Microchip Technology 25LC320AT-I/SN

Overview

25LC320AT-I/SN from Microchip Technology is a 32-Kbit SPI Serial EEPROM with 4096 × 8-bit organization, 32-byte page size, and industrial temperature range (–40°C to +85°C). It operates at up to 10 MHz clock frequency, supports hardware write protection via WP pin and STATUS register, and delivers 5 µA standby current at 5.5V - ideal for low-power embedded systems requiring nonvolatile configuration storage.

For engineers reviewing the 25LC320AT-I/SN datasheet, 25LC320AT-I/SN pinout, 25LC320AT-I/SN application, or 25LC320AT-I/SN equivalent, key selection considerations include its SOIC-8 narrow-body package, AEC-Q100 qualification, 5 ms max self-timed write cycle, and compatibility with PIC® and other SPI-capable microcontrollers in space-constrained industrial control and automotive subsystems.

Technical Context

The 25LC320AT-I/SN implements a standard SPI Mode 0,0 interface with separate SI and SO lines, CS-controlled selection, and HOLD pin for transaction suspension without reset. Its internal architecture includes an 8-bit instruction register, page latches, and high-voltage generator for EEPROM programming.

It features dual-level write protection: volatile WREN/WRDI latch control and nonvolatile BP0/BP1 bits enabling selective block protection (none, 1/4, 1/2, or full array), plus hardware-enforced protection when WPEN=1 and WP=low. The STATUS register is readable during writes, supporting real-time WIP bit polling.

Key Specifications

Pinout & Package

25LC320AT-I/SN is packaged in an 8-lead Plastic Small Outline (SOIC-N) with 150-mil body width (Microchip package code SN), footprint-compatible with JEDEC MS-012AA. Pin 1 is marked by a beveled corner or notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA320AT-I/SN and AT25DF321A-SHN-T, the 25LC320AT-I/SN provides optimal balance of industrial temperature margin, AEC-Q100 qualification, and proven SPI EEPROM simplicity - making it preferred for cost-sensitive, long-lifecycle embedded systems where parameter integrity outweighs raw density or speed.

Availability

25LC320AT-I/SN is available at Aetrix Electronics and suitable for industrial automation, automotive subsystems, and medical device design requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for 25LC320AT-I/SN 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 25LC320A family was designed specifically for reliable, low-power nonvolatile data storage in automotive and industrial applications - emphasizing robustness, long-term data retention, and seamless SPI integration with Microchip's PIC® and SAM MCU portfolios.

FAQ

What is the maximum clock frequency supported by the 25LC320AT-I/SN?

The 25LC320AT-I/SN supports up to 10 MHz clock frequency when VCC is between 4.5V and 5.5V. At 2.5V ≤ VCC < 4.5V, the maximum clock drops to 5 MHz, and at 1.8V ≤ VCC < 2.5V (not applicable to this part), it would be 3 MHz. Since the 25LC320AT-I/SN has a 2.5V minimum VCC, its operational clock range is 0–10 MHz depending on supply voltage.

Does the 25LC320AT-I/SN require external pull-up resistors on its SPI lines?

No, the 25LC320AT-I/SN does not require external pull-ups on SI, SO, or SCK - these pins are actively driven. However, CS and WP should be pulled high via external resistors (typically 4.7kΩ–10kΩ) to ensure defined logic states during power-up and idle conditions, preventing unintended writes or device selection.

How does the HOLD function behave during an active write cycle in the 25LC320AT-I/SN?

The HOLD pin has no effect on an ongoing internal write cycle in the 25LC320AT-I/SN. Once initiated by CS high, the 5 ms self-timed write proceeds to completion regardless of HOLD state. HOLD only suspends serial communication sequences - not internal EEPROM programming - preserving data integrity during host interrupt servicing.

Can the 25LC320AT-I/SN be used in automotive applications requiring AEC-Q100 compliance?

Yes, the 25LC320AT-I/SN is explicitly AEC-Q100 qualified for Automotive Grade 2 (–40°C to +105°C ambient), as confirmed in Microchip's DS20001828H datasheet. Its qualification covers temperature cycling, humidity testing, and ESD robustness - making it suitable for body electronics, infotainment, and ADAS subsystems where reliability is critical.

What is the purpose of the WPEN bit in the STATUS register of the 25LC320AT-I/SN?

The WPEN (Write-Protect Enable) bit in the 25LC320AT-I/SN STATUS register controls whether the WP pin enforces hardware write protection. When WPEN = 1 and WP = low, writes to nonvolatile STATUS bits are blocked; when WPEN = 0, the WP pin is ignored entirely. This allows safe installation in systems with grounded WP pins while retaining full STATUS register configurability.