Circuit, J-bend) package, pin-compatible with industry-standard 8-pin SOIC footprint. The exposed pad is not present in SOIJ; thermal performance relies on PCB copper area under body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF041A-SSH-T and BR25H1M-2C, the 25AA1024-I/S16K uniquely combines AEC-Q100 qualification, lowest deep power-down current (1 µA), and true byte-write capability without pre-erase - making it optimal for automotive and battery-constrained embedded systems requiring frequent small-data updates.

Availability

25AA1024-I/S16K is available at Aetrix Electronics and suitable for automotive telematics, industrial PLCs, medical infusion pumps, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for 25AA1024-I/S16K 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 25AA1024-I/S16K belongs to Microchip's serial EEPROM product line, engineered for high-reliability, low-power, and automotive-grade nonvolatile data storage in space- and power-constrained embedded systems.

FAQ

What is the maximum SPI clock frequency supported by the 25AA1024-I/S16K?

The 25AA1024-I/S16K supports up to 20 MHz SPI clock frequency when VCC is between 4.5V and 5.5V. At lower voltages - 2.5V ≤ VCC < 4.5V - the maximum clock drops to 10 MHz, and below 2.5V (down to 2.0V), it is limited to 2 MHz. These limits ensure reliable setup/hold timing margins across voltage and temperature ranges specified for the industrial grade.

Does the 25AA1024-I/S16K require external erase before writing new data?

No, the 25AA1024-I/S16K does not require external erase before writing. Its architecture performs automatic, self-timed internal erase during each byte or page write operation. This eliminates the need for explicit erase commands prior to write, simplifying firmware implementation and reducing latency compared to Flash-based alternatives.

How does hardware write protection work on the 25AA1024-I/S16K?

Hardware write protection on the 25AA1024-I/S16K requires both the WP pin to be held low *and* the WPEN bit (bit 7 of STATUS register) set to '1'. When enabled, this combination blocks writes to nonvolatile STATUS register bits (BP0, BP1, WPEN), preventing accidental reconfiguration. All other operations - reads, writes to memory array, and volatile register access - remain fully functional.

What is the purpose of the HOLD pin on the 25AA1024-I/S16K?

The HOLD pin on the 25AA1024-I/S16K suspends an ongoing SPI transaction without resetting internal state or requiring retransmission. When pulled low (with SCK low), it places SO in high-impedance and ignores SI/SCK transitions, allowing the host MCU to service higher-priority interrupts. Resuming requires bringing HOLD high while SCK is low.

Is the 25AA1024-I/S16K compatible with standard SPI Mode 0,0?

Yes, the 25AA1024-I/S16K is fully compatible with SPI Mode 0,0 (CPOL = 0, CPHA = 0): data is sampled on the rising edge of SCK and shifted out on the falling edge. It uses separate SI and SO lines (not bidirectional), matching standard Motorola-style SPI interfaces found in PIC®, ARM Cortex-M, and most general-purpose microcontrollers.