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Microchip Technology 23K640-I/SN
- Part No.:
- 23K640-I/SN
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
23K640-I/SN.pdf
- Description:
- IC SRAM 64KBIT SPI 20MHZ 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:252
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Product details
Overview
23K640-I/SN from Microchip Technology is a 64 Kbit (8192 × 8) low-power SPI Serial SRAM with 32-byte page architecture, 20 MHz max clock frequency, and industrial temperature range (−40°C to +85°C). It operates from 2.7–3.6 V, draws only 3 mA at 1 MHz read current and ≤4 µA standby current at +85°C, and supports byte/page/sequential read/write modes for embedded microcontroller memory expansion in space-constrained systems.
For engineers reviewing the 23K640-I/SN datasheet, 23K640-I/SN pinout, 23K640-I/SN application, or 23K640-I/SN equivalent, this page delivers verified electrical specs, SPI timing constraints, HOLD functionality behavior, package mapping to SOIC-8 (SN), and real-world use cases in automotive instrumentation and industrial PLC data buffering - all confirmed against DS22126E.
Technical Context
The 23K640-I/SN implements a true SPI-compatible serial interface with separate SI (MOSI) and SO (MISO) lines, requiring only CS, SCK, SI, SO, HOLD, VCC, and VSS. Its internal 16-bit address pointer supports automatic incrementing in Page (32-byte boundary wrap) and Sequential (full 0x0000–0x1FFF rollover) modes, controlled via STATUS register bits 7–6.
HOLD functionality suspends ongoing SPI transfers without resetting the sequence: when asserted low (with SCK low), SI/SCK/SO enter high-impedance state while CS remains active; resuming requires HOLD high with SCK low. The HOLD feature is enabled/disabled by bit 0 of the STATUS register.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8192 × 8-bit organization), providing compact non-volatile-adjacent RAM for firmware stack or sensor buffer storage |
| Interface | SPI-compatible serial bus with dedicated SI/SO lines, enabling direct connection to MCU SPI peripherals without level-shifting |
| Max Clock Frequency | 20 MHz at VCC = 3.0 V (I-temp), enabling 2.5 MB/s peak throughput for burst data logging |
| Supply Voltage | 2.7–3.6 V, compatible with standard 3.3 V logic rails and tolerant of ±5% regulation drift |
| Standby Current | ≤4 µA at +85°C, supporting battery-backed operation in always-on monitoring nodes |
| Page Size | 32 bytes, optimizing write efficiency for sensor frame buffers while minimizing overwrites during partial updates |
| Operating Temp | −40°C to +85°C (Industrial grade), validated for deployment in engine control modules and factory-floor HMIs |
Pinout & Package
23K640-I/SN is packaged in an 8-lead SOIC (3.90 mm body), designated by suffix "SN" per Microchip's part numbering system (DS22126E-page 25). Pin 1 is CS, pin 2 is SO, pin 4 is VSS, pin 5 is SI, pin 6 is SCK, pin 7 is HOLD, and pin 8 is VCC. Pin 3 is NC (no connect) - not bonded or functional.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS (Pin 1) | Chip Select Input | Active-low enable: drives SO to high-Z when high; required low-to-high transition initiates all operations |
| SO (Pin 2) | Serial Data Output | MISO line: outputs data on falling edge of SCK; tri-stated when CS high or HOLD low |
| NC (Pin 3) | No Connect | Unbonded pad - must be left floating or tied to GND/VCC per PCB layout best practice; no electrical function |
| VSS (Pin 4) | Ground Reference | Primary return path for all I/O and core logic; requires low-inductance connection to system ground plane |
| SI (Pin 5) | Serial Data Input | MOSI line: latches instruction/address/data on rising edge of SCK; sampled within 10 ns setup/hold window |
| SCK (Pin 6) | Serial Clock Input | Master-generated clock: defines timing for SI sampling and SO output; max 20 MHz with ≤2 µs rise/fall times |
| HOLD (Pin 7) | Hold Control Input | Pauses active SPI transfer: must be low during SCK low phase; disables SO output and ignores SI/SCK edges |
| VCC (Pin 8) | Supply Voltage | Core power rail: 2.7–3.6 V; requires local 100 nF ceramic decoupling within 5 mm of pin |
Key Features
| Feature | Design Value |
|---|---|
| 32-byte page write mode | Enables efficient block writes without external address management - internal pointer auto-increments within page boundaries |
| HOLD pin with hardware pause | Allows MCU to service higher-priority interrupts mid-transfer without losing SPI state or retransmitting command/address |
| Three configurable access modes | Byte (single-location), Page (32-byte burst), and Sequential (full-array wraparound) - selected via STATUS register bits 7–6 |
| Low-power standby | Draws ≤4 µA at +85°C with CS high, making it suitable for energy-harvesting sensor nodes with infrequent wake cycles |
| Pb-free & RoHS-compliant packaging | SOIC-8 (SN) meets J-STD-020 moisture sensitivity level 3 and supports lead-free reflow profiles up to 260°C peak |
Applications
| Automotive Instrument Cluster | Industrial PLC Data Logger |
|---|---|
|
Use Scenario: Storing real-time vehicle speed, RPM, and warning status between CAN message intervals for display refresh. IC Role / Device Role / Timing Role: SPI-accessible scratchpad RAM interfacing directly with PIC MCU's hardware SPI port; provides deterministic <50 ns output valid delay after SCK low. Use Value: Eliminates need for parallel SRAM and address latches, reducing BOM count by 4 components while maintaining 20 MHz burst read capability for smooth gauge animation. |
Use Scenario: Buffering sensor readings (temperature, pressure, vibration) during network downtime in factory automation controllers. IC Role / Device Role / Timing Role: High-reliability serial memory holding up to 8 KB of time-stamped samples; accessed via sequential read mode with automatic 0x1FFF→0x0000 rollover. Use Value: Enables uninterrupted 32-sample/page writes at 10 kHz sample rate without CPU intervention, leveraging HOLD to defer transfers during EtherCAT sync windows. |
| Medical Infusion Pump UI | Smart Energy Meter |
