My Inquiry
My Account
Microchip Technology AT25640B-XHL-B
- Part No.:
- AT25640B-XHL-B
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
AT25640B-XHL-B.pdf
- Description:
- IC EEPROM 64KBIT SPI 8TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:600
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AT25640B-XHL-B from Microchip Technology (formerly Atmel) is a 64Kb SPI Serial EEPROM organized as 8,192 words × 8 bits, operating from 1.8V to 5.5V with 20MHz max clock rate at 5V, 32-byte page write capability, and hardware/software write protection via WP pin and status register. It serves as nonvolatile configuration storage in industrial controllers, power supply monitors, and embedded sensor nodes requiring long-term data retention.
For engineers reviewing the AT25640B-XHL-B datasheet, AT25640B-XHL-B pinout, AT25640B-XHL-B application, or AT25640B-XHL-B equivalent, key selection criteria include its industrial temperature range (−40°C to +85°C), 1,000,000 write endurance, 100-year data retention, TSSOP-8 package compatibility, and support for SPI Modes 0 and 3 with HOLD/CS-controlled serial suspension.
Technical Context
The AT25640B-XHL-B implements a synchronous SPI slave interface with dedicated SI (input), SO (output), SCK (clock), CS (chip select), WP (write protect), and HOLD (communication suspend) pins. Its internal architecture includes an 8-bit instruction register, address decoder, status register with BP0/BP1 block protection bits and WPEN control, and self-timed write logic eliminating external erase cycles.
It supports four levels of block write protection (none, 1/4, 1/2, or full array), configurable via WRSR instruction, and provides dual-layer data security: software-enabled write enable latch (WREN/WRDI) plus hardware-level inhibition when WP is low and WPEN = 1. All operations are MSB-first, with automatic address increment during sequential reads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 64Kb (8,192 × 8-bit words) - sufficient for firmware parameter tables, calibration data, or device ID storage in compact systems. |
| Supply Voltage Range | 1.8V to 5.5V - enables direct interfacing with 1.8V, 3.3V, and 5V microcontrollers without level shifting. |
| Max Clock Frequency | 20MHz at VCC = 5V - supports high-speed configuration loading in time-critical boot sequences. |
| Page Write Size | 32 bytes - balances programming speed and granularity for efficient partial updates without full-array erasure. |
| Write Cycle Time | 5ms maximum - defines worst-case latency for persistent state saves; critical for real-time logging applications. |
| Endurance & Retention | 1,000,000 write cycles / 100 years data retention - ensures reliability across product lifetime in field-deployed equipment. |
| Operating Temperature | −40°C to +85°C - qualified for industrial environments including factory automation and outdoor metering. |
Pinout & Package
AT25640B-XHL-B is packaged in an 8-lead TSSOP (8X) with 4.40mm body width, RoHS-compliant NiPdAu lead finish, and industrial-grade thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable signal; must be held low during entire SPI transaction; high-impedance SO output when high. |
| SCK | Serial Clock | Input-only master-generated clock; timing governs SI sampling and SO output validity per SPI Mode 0/3. |
| SI | Serial Data Input | Accepts opcodes (WREN, WRITE, RDSR, etc.), addresses, and data; MSB-first, sampled on SCK rising edge (Mode 0). |
| SO | Serial Data Output | Drives read data and status register contents; high-impedance when CS high or during HOLD assertion. |
| WP | Write Protect | Hardware lock: when low and WPEN=1, blocks all status register writes and protected memory writes. |
| HOLD | Communication Suspend | Pauses ongoing SPI transfer without resetting sequence; requires SCK low during assertion/deassertion. |
| VCC | Power Supply | 1.8V–5.5V input; powers internal logic and memory array; decoupling capacitor required per layout guidelines. |
| GND | Ground Reference | Return path for VCC and all I/O signals; must be low-impedance connection to minimize noise coupling. |
Key Features
| Feature | Design Value |
|---|---|
| SPI Mode 0 & 3 Support | Interoperates with diverse microcontrollers (e.g., AVR, STM32, PIC) without protocol translation hardware. |
| Block Write Protection | Configurable 0%, 25%, 50%, or 100% memory locking via status register-prevents accidental corruption of critical firmware parameters. |
| Hardware + Software Write Protection | Combines WP pin hard-lock with WREN/WRDI instructions-enables layered security for production programming vs. field updates. |
| Self-Timed Write Cycle | No external timing control needed; internal logic manages erase/write/verify-simplifies host firmware design. |
| HOLD Pin Functionality | Allows multi-master arbitration or CPU context switching without losing SPI state-essential in resource-constrained MCUs. |
Applications
| Industrial Sensor Calibration | Power Supply Configuration Storage |
|---|---|
Use Scenario: Storing temperature-compensated offset/gain coefficients for analog sensor front-ends in programmable logic controllers. IC Role / Device Role / Timing Role: Nonvolatile parameter repository accessed during system startup and periodic recalibration routines. Use Value: Enables field-upgradable calibration without firmware reflash; 100-year retention ensures accuracy over equipment lifetime. |
Use Scenario: Holding voltage/current limit settings, soft-start profiles, and fault recovery thresholds in digitally controlled AC-DC converters. IC Role / Device Role / Timing Role: Persistent configuration store queried at power-on reset and updated only during maintenance mode. Use Value: Prevents loss of safety-critical settings after brownout; block protection secures factory defaults from runtime overwrite. |
| Medical Device Settings Backup | Smart Meter Firmware Parameter Tables |
