23K640-I/ST

Memory IC Overview

The Microchip Technology 23K640-I/ST is a 64-Kbit (8192 x 8-bit) low-power CMOS Serial SRAM device. It interfaces via a standard SPI-compatible serial bus with a maximum clock frequency of 20 MHz. The supply voltage range is 2.7 V to 3.6 V. It supports industrial temperature operation from -40°C to +85°C and features a 32-byte page size. The device is housed in an 8-lead TSSOP package.

Memory IC Feature Summary

• Supports flexible operating modes including byte read/write, 32-byte page mode, and sequential mode for efficient data transfer.
• Includes a dedicated HOLD pin that allows the host to pause serial communication without resetting the sequence or losing state.
• Features low-power CMOS technology with minimal standby current consumption when deselected.

Memory IC Applications

• Data logging systems requiring non-volatile-like temporary storage
• Microcontroller-based embedded applications needing fast random access memory
• Industrial control systems operating within extended temperature ranges

Memory IC Procurement Notes

Verify the specific suffix 'I' confirms the Industrial temperature range (-40°C to +85°C) and 'ST' denotes the 8-lead TSSOP package. Confirm the 'K' indicates the 2.7V–3.6V supply voltage variant distinct from the 1.7V–1.95V 'A' series. Ensure compatibility with the target SPI controller's voltage levels and timing requirements before integration.

Memory IC Selection Notes

Select this component when a small, high-speed serial RAM buffer is needed for microcontroller projects. It is suitable for designs requiring page-mode efficiency or sequential access across the entire array. Consider the TSSOP package for surface-mount assembly constraints and verify that the 20 MHz clock speed meets the system's throughput demands.

Memory IC Part Context

This part belongs to the 23X640 family of 64-Kbit Serial SRAMs manufactured by Microchip Technology. The family includes variants with different voltage ranges (23A640 for 1.7V–1.95V and 23K640 for 2.7V–3.6V) and temperature grades (Industrial and Automotive). The 23K640-I/ST specifically targets industrial applications requiring robust performance over a wide temperature span.

Memory IC Replacement Considerations

Direct substitutes within the same family include the 23K640-E/ST for automotive temperature ratings or the 23K640-I/SN for SOIC packaging. Cross-family replacements like the 23K256 offer larger capacity but share similar interface characteristics.

Memory IC FAQ

How does the HOLD pin function during serial communication?

The HOLD pin suspends transmission to the device while in the middle of a serial sequence. When pulled low, it places inputs in a high-impedance state, ignoring transitions on SI, SCK, and SO, allowing the host to service higher priority interrupts without retransmitting the sequence.

What are the available operating modes for the 23K640?

The device supports three modes selected via the STATUS register: Byte mode (single byte access), Page mode (access limited to a 32-byte page with automatic address increment), and Sequential mode (continuous access across page boundaries with address rollover).