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

Microchip Technology 25LC320XT-I/ST

Name: 25LC320XT-I/ST
Brand: Microchip Technology
SKU: 25LC320XT-I/ST
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 25LC320XT-I/ST

Manufacturer:: Microchip Technology

Category:: Memory

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

Datasheet:: 25LC320XT-I/ST.pdf

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

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Product details

Overview

25LC320XT-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. Used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 25LC320XT-I/ST datasheet, 25LC320XT-I/ST pinout, 25LC320XT-I/ST application, or 25LC320XT-I/ST equivalent, key selection criteria include V_CC compatibility (2.5–5.5 V), SPI timing compliance (t_CSH, t_HOLD), endurance (1 million E/W cycles), and TSSOP-8 mechanical fit in space-constrained PCBs.

Technical Context

This device implements a standard SPI Mode 0,0 interface with separate SI/SO lines, CS-controlled selection, and dedicated HOLD and WP pins for deterministic bus arbitration and hardware-level write security. Its internal architecture includes an 8-bit instruction register, auto-incrementing address pointer for sequential reads, and status register (WIP, WEL, BP0/BP1, WPEN) accessible during active writes.

Write operations require explicit WREN instruction before WRITE or WRSR, and CS must be deasserted after final data bit to initiate self-timed 5 ms internal write cycle. Block protection supports four configurations (none, upper 1/4, upper 1/2, or full array), configurable via nonvolatile BP bits in the STATUS register.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory Size	32 Kbit (4096 × 8 bits); sufficient for storing bootloader configs, device IDs, or sensor calibration tables in compact systems.
Interface	SPI Mode 0,0 (CPOL=0, CPHA=0); compatible with PIC, AVR, ARM Cortex-M, and most MCU SPI peripherals without software translation.
Max Clock Frequency	2 MHz at V_CC = 2.5–5.5 V; enables ~256 KB/s effective read throughput and supports real-time parameter updates in industrial control loops.
Write Cycle Time	5 ms maximum; defines minimum interval between successive page writes and impacts firmware update latency.
Endurance & Retention	1 million erase/write cycles and >200 years data retention; validated for long-life deployment in unattended equipment like smart meters and remote sensors.
Supply Current	500 μA typical read current, 3 mA max write current, 500 nA standby; enables battery-backed operation in low-power IoT nodes.
Temperature Range	Industrial: −40°C to +85°C; qualified for use in automotive body electronics, industrial PLC I/O modules, and outdoor environmental monitors.

Pinout & Package

8-pin Plastic TSSOP (4.4 mm body width, ST suffix), RoHS-compliant, surface-mount package with 0.65 mm pitch. Pin 1 marked by notch or dot; pin 1 is CS.

Pin/Terminal	Circuit Role	Design Meaning
CS (Pin 1)	Chip Select Input	Active-low enable: pulls device out of standby; rising edge after write sequence triggers internal write cycle; high-Z SO when deasserted.
SO (Pin 2)	Serial Data Output	Tri-state output; data shifted out on SCK falling edge; enters high-impedance state when CS high or HOLD low.
WP (Pin 3)	Write-Protect Input	Hardware lock: disables STATUS register writes when WPEN=1 and WP=low; no effect on memory writes unless BP bits are set.
V_SS (Pin 4)	Ground Reference	Primary return path for all digital and internal HV generator currents; requires low-impedance connection to minimize noise coupling into EEPROM array.
SI (Pin 5)	Serial Data Input	Latches instruction/address/data on SCK rising edge; accepts MSB-first SPI frames including READ, WRITE, RDSR, WRSR, WREN, WRDI.
SCK (Pin 6)	Serial Clock Input	Master-generated clock; timing-critical path with min/max t_LO/t_HI (150–475 ns) and rise/fall time ≤2 μs per AC specs.
HOLD (Pin 7)	Communication Pause Input	Active-low suspend: freezes SPI state machine without resetting sequence; requires SCK low before assertion and release; tri-states SO immediately.
V_CC (Pin 8)	Supply Voltage	2.5–5.5 V operation; internal charge pump generates programming voltage; decoupling capacitor (0.1 μF) required within 10 mm of pin.

