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Home > Products > Integrated Circuits (ICs) > Memory > Memory

Microchip Technology 25LC320X-I/ST

Name: 25LC320X-I/ST
Brand: Microchip Technology
SKU: 25LC320X-I/ST
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 25LC320X-I/ST

Manufacturer:: Microchip Technology

Category:: Memory

Package:: 8-TSSOP (0.173", 4.40mm Width)

Datasheet:: 25LC320X-I/ST.pdf

Description:: IC EEPROM 32KBIT SPI 2MHZ 8TSSOP

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Product details

Overview

25LC320X-I/ST from Microchip Technology Inc. is a 32 Kbit (4096 × 8) SPI serial EEPROM with industrial temperature range (−40°C to +85°C), 2 MHz max clock frequency at V_CC = 2.5–5.5 V, and 8-pin TSSOP package. It features hardware write protection via WP pin, HOLD functionality for interrupt-safe pausing, and 32-byte page write capability. It is used in embedded systems for storing calibration data, configuration parameters, and firmware patches.

For engineers reviewing the 25LC320X-I/ST datasheet, 25LC320X-I/ST pinout, 25LC320X-I/ST application, or 25LC320X-I/ST equivalent, key selection criteria include V_CC compatibility (2.5–5.5 V), SPI timing compliance (t_CSH, t_HOLD), endurance (1M E/W cycles), data retention (>200 years), and block protection granularity (1/4, 1/2, or full array).

Technical Context

The 25LC320X-I/ST implements a standard SPI Mode 0,0 interface with separate SI (data in) and SO (data out) lines, requiring CS, SCK, WP, and HOLD control signals. Its internal architecture includes an 8-bit instruction register, STATUS register with WIP/WEL/BP0/BP1 bits, and high-voltage generator for EEPROM programming.

Write operations require explicit WREN instruction followed by WRITE command and address/data; page writes are limited to 32 bytes within the same 32-byte-aligned boundary. The HOLD pin suspends ongoing SPI transfers without resetting the sequence, enabling host MCU to service higher-priority interrupts while preserving transaction state.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory size	32 Kbit (4096 × 8 bits); supports up to 4096 unique byte-addressable locations
Interface	SPI-compatible serial bus (Mode 0,0); requires CS, SCK, SI, SO, WP, HOLD, V_CC, V_SS
Max clock frequency	2 MHz at V_CC = 2.5–5.5 V; defines maximum sustained data throughput (~2 Mbps)
Write cycle time	5 ms maximum internal write time per page or byte; determines minimum delay before status polling or next operation
Endurance & retention	1 million erase/write cycles; >200 years data retention at 85°C - validated for long-life industrial logging
Supply current	500 μA typical read current (V_CC = 2.5 V, f_CLK = 2 MHz); 3 mA max write current; 500 nA standby - enables low-power battery operation
Temperature range	Industrial grade: −40°C to +85°C - qualified for use in programmable logic controllers and sensor nodes

Pinout & Package

25LC320X-I/ST uses an 8-pin Plastic TSSOP (4.4 mm body width) package with ST suffix, pin-compatible with SOIC-8 but thinner and footprint-optimized. Pin 1 is CS; pin 8 is V_CC; no NC pins in this variant.

Pin	Circuit Role	Design Meaning
1 (CS)	Chip Select Input	Active-low enable; deselecting forces SO into high-impedance to share SPI bus with other devices
2 (SO)	Serial Data Output	Tri-state output; data shifted out on falling edge of SCK; high-Z when CS high or HOLD active
3 (WP)	Write-Protect Input	Hardware lock for STATUS register nonvolatile bits when WPEN = 1; grounded to prevent accidental writes
4 (V_SS)	Ground	Reference return path for all digital and internal HV circuits; must be low-impedance
5 (SI)	Serial Data Input	Latches instruction/address/data on rising edge of SCK; accepts MSB-first 8-bit commands
6 (SCK)	Serial Clock Input	Synchronizes all SPI transfers; timing-critical for t_CSH, t_TCSS, t_THD compliance
7 (HOLD)	Hold Input	Pauses ongoing SPI transfer (e.g., during MCU interrupt); requires SCK low to assert/deassert
8 (V_CC)	Supply Voltage	2.5–5.5 V operating range; powers logic, charge pump, and I/O buffers; bypass capacitor required