Use Scenario: Archiving user-adjustable therapy parameters (e.g., infusion rate, alarm thresholds) in portable diagnostic equipment. IC Role / Device Role / Timing Role: Secure, low-power data vault accessed via SPI during setup and diagnostics. Use Value: Meets IEC 62304 data integrity requirements; WP/HOLD pins support safe concurrent operation with USB host interface. |
Use Scenario: Storing tariff schedules, communication keys, and metrology calibration constants in ANSI C12.22-compliant electricity meters. IC Role / Device Role / Timing Role: Tamper-resistant configuration memory isolated from main application processor via dedicated SPI bus. Use Value: Hardware write protection prevents unauthorized modification of billing parameters; 1M-cycle endurance supports daily firmware patching. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SPI EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| M95640-DRMN6TP/K | 64Kb SPI EEPROM, 2.5–5.5V supply, 20MHz max, TSSOP-8, but lacks HOLD pin and has no hardware WP pin-relies solely on software protection. | Not suitable where hardware suspend or physical write lock is required; limited in multi-master or safety-critical contexts. | Select when cost sensitivity outweighs need for HOLD/WP; verify host firmware can manage all protection in software. |
| 25AA640A-I/ST | 64Kb SPI EEPROM, 1.8–5.5V, 10MHz max, TSSOP-8, includes WP pin but no HOLD pin; supports only SPI Mode 0. | Lower clock rate limits throughput in high-bandwidth logging; absence of HOLD complicates interrupt-driven designs. | Choose for legacy 10MHz systems or where HOLD functionality is unused; confirm timing margins meet application latency budget. |
Compared with M95640-DRMN6TP/K and 25AA640A-I/ST, AT25640B-XHL-B uniquely delivers both HOLD and WP pins within the same TSSOP-8 footprint, enabling robust hardware-managed suspend and dual-layer write security-critical for industrial and medical applications demanding deterministic behavior and tamper resistance.
Availability
AT25640B-XHL-B is available at Aetrix Electronics and suitable for industrial automation, smart energy metering, and medical diagnostics requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for AT25640B-XHL-B 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 acquired Atmel in 2016 and maintains its legacy serial EEPROM portfolio with full technical documentation, longevity commitment, and global manufacturing oversight.
The AT25640B-XHL-B belongs to Microchip's industrial-grade SPI Serial EEPROM family, designed specifically for reliable nonvolatile storage in space-constrained, low-power embedded systems where data integrity and long-term retention are mandatory.
FAQ
What is the operating voltage range for AT25640B-XHL-B?
The AT25640B-XHL-B operates from 1.8V to 5.5V, supporting direct integration with 1.8V, 3.3V, and 5V logic families. This wide range eliminates level-shifting requirements in mixed-voltage systems and ensures compatibility with battery-powered devices down to 1.8V nominal supply.
Does AT25640B-XHL-B support SPI Mode 3 in addition to Mode 0?
Yes, AT25640B-XHL-B supports both SPI Mode 0 (CPOL = 0, CPHA = 0) and Mode 3 (CPOL = 1, CPHA = 1), as confirmed in the official datasheet. This dual-mode capability allows seamless interoperability with microcontrollers such as certain STM32 and NXP Kinetis variants that default to Mode 3.
How does the HOLD pin function during an active SPI transaction in AT25640B-XHL-B?
In AT25640B-XHL-B, the HOLD pin suspends serial communication without resetting the command sequence: when asserted low while SCK is low, it places SO in high-impedance and ignores SI inputs; deassertion (HOLD high while SCK low) resumes exactly where the transaction left off-enabling precise multi-tasking in MCU firmware.
What memory organization does AT25640B-XHL-B use, and how is addressing structured?
AT25640B-XHL-B organizes its 64Kb as 8,192 words × 8 bits. Addressing uses A12–A0 (13 bits), with A15–A13 as don't-care bits. During READ/WRITE, the 13-bit address is transmitted MSB-first after the opcode, enabling linear access across the full memory space with automatic rollover on boundary crossing.
Can AT25640B-XHL-B be used in automotive applications?
No-AT25640B-XHL-B is specified for industrial temperature range (−40°C to +85°C) and is not qualified for automotive AEC-Q100 stress testing. Microchip explicitly states its serial EEPROMs are not intended for automotive safety-critical or life-support applications; use automotive-grade alternatives like the 25LC640A for such deployments.
AT25640B-XHL-B 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:
- 64Kbit
- Memory Organization:
- 8K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 20 MHz
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
AT25640B-XHL-B FAQ
1.How can I place an order for AT25640B-XHL-B through Aetrix?
Please submit a Request for Quotation (RFQ) for AT25640B-XHL-B 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 AT25640B-XHL-B reliable?
The price and inventory of AT25640B-XHL-B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT25640B-XHL-B is usually 5 days.
3.What payment methods are accepted for AT25640B-XHL-B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT25640B-XHL-B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT25640B-XHL-B?
AT25640B-XHL-B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT25640B-XHL-B 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 AT25640B-XHL-B?
For technical support, including AT25640B-XHL-B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT25640B-XHL-B requirements.
6.How does Aetrix verify that AT25640B-XHL-B is sourced from the original manufacturer or authorized distributors?
All AT25640B-XHL-B 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 AT25640B-XHL-B meets industry standards.
7.What is the process for return or replacement of AT25640B-XHL-B?
All AT25640B-XHL-B units undergo pre-shipment inspection (PSI). If there is an issue with AT25640B-XHL-B, 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 AT25640B-XHL-B part is unused and in its original packaging.
Return procedure for AT25640B-XHL-B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT25640B-XHL-B Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