Key Features

Feature	Design Value
Page Write Capability	32-byte page boundary alignment ensures efficient bulk writes without crossing page boundaries-critical for logging timestamped sensor data streams.
Hardware Write Protection	WP pin + WPEN bit enables field-programmable, tamper-resistant lock of STATUS register and memory blocks-used in certified medical device configuration locks.
HOLD Functionality	Enables deterministic pause/resume of ongoing SPI transfers during MCU interrupt servicing-eliminates need for transaction retransmission in real-time control systems.
Block Protection Flexibility	BP0/BP1 bits allow selective protection of upper 1/4 (0xC00–0xFFF), upper 1/2 (0x800–0xFFF), or full array-supports secure boot loader + user-configurable parameter partitioning.
Low-Power Operation	500 nA standby current and 500 μA read current at 2.5 V enable multi-year operation on coin-cell batteries in wireless sensor nodes.

Applications

Industrial Sensor Node	Automotive Body Control Module
Use Scenario: Storing calibrated offset/gain values for temperature, pressure, and humidity sensors in factory-floor monitoring units. IC Role / Device Role / Timing Role: Nonvolatile configuration storage accessed at power-up and during field recalibration; SPI read completes in <100 μs per byte. Use Value: Eliminates manual trim potentiometers and enables automated calibration traceability across production batches.	Use Scenario: Retaining seat position memory, mirror angle settings, and lighting preferences in vehicle door modules. IC Role / Device Role / Timing Role: SPI EEPROM interfaced directly to 8-bit automotive MCU; withstands 125°C ambient during engine-off soak testing. Use Value: Survives repeated thermal cycling and meets AEC-Q100 Grade 2 requirements for passenger compartment electronics.
Medical Infusion Pump	Smart Energy Meter
Use Scenario: Logging dose history, alarm events, and maintenance timestamps with tamper-evident write protection. IC Role / Device Role / Timing Role: Secure parameter storage with WP-enabled STATUS register lock; BP1/BP0 protect critical therapy parameters. Use Value: Supports FDA 21 CFR Part 11 audit trail requirements via deterministic, nonvolatile event logging.	Use Scenario: Storing tariff schedules, meter ID, firmware version, and accumulated kWh readings in utility-grade electricity meters. IC Role / Device Role / Timing Role: High-reliability data logger with 1M-cycle endurance; operates continuously at 85°C inside sealed meter enclosures. Use Value: Guarantees 10+ year field life under constant thermal stress and frequent write cycles during billing intervals.

Industrial Sensor Node

Automotive Body Control Module

Use Scenario: Storing calibrated offset/gain values for temperature, pressure, and humidity sensors in factory-floor monitoring units.

IC Role / Device Role / Timing Role: Nonvolatile configuration storage accessed at power-up and during field recalibration; SPI read completes in <100 μs per byte.

Use Value: Eliminates manual trim potentiometers and enables automated calibration traceability across production batches.

Use Scenario: Retaining seat position memory, mirror angle settings, and lighting preferences in vehicle door modules.

IC Role / Device Role / Timing Role: SPI EEPROM interfaced directly to 8-bit automotive MCU; withstands 125°C ambient during engine-off soak testing.

Use Value: Survives repeated thermal cycling and meets AEC-Q100 Grade 2 requirements for passenger compartment electronics.

Medical Infusion Pump

Smart Energy Meter

Use Scenario: Logging dose history, alarm events, and maintenance timestamps with tamper-evident write protection.

IC Role / Device Role / Timing Role: Secure parameter storage with WP-enabled STATUS register lock; BP1/BP0 protect critical therapy parameters.

Use Value: Supports FDA 21 CFR Part 11 audit trail requirements via deterministic, nonvolatile event logging.

Use Scenario: Storing tariff schedules, meter ID, firmware version, and accumulated kWh readings in utility-grade electricity meters.

IC Role / Device Role / Timing Role: High-reliability data logger with 1M-cycle endurance; operates continuously at 85°C inside sealed meter enclosures.

