23K256-I/ST

Memory IC Overview

The Microchip Technology 23K256-I/ST is a 256 Kbit (32,768 x 8-bit) Serial SRAM device designed for low-power applications. It operates within a supply voltage range of 2.7V to 3.6V and supports a maximum clock frequency of 20 MHz. The device features a standard SPI-compatible serial interface requiring SCK, SI, SO, and CS signals, along with a dedicated HOLD pin for pausing communication. It offers three operating modes: Byte, Page (32-byte page size), and Sequential. The Industrial temperature grade (-40°C to +85°C) ensures reliability in demanding environments. Key electrical characteristics include a read current of 3 mA at 1 MHz and a maximum standby current of 4 µA at +85°C.

Memory IC Feature Summary

• Supports flexible memory access through Byte, Page, and Sequential operation modes selectable via the STATUS register.
• Includes a HOLD input pin that suspends serial communication without resetting the internal address pointer, allowing host interruption handling.
• Utilizes low-power CMOS technology to minimize energy consumption during both active read operations and standby states.
• Interfaces directly with microcontrollers via a simple four-wire Serial Peripheral Interface (SPI) compatible bus.

Memory IC Applications

• Data logging systems requiring non-volatile-like temporary storage with fast access times
• Microcontroller-based embedded systems needing extended RAM via SPI expansion
• Industrial control units operating within specified industrial temperature ranges
• Portable battery-powered devices utilizing low standby current capabilities

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 voltage variant distinct from the 'A' series. Ensure compliance requirements such as Pb-free and RoHS status are documented in the final purchase order specifications.

Memory IC Selection Notes

Select this component when an SPI interface is required for SRAM expansion in space-constrained designs using the TSSOP package. Choose the 23K256 over the 23A256 if the system operates above 1.95V, as the latter is limited to 1.5V-1.95V. Consider the HOLD pin functionality if the application requires interrupting ongoing serial transfers without data loss or re-initialization.

Memory IC Part Context

The 23K256 belongs to the 23X256 family of 256 Kbit Serial SRAMs manufactured by Microchip Technology. This family includes variants like the 23A256, which differs primarily in its lower voltage operating range. The devices share identical pinouts, instruction sets, and functional behaviors, differing only in electrical specifications related to supply voltage and temperature grades.

Memory IC Replacement Considerations

The 23A256-I/ST is a functional substitute but is restricted to a 1.5V-1.95V supply range; it is not compatible with 2.7V-3.6V systems. Other 23X256 variants with different package codes (e.g., SN for SOIC) may be used if board layout allows for package conversion.