Microchip Technology 25LC1024-I/MF

Overview

25LC1024-I/MF from Microchip Technology Inc. is a 1-Mbit (131,072-byte) SPI serial EEPROM with byte- and page-write capability, 256-byte page size, 20 MHz max clock speed at 4.5–5.5V, and industrial temperature range (−40°C to +85°C). It supports Page/Sector/Chip Erase, hardware write protection via WP pin, and Deep Power-Down mode drawing only 1 µA at 2.5V - deployed in embedded control systems for parameter storage and firmware configuration.

For engineers reviewing the 25LC1024-I/MF datasheet, 25LC1024-I/MF pinout, 25LC1024-I/MF application, or 25LC1024-I/MF equivalent, key selection criteria include SPI timing compliance at 2.5V–5.5V VCC, 256-byte page boundary handling, sector-level write protection granularity, and AEC-Q100 qualification for automotive subsystems.

Technical Context

The 25LC1024-I/MF implements an SPI Mode 0,0 or 1,1 interface with separate SI/SO lines, requiring CS low and HOLD high for normal operation. Its internal architecture includes a status register with WIP/WEL/BP0/BP1 bits, programmable block protection (0%, 25%, 50%, or 100% array), and hardware write-enable logic gated by WPEN bit and WP pin state.

It executes self-timed internal write cycles (6 ms max for page write or page erase; 10 ms for sector or chip erase), supports hold functionality to pause ongoing transfers without sequence restart, and enters Deep Power-Down on DPD command - exiting only via RDID with electronic signature readout.

Key Specifications

Pinout & Package

25LC1024-I/MF uses an 8-lead DFN-S package (3×2 mm, 0.5 mm pitch) with exposed thermal pad (optional VSS connection). Pin numbering follows standard top-view layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF041A-SSH-T, 25LC1024-I/MF offers true byte-write without pre-erase and higher endurance; compared with 25AA1024-I/MF, it trades wider VCC range for higher 20 MHz speed at 4.5–5.5V - making it optimal for 5V industrial control buses.

Availability

25LC1024-I/MF is available at Aetrix Electronics and suitable for industrial automation, automotive subsystems, and medical instrumentation requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant nonvolatile memory.

Supply support for 25LC1024-I/MF 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 25LCxx family delivers SPI serial EEPROMs optimized for reliability-critical embedded systems, emphasizing high endurance, low-power operation, and automotive-grade qualification - targeting applications where data integrity outweighs raw density or speed.

FAQ

What is the maximum clock frequency supported by the 25LC1024-I/MF?

The 25LC1024-I/MF supports up to 20 MHz clock frequency when VCC is 4.5V–5.5V. At lower supply voltages (2.5V–5.5V), the maximum clock rate drops to 10 MHz. These limits are defined in Table 1-2 AC Characteristics and must be respected to ensure reliable SI sampling and SO timing compliance - exceeding them risks data corruption during read/write sequences. The 25LC1024-I/MF does not auto-negotiate speed and relies on host controller adherence to these specs.

How does the HOLD pin function during an active SPI transaction in the 25LC1024-I/MF?

The HOLD pin on the 25LC1024-I/MF suspends ongoing SPI communication when pulled low while SCK is low, placing SO in high-impedance state without resetting the internal address pointer or command state. Transitions on SI and SCK are ignored until HOLD is returned high while SCK remains low. This allows the host MCU to service time-critical interrupts and resume exactly where the transfer left off - a feature confirmed in Section 2.6 and Figure 1-1 of the 25LC1024-I/MF datasheet.

Can the 25LC1024-I/MF perform byte-level writes without erasing the entire page first?

Yes, the 25LC1024-I/MF supports true byte-level writes without prior page or sector erase - a core EEPROM characteristic. Each byte write triggers an internal self-timed write cycle (≤6 ms), and the device automatically refreshes unchanged bytes within the same 256-byte page. This behavior is explicitly stated in the Features section and Figure 3-2 of the 25LC1024-I/MF datasheet, distinguishing it from SPI Flash devices that require erase-before-write.

What protection mechanisms prevent unintended writes to the 25LC1024-I/MF during power-up or brown-out events?

The 25LC1024-I/MF incorporates three layered protections: (1) Power-on write disable circuitry that resets the write-enable latch (WEL) at startup; (2) Hardware write-protection enabled when WP pin is low and WPEN bit is set; and (3) STATUS register write-lock independent of WP pin state. These features are documented in Sections 2.3 and 3.4 of the 25LC1024-I/MF datasheet and ensure data integrity during unstable supply conditions.

Is the 25LC1024-I/MF compatible with standard SPI Mode 0,0 and Mode 1,1 configurations?

Yes, the 25LC1024-I/MF is fully compatible with both SPI Mode 0,0 (CPOL=0, CPHA=0) and Mode 1,1 (CPOL=1, CPHA=1), as confirmed in Figure 1-2 and Figure 1-3 of the datasheet. Data is sampled on the rising edge of SCK (SI) and output on the falling edge (SO) - matching standard SPI timing conventions. Host firmware must configure the controller accordingly; no internal mode selection register is required for 25LC1024-I/MF operation.