Microchip Technology 23A1024T-E/ST

Overview

23A1024T-E/ST from Microchip Technology is a 1 Mbit (128K × 8) low-voltage SPI Serial SRAM with SDI and SQI interface support, operating from 1.7–2.2 V over –40°C to +125°C. It delivers 20 MHz clock rate in I-temp and 16 MHz in E-temp, features zero write time, unlimited read/write cycles, and 32-byte page architecture. It serves as fast-access nonvolatile-adjacent memory in automotive infotainment boot loaders and real-time data buffering for engine control units.

For engineers reviewing the 23A1024T-E/ST datasheet, 23A1024T-E/ST pinout, 23A1024T-E/ST application, or 23A1024T-E/ST equivalent, this page provides verified electrical specs, validated pin functions across SPI/SDI/SQI modes, confirmed automotive-grade temperature operation, and direct alternative part comparisons with documented functional trade-offs.

Technical Context

The 23A1024T-E/ST implements a serial SRAM core with three configurable access modes-Byte, Page, and Sequential-controlled via a writable 8-bit MODE register (bits 7:6 define mode). It supports three bus protocols: standard SPI (4-pin), SDI (dual I/O using SI/SO bidirectionally), and SQI (quad I/O using SIO0–SIO3), each requiring distinct command sequences (EDIO/EQIO/RSTIO) to enter or exit.

Its HOLD pin enables mid-sequence suspension in SPI/SDI modes only; HOLD is repurposed as SIO3 in SQI mode, disabling hold functionality. The device powers on in Standby mode (CS = high), requires CS low-to-high transition to initiate operations, and retains RAM data down to 1.0 V (VDR).

Key Specifications

Pinout & Package

8-lead TSSOP (4.4 mm body width), RoHS-compliant, moisture-sensitive level 3 (MSL3).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial SRAM applications.

Compared with 23LC1024T-E/ST, the 23A1024T-E/ST offers lower supply voltage compatibility critical for modern 1.8 V automotive MCUs, while FM25V10-G trades E-temp support for significantly reduced active current-making each optimal for distinct power/temperature/system-voltage constraints.

Availability

23A1024T-E/ST is available at Aetrix Electronics and suitable for automotive ECU development, industrial PLC data logging, and medical infusion pump controller design requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 23A1024T-E/ST 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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 23A1024/23LC1024 family was designed specifically for high-reliability serial memory applications in automotive, industrial, and medical systems requiring fast, endurance-free, low-voltage SRAM with multi-protocol flexibility.

FAQ

What is the maximum clock frequency supported by the 23A1024T-E/ST in automotive temperature conditions?

The 23A1024T-E/ST supports a maximum clock frequency of 16 MHz when operating across its full automotive temperature range of –40°C to +125°C (E-temp grade). This is specified in Table 1-2 AC Characteristics and applies to all bus modes-SPI, SDI, and SQI. At room temperature or industrial grade (I-temp), it supports up to 20 MHz, but that rating is not valid for E-temp operation. The 23A1024T-E/ST must be operated within the 16 MHz limit in automotive under-hood environments to ensure timing compliance and data integrity.

Does the 23A1024T-E/ST support Quad SPI (QSPI) mode, and how is it enabled?

Yes, the 23A1024T-E/ST supports Serial Quad Interface (SQI) mode, which transfers four bits per clock cycle using SIO0–SIO3 pins. It is enabled by issuing the EQIO command (0x38) via the SPI interface while the device is selected. Once entered, the HOLD pin becomes SIO3, and the HOLD function is disabled. To revert, the RSTIO command (0xFF) must be sent in SQI mode. The 23A1024T-E/ST datasheet confirms SQI support in the Device Selection Table and Section 4.2. SQI mode is fully supported at 16 MHz in E-temp.

What is the purpose of the HOLD pin on the 23A1024T-E/ST, and does it function in all bus modes?

The HOLD pin on the 23A1024T-E/ST suspends ongoing serial communication without resetting the internal address pointer-allowing the host to service higher-priority interrupts and resume transmission seamlessly. However, HOLD functionality is only active in SPI and SDI modes. In SQI mode, pin 7 is repurposed as SIO3, and HOLD is disabled. The 23A1024T-E/ST datasheet explicitly states this limitation in Section 3.6 and Figure 3-1. Therefore, HOLD cannot be used during SQI operation, and alternate flow control must be implemented in firmware.

How does the 23A1024T-E/ST handle power loss, and what is its minimum retention voltage?

The 23A1024T-E/ST guarantees data retention down to a minimum supply voltage of 1.0 V (VDR parameter, Table 1-1), meaning RAM contents remain intact even during brown-out events or backup-supply transitions as long as VCC stays ≥1.0 V. This specification is tested per JEDEC standards and is independent of temperature grade. Unlike flash, the 23A1024T-E/ST requires no write-cycle delay or erase step-so data written just before voltage collapse remains valid. This behavior is intrinsic to SRAM architecture and is confirmed for the 23A1024T-E/ST in DS20005142C, Note 2.

Is the 23A1024T-E/ST pin-compatible with the 23LC1024T-E/ST, and can they be substituted without PCB changes?

Yes, the 23A1024T-E/ST and 23LC1024T-E/ST are fully pin-compatible and share identical 8-lead TSSOP (ST) packaging, pinout, instruction set, and timing specifications. The only differences are supply voltage range (1.7–2.2 V vs. 2.5–5.5 V) and associated DC parameters (e.g., ICC, VIH/VIL thresholds). Because pin assignments, package dimensions, and footprint are identical, substitution requires no PCB changes-but system-level validation of voltage margins, level-shifting, and timing under the new VCC range is mandatory. This compatibility is documented in the Device Selection Table of DS20005142C.