Key Features

Feature	Design Value
Block write protection	Selectable 0%, 25%, 50%, or 100% array protection via BP0/BP1 bits - prevents corruption of critical firmware sections
HOLD function	Interrupt-safe SPI pause/resume without retransmission - eliminates race conditions during real-time task switching
Power-on write disable	WEL latch resets at power-up; prevents spurious writes during brown-out or reset sequences
Page write buffer	32-byte page write capability - reduces SPI overhead vs. byte-by-byte writes; improves firmware update efficiency
ESD robustness	>4000 V HBM ESD rating - ensures reliability in handling-sensitive industrial assembly environments

Applications

Industrial Sensor Calibration	Medical Device Configuration
Use Scenario: Storing factory-calibrated sensor offset/gain coefficients and linearization tables in portable gas analyzers. IC Role / Device Role / Timing Role: Nonvolatile parameter storage accessed during boot and periodic self-test; SPI reads occur at <200 kHz during initialization. Use Value: Enables field-replaceable sensors without recalibration; 1M endurance supports lifetime recalibration cycles across device service life.	Use Scenario: Holding user-configurable therapy parameters (e.g., infusion rate limits, alarm thresholds) in battery-powered insulin pumps. IC Role / Device Role / Timing Role: Secure, low-power configuration store; write operations occur only during setup mode with WP asserted. Use Value: 500 nA standby current extends battery life; hardware WP prevents runtime corruption during ESD events or software faults.
PLC Firmware Patch Storage	Automotive Body Control Module Settings
Use Scenario: Hosting hot-fix patches for ladder logic execution engines in DIN-rail mounted PLCs. IC Role / Device Role / Timing Role: Field-upgradable code repository; accessed via isolated SPI bus during maintenance windows. Use Value: 2 MHz SPI speed enables sub-second patch loading; 32-byte page writes minimize bus occupancy during critical control cycles.	Use Scenario: Retaining seat/mirror position memory and lighting profiles across ignition cycles in entry-level BCMs. IC Role / Device Role / Timing Role: Persistent settings store; writes triggered by user input with HOLD used to defer updates until idle bus periods. Use Value: −40°C to +85°C rating ensures operation in under-hood environments; 200-year retention avoids memory degradation over vehicle lifetime.

Industrial Sensor Calibration

Medical Device Configuration

Use Scenario: Storing factory-calibrated sensor offset/gain coefficients and linearization tables in portable gas analyzers.

IC Role / Device Role / Timing Role: Nonvolatile parameter storage accessed during boot and periodic self-test; SPI reads occur at <200 kHz during initialization.

Use Value: Enables field-replaceable sensors without recalibration; 1M endurance supports lifetime recalibration cycles across device service life.

Use Scenario: Holding user-configurable therapy parameters (e.g., infusion rate limits, alarm thresholds) in battery-powered insulin pumps.

IC Role / Device Role / Timing Role: Secure, low-power configuration store; write operations occur only during setup mode with WP asserted.

Use Value: 500 nA standby current extends battery life; hardware WP prevents runtime corruption during ESD events or software faults.

PLC Firmware Patch Storage

Automotive Body Control Module Settings

Use Scenario: Hosting hot-fix patches for ladder logic execution engines in DIN-rail mounted PLCs.

IC Role / Device Role / Timing Role: Field-upgradable code repository; accessed via isolated SPI bus during maintenance windows.

Use Value: 2 MHz SPI speed enables sub-second patch loading; 32-byte page writes minimize bus occupancy during critical control cycles.

Use Scenario: Retaining seat/mirror position memory and lighting profiles across ignition cycles in entry-level BCMs.

IC Role / Device Role / Timing Role: Persistent settings store; writes triggered by user input with HOLD used to defer updates until idle bus periods.

Use Value: −40°C to +85°C rating ensures operation in under-hood environments; 200-year retention avoids memory degradation over vehicle lifetime.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
25AA320-I/ST	1.8–5.5 V supply range; 1 MHz max clock; identical pinout and instruction set	Better suited for mixed-voltage systems with 1.8 V MCUs; lower speed acceptable for infrequent config storage	Choose when system V_CC may dip below 2.5 V or when 1 MHz SPI suffices
25LC320T-I/ST	Identical electrical specs and pinout; supplied in tape-and-reel (T suffix) instead of tube	Same functional behavior; optimized for automated SMT assembly rather than manual prototyping	Choose for volume production with pick-and-place; no design or layout impact

Compared with 25LC320X-I/ST, the 25AA320-I/ST offers wider V_CC flexibility at reduced speed, while the 25LC320T-I/ST differs only in packaging format - both retain identical timing, endurance, and protection features for drop-in replacement in compatible layouts.

