My Inquiry
My Account
Microchip Technology 23A640-I/SN
- Part No.:
- 23A640-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
23A640-I/SN.pdf
- Description:
- IC SRAM 64KBIT SPI 20MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,130
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
23A640-I/SN from Microchip Technology is a 64 Kbit (8192 × 8) low-voltage SPI Serial SRAM with 1.5–1.95 V supply, 20 MHz max clock, 32-byte page size, and HOLD pin for interrupt-safe bus suspension. It operates in Industrial temperature range (−40°C to +85°C) and supports byte/page/sequential read/write modes for embedded microcontroller data buffering.
For engineers reviewing the 23A640-I/SN datasheet, 23A640-I/SN pinout, 23A640-I/SN application, or 23A640-I/SN equivalent, key selection criteria include its 1.8 V operation, 4 µA max standby current at +85°C, SPI-compatible interface with separate SI/SO lines, and HOLD functionality enabling deterministic host interrupt handling without sequence restart.
Technical Context
The 23A640-I/SN implements a synchronous serial interface compliant with SPI Mode 0 (CPOL = 0, CPHA = 0), using rising-edge sampling on SI and falling-edge output on SO. Its internal 8-bit instruction register accepts READ (0x03), WRITE (0x02), RDSR (0x05), and WRSR (0x01) commands with MSB-first transmission.
Operating mode is controlled via STATUS register bits 7–6: Byte (00, default), Page (10), or Sequential (01). The HOLD pin suspends active transfers while preserving internal address state, requiring SCK-low assertion and STATUS bit 0 cleared to enable - critical for real-time systems managing concurrent peripherals.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8192 × 8-bit organization), providing compact volatile storage for firmware variables or sensor buffers. |
| Supply Voltage | 1.5–1.95 V - enables direct interfacing with 1.8 V logic domains without level shifting. |
| Max Clock Frequency | 20 MHz at VCC = 1.8 V - supports high-throughput data logging at up to 2.5 MB/s effective rate. |
| Standby Current | ≤4 µA at +85°C - minimizes power in sleep states for battery-powered IoT endpoints. |
| Page Size | 32 bytes - balances burst efficiency and write granularity for firmware update staging. |
| Temperature Range | Industrial (−40°C to +85°C) - qualified for industrial control, medical diagnostics, and automotive body electronics. |
| HOLD Function | Dedicated active-low HOLD pin with 10 ns setup/hold timing - allows deterministic pause/resume of ongoing SPI transfers. |
Pinout & Package
23A640-I/SN is packaged in 8-lead SOIC (SN) per JEDEC MS-012, 3.90 mm body width, with 1.27 mm pitch. Pin 1 is CS (Chip Select), pin 2 is SO (Serial Output), pin 4 is VSS (Ground), pin 5 is SI (Serial Input), pin 6 is SCK (Serial Clock), pin 7 is HOLD (Hold Input), and pin 8 is VCC (Supply Voltage). Pin 3 is NC (No Connect).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select Input | Active-low enable: drives device into Standby (SO high-Z) when high; required low-to-high transition initiates all operations. |
| SO | Serial Data Output | Tri-state open-drain output updated after SCK falling edge; shares bus with other SPI slaves when CS high. |
| VSS | Ground Reference | Primary return path for all I/O and core logic; must be low-impedance connection to system ground plane. |
| SI | Serial Data Input | Latches instruction/address/data on SCK rising edge; requires clean 1.8 V logic levels with ≤0.2×VCC low threshold. |
| SCK | Serial Clock Input | Synchronizes all data transfers; rise/fall times ≤2 µs; duty cycle 40–60% required for reliable timing margins. |
| HOLD | Hold Input | Pauses active SPI transfer without resetting internal address pointer; must be asserted while SCK is low to take effect. |
| VCC | Supply Voltage | 1.5–1.95 V regulated input; decoupling capacitor (0.1 µF ceramic) required within 5 mm of pin 8 for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Low-Voltage Operation | 1.5–1.95 V supply enables integration into 1.8 V FPGA/microcontroller systems without voltage translation. |
| Page Write Mode | 32-byte page writes reduce SPI transaction overhead by 31× vs. byte writes for contiguous data blocks. |
| HOLD Pin Functionality | Preserves internal address state during host interrupt servicing - eliminates need for retransmission or software tracking. |
| Industrial Temp Rating | Guaranteed operation from −40°C to +85°C supports deployment in uncontrolled environments like factory floors or outdoor gateways. |
| Pb-Free & RoHS Compliant | Meets EU Directive 2011/65/EU and halogen-free requirements for environmentally constrained applications. |
Applications
| Industrial Data Logger | Medical Sensor Hub |
|---|---|
Use Scenario: Captures timestamped analog sensor readings (temperature, pressure) at 1 kHz for local buffering before USB/UART upload. IC Role / Device Role / Timing Role: Volatile buffer between ADC controller and host MCU; absorbs burst writes during communication gaps. Use Value: 32-byte page writes minimize SPI overhead; 4 µA standby current extends battery life in maintenance-free deployments. |
Use Scenario: Aggregates ECG, SpO₂, and respiration signals from multiple transducers in portable diagnostic equipment. IC Role / Device Role / Timing Role: Real-time FIFO for sensor fusion preprocessing; HOLD pin ensures uninterrupted acquisition during display refresh interrupts. Use Value: 1.8 V operation matches low-power MCU I/O; 20 MHz clock supports 16-bit sample streaming at >100 kSPS aggregate rate. |
| Automotive Body Control Module | Smart Meter Communication Interface |
Use Scenario: Stores door lock status, window position, and mirror calibration settings across ignition cycles in entry-level vehicles. IC Role / Device Role / Timing Role: Non-retentive configuration memory accessed during boot and runtime; powered from always-on 1.8 V rail. Use Value: Industrial temp rating covers under-dash thermal zones; HOLD function prevents corruption during CAN bus arbitration delays. |