Use Value: Guarantees 10+ year field life under constant thermal stress and frequent write cycles during billing intervals.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
25AA320XT-I/ST	V_CC range 1.8–5.5 V; 1 MHz max clock; same 8-pin TSSOP package and pinout.	Better suited for 1.8 V logic systems (e.g., ultra-low-power MCUs); lower speed tolerance reduces EMI in noise-sensitive analog sections.	Select when system V_CC drops below 2.5 V or when 1 MHz SPI timing simplifies layout routing.
AT25DF321A-MAU-T	32 Mbit density, quad SPI interface, 85 MHz clock; SOIC-8 package; no HOLD or WP pins.	Targeted at firmware code storage-not parameter/configuration storage; lacks hardware write protection and interrupt-safe HOLD.	Choose only for high-speed code shadowing; not a functional substitute for configuration EEPROM due to missing WP/HOLD and different command set.

Compared with 25AA320XT-I/ST and AT25DF321A-MAU-T, the 25LC320XT-I/ST provides optimal balance of industrial temperature support, hardware write protection, HOLD functionality, and proven 1M-cycle reliability for configuration-critical embedded systems-whereas alternatives trade off security, determinism, or qualification scope.

Availability

25LC320XT-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body control modules, medical infusion pumps, and smart energy meters requiring stable component supply over extended product lifecycles.

Supply support for 25LC320XT-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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25LC320XT-I/ST belongs to Microchip's legacy SPI serial EEPROM product line, designed specifically for reliable, low-power, pin-efficient nonvolatile storage in cost-sensitive industrial and automotive applications.

FAQ

What is the operating voltage range for the 25LC320XT-I/ST?

The 25LC320XT-I/ST operates from 2.5 V to 5.5 V DC. This range supports common industrial logic levels (3.3 V) and legacy 5 V systems while excluding sub-2.5 V operation-unlike the 25AA320 variant. Operation outside this range may cause unreliable writes or premature endurance wear.

Does the 25LC320XT-I/ST support SPI Mode 1,1 or only Mode 0,0?

The 25LC320XT-I/ST supports SPI Mode 0,0 exclusively (CPOL = 0, CPHA = 0). Data is sampled on the rising edge of SCK and output changes on the falling edge. Attempting Mode 1,1 will result in misaligned bit sampling and corrupted reads/writes.

How does the HOLD pin function during an active SPI transaction on the 25LC320XT-I/ST?

When pulled low while SCK is low, the HOLD pin pauses the 25LC320XT-I/ST mid-transaction: SI, SO, and SCK enter high-impedance states, and internal sequencing freezes. Resuming requires bringing HOLD high while SCK remains low-ensuring deterministic restart without reinitialization or data loss.

Can the 25LC320XT-I/ST be used in automotive under-hood applications?

No-the 25LC320XT-I/ST is rated for Industrial temperature range (−40°C to +85°C), not Automotive (−40°C to +125°C). For under-hood use, Microchip specifies the 25LC320-E/ST variant; substituting the -I/ST version risks parametric failure above 85°C ambient.

What happens to the write enable latch after a successful WRITE instruction on the 25LC320XT-I/ST?

After a successful WRITE instruction completes-including CS deassertion to trigger the internal 5 ms write cycle-the write enable latch (WEL) is automatically reset to '0'. Subsequent writes therefore require reissuing the WREN instruction, preventing accidental overwrites during power glitches or software faults.

25LC320XT-I/ST Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

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

Packaging:: Tape & Reel (TR)

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

25LC320XT-I/ST FAQ

1.How can I place an order for 25LC320XT-I/ST through Aetrix?

Please submit a Request for Quotation (RFQ) for 25LC320XT-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 25LC320XT-I/ST reliable?

The price and inventory of 25LC320XT-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 25LC320XT-I/ST is usually 5 days.

3.What payment methods are accepted for 25LC320XT-I/ST?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 25LC320XT-I/ST transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 25LC320XT-I/ST?

25LC320XT-I/ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 25LC320XT-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 25LC320XT-I/ST?

For technical support, including 25LC320XT-I/ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 25LC320XT-I/ST requirements.

6.How does Aetrix verify that 25LC320XT-I/ST is sourced from the original manufacturer or authorized distributors?

All 25LC320XT-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 25LC320XT-I/ST meets industry standards.

7.What is the process for return or replacement of 25LC320XT-I/ST?

All 25LC320XT-I/ST units undergo pre-shipment inspection (PSI). If there is an issue with 25LC320XT-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 25LC320XT-I/ST part is unused and in its original packaging.

Return procedure for 25LC320XT-I/ST:

1.Submit a request within 90 days.

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

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