Availability

25LC320X-I/ST is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and automotive body electronics requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for 25LC320X-I/ST 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, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25LC320X-I/ST belongs to Microchip's SPI serial EEPROM product line, designed specifically for reliable, low-power nonvolatile storage in space-constrained industrial and automotive applications where write-protection integrity and long-term data retention are critical.

FAQ

What is the supply voltage range supported by the 25LC320X-I/ST?

The 25LC320X-I/ST operates from 2.5 V to 5.5 V DC. This range is specified for industrial temperature operation (−40°C to +85°C) and enables direct interfacing with 3.3 V and 5 V microcontrollers without level shifting. Operation below 2.5 V is not guaranteed and may result in unreliable write cycles or STATUS register reads.

Does the 25LC320X-I/ST support page writes, and what is the maximum page size?

Yes, the 25LC320X-I/ST supports page writes with a maximum size of 32 bytes. Page boundaries are aligned to 32-byte intervals (e.g., 0x0000–0x001F). Attempting to cross a page boundary during a single write sequence causes the internal address counter to roll over, overwriting data at the start of the page - proper address management is required in firmware.

How does the HOLD pin function during an active SPI transaction on the 25LC320X-I/ST?

The HOLD pin on the 25LC320X-I/ST pauses an ongoing SPI transaction when pulled low while SCK is low. During HOLD, SI, SCK, and SO enter high-impedance states and ignore input transitions except CS. Resuming requires bringing HOLD high while SCK remains low; the transaction continues from the exact bit position where it was paused.

What write protection mechanisms are implemented in the 25LC320X-I/ST?

The 25LC320X-I/ST implements dual-layer write protection: (1) software-controlled block protection (BP0/BP1 bits) enabling 0%, 25%, 50%, or 100% array lockdown, and (2) hardware write protection via the WP pin when WPEN = 1 in the STATUS register. Both mechanisms independently guard against unintended writes to memory or STATUS bits.

Is the 25LC320X-I/ST pin-compatible with other variants in the 25XX320 family?

Yes, the 25LC320X-I/ST shares identical 8-pin TSSOP (ST) pinout with 25AA320X-I/ST and 25C320X-I/ST. All three variants use the same CS/SO/WP/V_SS/SI/SCK/HOLD/V_CC assignment. However, voltage ranges and max clock frequencies differ - substituting requires verifying V_CC and timing compliance in the target application.

25LC320X-I/ST Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 8-TSSOP (0.173", 4.40mm Width)

Packaging:: Tube

Product Status:: Active

Programmable:: Not Verified

Memory Type:: Non-Volatile

Memory Format:: EEPROM

Technology:: EEPROM

Memory Size:: 32Kbit

Memory Organization:: 4K x 8

Memory Interface:: SPI

Clock Frequency:: 2 MHz

Write Cycle Time - Word, Page:: 5ms

Access Time:: -

Voltage - Supply:: 2.5V ~ 5.5V

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-TSSOP

25LC320X-I/ST FAQ

1.How can I place an order for 25LC320X-I/ST through Aetrix?

Please submit a Request for Quotation (RFQ) for 25LC320X-I/ST on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 25LC320X-I/ST reliable?

The price and inventory of 25LC320X-I/ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 25LC320X-I/ST is usually 5 days.

3.What payment methods are accepted for 25LC320X-I/ST?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC320X-I/ST transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 25LC320X-I/ST?

25LC320X-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 25LC320X-I/ST order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 25LC320X-I/ST?

For technical support, including 25LC320X-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC320X-I/ST requirements.

6.How does Aetrix verify that 25LC320X-I/ST is sourced from the original manufacturer or authorized distributors?

All 25LC320X-I/ST products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 25LC320X-I/ST meets industry standards.

7.What is the process for return or replacement of 25LC320X-I/ST?

All 25LC320X-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25LC320X-I/ST, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 25LC320X-I/ST part is unused and in its original packaging.

Return procedure for 25LC320X-I/ST:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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