Microchip Technology 25LC1024-I/P

Overview

25LC1024-I/P from Microchip Technology Inc. is a 1-Mbit (131,072-byte) SPI serial EEPROM with byte/page write, page/sector/chip erase, and hardware write protection via WP pin and STATUS register. It operates from 2.5V to 5.5V, supports up to 20 MHz clock at 4.5–5.5V, features 256-byte pages, and delivers 1 million erase/write cycles with >200-year data retention - used in industrial control firmware storage and calibration data logging.

For engineers reviewing the 25LC1024-I/P datasheet, 25LC1024-I/P pinout, 25LC1024-I/P application, or 25LC1024-I/P equivalent, key selection factors include its SPI interface timing compliance (TCSH ≥50 ns at 2.5V), deep power-down current (1 µA at +85°C), sector-level write protection granularity (32 KB per sector), and AEC-Q100 qualification for extended temperature operation.

Technical Context

The 25LC1024-I/P implements a true SPI Mode 0,0 interface with separate SI/SO lines and dedicated CS, SCK, HOLD, and WP pins. Its internal architecture includes a 256-byte page latch, HV generator for EEPROM programming, and status register with WIP/WEL/BP0/BP1 bits enabling real-time write monitoring and configurable block protection.

It supports three nonvolatile erase modes - Page Erase (6 ms), Sector Erase (10 ms), and Chip Erase (10 ms) - all self-timed and initiated by CS high transition after valid instruction/address sequence. The HOLD pin suspends ongoing SPI transfers without resetting internal state, allowing host interrupt servicing while preserving command context.

Key Specifications

Pinout & Package

25LC1024-I/P uses an 8-lead PDIP package (0.300" wide), with lead finish matte tin and RoHS-compliant construction. Pin 1 is CS, pin 8 is VCC, and the exposed pad on DFN-S variants is not present in this PDIP variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF041A-SSH-T and M95M02-DRMN6TP/K, the 25LC1024-I/P uniquely combines AEC-Q100 qualification, HOLD pin for deterministic interrupt response, and 1 µA deep power-down - making it optimal for safety-aware industrial and automotive systems requiring robust, low-power nonvolatile storage.

Availability

25LC1024-I/P is available at Aetrix Electronics and suitable for industrial PLCs, automotive ECUs, medical audit logging, and smart meter firmware patch storage requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 25LC1024-I/P 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 25LC1024-I/P belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power, SPI-based nonvolatile storage in harsh environments - emphasizing endurance, data retention, and automotive-grade qualification.

FAQ

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

The 25LC1024-I/P supports up to 20 MHz SPI clock frequency when VCC is 4.5V to 5.5V. At lower supply voltages (2.5V ≤ VCC < 5.5V), the maximum clock frequency is reduced to 10 MHz to ensure timing margin compliance across temperature. These limits are defined in Table 1-2 AC Characteristics and apply to both read and write operations. The 25LC1024-I/P must be operated within these constraints to guarantee reliable communication and avoid setup/hold violations.

Does the 25LC1024-I/P require external erase before writing new data?

No, the 25LC1024-I/P does not require external erase before writing. Its architecture performs automatic self-timed erase during each byte or page write operation. This eliminates the need for pre-erase commands in typical usage. However, explicit Page Erase (6 ms), Sector Erase (10 ms), or Chip Erase (10 ms) instructions are available for bulk operations - useful when overwriting large contiguous blocks. All erase and write cycles are internally managed and triggered by CS high transition after valid instruction sequences.

How does hardware write protection work on the 25LC1024-I/P?

Hardware write protection on the 25LC1024-I/P is controlled jointly by the WP pin (Pin 3) and the WPEN bit (bit 7) in the STATUS register. When WPEN = 1 and WP = low, writes to nonvolatile STATUS register bits (BP0, BP1, WPEN) are disabled - preventing accidental configuration lockout. If WPEN = 0, the WP pin has no effect. This dual-control mechanism allows safe deployment in systems where WP may be grounded, while retaining ability to configure protection during initial programming. The 25LC1024-I/P datasheet confirms this behavior in Table 3-4.

What is the purpose of the HOLD pin on the 25LC1024-I/P?

The HOLD pin (Pin 7) on the 25LC1024-I/P suspends ongoing SPI communication without resetting the internal command state. When pulled low while SCK is low, the device immediately tri-states SO and ignores further SI/SCK transitions, allowing the host microcontroller to service higher-priority interrupts. Communication resumes from the exact bit position when HOLD is returned high - eliminating the need to restart multi-byte transfers. This deterministic pause capability is critical in real-time systems using the 25LC1024-I/P for configuration or logging.

Is the 25LC1024-I/P compatible with standard SPI Mode 0,0?

Yes, the 25LC1024-I/P is fully compatible with SPI Mode 0,0 (CPOL = 0, CPHA = 0): data are sampled on the rising edge of SCK and output on the falling edge. Its SI input latches on SCK rising edge, and SO output updates after SCK falling edge - matching standard SPI master timing. The device also supports Mode 1,1 (per Figure 1-2), but default operation and all timing specifications in DS20002064E assume Mode 0,0. No configuration register setting is needed to enable this mode; it is inherent to the 25LC1024-I/P's physical interface design.