Microchip Technology 25C320T-I/SN

Overview

25C320T-I/SN from Microchip Technology Inc. is a 32 Kbit (4096 × 8) SPI serial EEPROM designed for nonvolatile data storage in embedded control and instrumentation systems. It operates at 4.5–5.5 V, supports up to 3 MHz clock frequency, features 32-byte page write capability, 5 ms max internal write cycle time, and industrial temperature range (−40°C to +85°C). It is commonly used in programmable logic controllers for firmware parameter retention.

For engineers reviewing the 25C320T-I/SN datasheet, 25C320T-I/SN pinout, 25C320T-I/SN application, or 25C320T-I/SN equivalent, key selection criteria include V_CC compatibility (4.5–5.5 V), SPI timing compliance (3 MHz max), page-write efficiency, hardware write protection via WP pin, and SOIC-8 packaging for space-constrained PCB layouts.

Technical Context

The 25C320T-I/SN implements a standard SPI Mode 0,0 interface with separate SI (data-in) and SO (data-out) lines, CS-controlled device selection, and HOLD pin for transaction suspension without reset. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and status register with WIP, WEL, BP0/BP1, and WPEN bits.

Write operations require explicit WREN instruction followed by WRITE command and address/data; writes are page-aligned (32-byte boundaries), and self-timed erase/write cycles eliminate external timing control. Block protection is configurable to lock none, upper 1/4, upper 1/2, or entire memory array via STATUS register programming.

Key Specifications

Pinout & Package

25C320T-I/SN is supplied in an 8-pin Plastic Small Outline Integrated Circuit (SOIC) package with 150 mil body width, RoHS-compliant matte tin lead finish, and standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC320T-I/SN and AT25DF321A-SH-B, the 25C320T-I/SN offers optimal balance of 5 V compatibility, industrial temperature reliability, and minimal firmware overhead for small-parameter storage - making it ideal for cost-sensitive, legacy 5 V designs where pin-for-pin upgrade paths are constrained.

Availability

25C320T-I/SN is available at Aetrix Electronics and suitable for industrial PLCs, medical infusion pumps, automotive body control modules, and smart energy meters requiring stable component supply across extended production lifecycles.

Supply support for 25C320T-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25C320T-I/SN belongs to Microchip's legacy 25XX320 serial EEPROM family, engineered specifically for reliable, low-overhead nonvolatile storage in 5 V industrial and automotive control systems where simplicity, longevity, and proven qualification matter more than raw density or speed.

FAQ

What is the maximum clock frequency supported by the 25C320T-I/SN?

The 25C320T-I/SN supports a maximum serial clock frequency of 3 MHz when operated within its specified V_CC range of 4.5 V to 5.5 V. This value is validated per AC characteristics Table 1-2 in DS21227F, and exceeds the 2 MHz limit of the 25LC320 variant. Operation above 3 MHz may result in timing violations and data corruption.

Does the 25C320T-I/SN support hardware write protection?

Yes, the 25C320T-I/SN supports hardware write protection via the WP pin in conjunction with the WPEN bit in its STATUS register. When WPEN = 1 and WP = low, writes to nonvolatile STATUS register bits (BP0, BP1, WPEN) are disabled - protecting critical protection settings from accidental overwrite. This feature is explicitly documented in Section 2.3 and Table 3-3 of DS21227F.

What package type is used for the 25C320T-I/SN?

The 25C320T-I/SN uses an 8-pin Plastic Small Outline Integrated Circuit (SOIC) package with 150 mil body width, designated by the "SN" suffix in its part number. Pinout matches standard SOIC-8 JEDEC MS-012AC, and the "T" indicates tape-and-reel packaging for automated assembly. This is confirmed in the Device Selection Table and Package Marking section of DS21227F.

How many write/erase cycles does the 25C320T-I/SN guarantee?

The 25C320T-I/SN guarantees 1 million erase/write cycles per memory location, as stated in Table 1-2 (Note 2) and Appendix A of DS21227F. This endurance rating is established by characterization and applies across the full industrial temperature range (−40°C to +85°C), supporting long-term field deployment in frequently updated systems.

Can the 25C320T-I/SN be used with a 3.3 V microcontroller?

No, the 25C320T-I/SN requires a V_CC supply of 4.5 V to 5.5 V and is not rated for 3.3 V operation. Its input thresholds (VIH1 ≥ 2.0 V, VIL1 ≤ 0.8 V) and output drive strength are optimized for 5 V logic. Interfacing with a 3.3 V MCU would require level-shifting circuitry on all SPI lines (CS, SI, SCK, SO, WP, HOLD) to prevent damage or unreliable communication.