Use Scenario: Buffers encrypted firmware updates and tariff schedule tables received over PLC or RF mesh networks. IC Role / Device Role / Timing Role: Secure staging area for authenticated code before flash programming; sequential read mode enables fast checksum verification. Use Value: 8192 × 8-bit capacity holds full AES-128 keys + 2 KB update payload; 1.5 V min supply tolerates brown-out conditions during grid fluctuations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SPI Serial SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 23K640-I/SN | Wider VCC range (2.7–3.6 V); higher standby current (1 µA typical at +85°C); same 64 Kbit density and pinout. | Requires 3.3 V domain; less suitable for ultra-low-power battery systems but offers better noise margin in noisy industrial settings. | Select 23K640-I/SN when system already uses 3.3 V logic and higher immunity to supply ripple is needed. |
| FM25V05-G | F-RAM technology; unlimited endurance (>10¹⁴ cycles); 2.7–3.6 V supply; 40 MHz max clock; different pinout (SOIC-8 but CS/SO/SI/SCK assignments differ). | No write delay; eliminates wear leveling; suited for high-write-cycle telemetry but incompatible pin-for-pin with 23A640-I/SN. | Choose FM25V05-G only if application demands extreme write endurance and PCB layout can accommodate pin rearrangement. |
Compared with 23K640-I/SN and FM25V05-G, the 23A640-I/SN delivers optimal balance of ultra-low voltage operation, sub-µA standby, and drop-in compatibility with 1.8 V microcontrollers - making it ideal for space-constrained, battery-sensitive designs where F-RAM cost or 3.3 V supply is prohibitive.
Availability
23A640-I/SN is available at Aetrix Electronics and suitable for industrial data loggers, portable medical sensors, automotive body controllers, and smart meter communication interfaces requiring stable component supply across extended product lifecycles.
Supply support for 23A640-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, mixed-signal, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 23A640 belongs to Microchip's SPI Serial SRAM product line, designed specifically for low-voltage, low-power embedded systems needing reliable, pin-efficient volatile memory with deterministic interrupt handling via HOLD functionality.
FAQ
What is the minimum supply voltage required for reliable operation of the 23A640-I/SN?
The 23A640-I/SN has a specified minimum supply voltage of 1.5 V per DC Characteristics Table D001. Below this threshold, data retention and read/write functionality are not guaranteed. At 1.5 V, maximum clock frequency is reduced to 10 MHz, and standby current remains ≤4 µA at +85°C - verified across production lots per DS22126E-page 2.
Does the 23A640-I/SN support true SPI Mode 0 (CPOL=0, CPHA=0)?
Yes, the 23A640-I/SN fully supports SPI Mode 0: data is sampled on the rising edge of SCK (CPHA=0) and clock idles low (CPOL=0). This is confirmed in Section 2.1 and Figure 2-1 through 2-8 of DS22126E, where SI latching occurs on SCK rising edge and SO output changes after SCK falling edge - matching standard Mode 0 timing.
How does the HOLD pin behave when asserted during an active write sequence?
When HOLD is pulled low during an active write, the 23A640-I/SN immediately pauses the transfer, tri-states SO, and freezes the internal address counter. Upon returning HOLD high (while SCK is low), the device resumes exactly where it left off - no data loss or address reset occurs. This behavior is documented in Section 2.5 and Figure 1-1 of DS22126E.
Can the 23A640-I/SN be used in automotive under-hood applications?
No - the 23A640-I/SN is rated only for Industrial temperature range (−40°C to +85°C), not Automotive (−40°C to +125°C). For under-hood use, Microchip specifies the 23K640-E/ST variant, which supports +125°C ambient and has different DC characteristics (e.g., VCC = 2.7–3.6 V). Using 23A640-I/SN beyond +85°C risks data corruption and parametric failure.
What is the purpose of the "don't care" bit in the 16-bit address field during READ operations?
In READ instructions, the most significant bit (MSB) of the 16-bit address is marked "don't care" because the 23A640-I/SN's 8192-byte memory map occupies only 13 address bits (0x0000–0x1FFF). The upper 3 bits are ignored, allowing firmware to transmit any value in those positions without affecting memory access - simplifying address generation in resource-constrained MCUs per Section 2.3 of DS22126E.
23A640-I/SN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Memory Type:
- Volatile
- Memory Format:
- SRAM
- Technology:
- SRAM
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 20 MHz
- Write Cycle Time - Word, Page:
- -
- Access Time:
- -
- Voltage - Supply:
- 1.7V ~ 1.95V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
23A640-I/SN FAQ
1.How can I place an order for 23A640-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 23A640-I/SN 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 23A640-I/SN reliable?
The price and inventory of 23A640-I/SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 23A640-I/SN is usually 5 days.
3.What payment methods are accepted for 23A640-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 23A640-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 23A640-I/SN?
23A640-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 23A640-I/SN 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 23A640-I/SN?
For technical support, including 23A640-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 23A640-I/SN requirements.
6.How does Aetrix verify that 23A640-I/SN is sourced from the original manufacturer or authorized distributors?
All 23A640-I/SN 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 23A640-I/SN meets industry standards.
7.What is the process for return or replacement of 23A640-I/SN?
All 23A640-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 23A640-I/SN, 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 23A640-I/SN part is unused and in its original packaging.
Return procedure for 23A640-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
23A640-I/SN 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…