|
Use Scenario: Caching patient dose history and alarm logs in battery-powered portable infusion devices. IC Role / Device Role / Timing Role: Low-quiescent-current SRAM retaining data during main power loss; retains contents down to 1.2 V (VDR spec) with no refresh required. Use Value: Supports >72-hour backup runtime on coin cell using only 4 µA standby draw, meeting IEC 60601-1 clause 15.4.2.2 for critical data retention. |
Use Scenario: Storing tariff schedules, demand-response event timestamps, and tamper logs in ANSI C12.20-compliant meters. IC Role / Device Role / Timing Role: SPI memory co-located with metrology SoC; withstands −40°C to +85°C ambient per ANSI C12.1 Table 4B thermal class. Use Value: Delivers guaranteed 100,000 write cycles and data retention >10 years at +85°C, satisfying ANSI C12.19 Annex D endurance requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Cypress CY14V101QS | 128 Kbit density, NVSRAM with integrated lithium battery backup; 55 ns access vs. 23K640's 25 ns tCLD | Used where persistent storage across power cycles is mandatory without external backup circuitry | Select when data retention during main power loss is required without discrete supercap/battery design |
| ON Semiconductor CAT24C512 | I²C interface (not SPI), 512 Kbit EEPROM; write cycle time ~5 ms vs. 23K640's sub-µs random write | Deployed in slow-control systems where byte-level nonvolatility outweighs speed, e.g., calibration storage | Choose only if existing I²C bus infrastructure exists and write endurance >1 M cycles is needed over speed |
Compared with CY14V101QS and CAT24C512, the 23K640-I/SN offers optimal balance of SPI-native speed, low active/standby current, and industrial temp support - making it preferred for real-time buffering where deterministic latency and minimal power dominate over nonvolatile persistence.
Availability
23K640-I/SN is available at Aetrix Electronics and suitable for automotive instrument clusters, industrial PLC data loggers, medical infusion pump UIs, and smart energy meters requiring stable component supply across extended product lifecycles.
Supply support for 23K640-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, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The 23K640 belongs to Microchip's serial SRAM product line, engineered specifically for SPI-based memory expansion in resource-constrained embedded systems where low power, small footprint, and industrial-grade reliability are critical.
FAQ
What is the maximum clock frequency supported by the 23K640-I/SN?
The 23K640-I/SN supports up to 20 MHz clock frequency at VCC = 3.0 V and TA = −40°C to +85°C (DS22126E, Table 1-2, Param No. 1). This enables peak data rates of 2.5 MB/s in sequential read mode. At lower VCC (e.g., 2.7 V), the maximum rated frequency reduces to 16 MHz per AC characterization limits.
Does the 23K640-I/SN require external pull-up resistors on its SPI lines?
No external pull-ups are required on SI, SO, or SCK for normal operation of the 23K640-I/SN. However, CS and HOLD must be actively driven: CS should be pulled high via MCU GPIO or external resistor when inactive, and HOLD must be held high (typically via MCU GPIO or 10 kΩ pull-up) when not in use to prevent unintended suspension of SPI transfers.
How does the HOLD function behave during an active write operation in the 23K640-I/SN?
When HOLD is asserted low during an active write sequence in the 23K640-I/SN, the device immediately places SO in high-impedance state and ignores further SI and SCK transitions. The internal address pointer and write state are preserved. Resuming requires bringing HOLD high while SCK is low - then continuing the clock sequence from the exact point of suspension without retransmission.
What is the meaning of "NC" on Pin 3 of the 23K640-I/SN SOIC package?
Pin 3 of the 23K640-I/SN is designated NC (No Connect) per DS22126E-page 13 Pin Function Table. It is an unconnected die pad with no internal bond wire. PCB layout guidelines recommend leaving it floating or connecting it to GND for mechanical stability - but it must never be driven or used as a signal path, as it has zero electrical function in the 23K640-I/SN.
Can the 23K640-I/SN operate reliably at 3.6 V supply voltage?
Yes, the 23K640-I/SN is fully specified for operation at 3.6 V - its VCC absolute maximum rating is 4.5 V, and DC characteristics (DS22126E, Table 1-1, D001) confirm 2.7–3.6 V operating range. At 3.6 V, ICC Read rises to 10 mA (at 20 MHz), and standby current remains ≤5 µA even at +125°C for E-temp variants - confirming robustness at upper rail.
23K640-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:
- 2.7V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
23K640-I/SN FAQ
1.How can I place an order for 23K640-I/SN through Aetrix?
Please submit a Request for Quotation (RFQ) for 23K640-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 23K640-I/SN reliable?
The price and inventory of 23K640-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 23K640-I/SN is usually 5 days.
3.What payment methods are accepted for 23K640-I/SN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 23K640-I/SN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 23K640-I/SN?
23K640-I/SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 23K640-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 23K640-I/SN?
For technical support, including 23K640-I/SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 23K640-I/SN requirements.
6.How does Aetrix verify that 23K640-I/SN is sourced from the original manufacturer or authorized distributors?
All 23K640-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 23K640-I/SN meets industry standards.
7.What is the process for return or replacement of 23K640-I/SN?
All 23K640-I/SN units undergo pre-shipment inspection (PSI). If there is an issue with 23K640-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 23K640-I/SN part is unused and in its original packaging.
Return procedure for 23K640-I/SN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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