Microchip Technology 23A1024-I/ST

Overview

23A1024-I/ST from Microchip Technology is a 1 Mbit (128K × 8) SPI Serial SRAM with dual- and quad-interface support, operating from 1.7–2.2 V at industrial temperature (−40°C to +85°C). It delivers 20 MHz clock rate in SPI/SDI/SQI modes, 3 mA read current at 2.2 V, and zero write time-enabling fast, low-voltage data buffering in microcontroller-based edge sensor nodes.

For engineers reviewing the 23A1024-I/ST datasheet, 23A1024-I/ST pinout, 23A1024-I/ST application, or 23A1024-I/ST equivalent, this page provides verified package mapping (8-lead TSSOP), confirmed SDI/SQI command set (EDIO/EQIO/RSTIO), validated timing parameters (e.g., TCSS = 25 ns, TV = 25 ns), and real-world use cases in battery-powered telemetry and firmware overlay storage.

Technical Context

The 23A1024-I/ST implements a serial memory controller with three configurable access modes-Byte, Page (32-byte), and Sequential-selected via a writable MODE register. Its SPI-compatible bus supports full-duplex operation with CS, SCK, SI, and SO pins, while SDI mode enables bidirectional 2-bit-per-clock transfers on SI/SO, and SQI mode adds SIO2/SIO3 for 4-bit-per-clock throughput.

It features hardware HOLD functionality in SPI/SDI modes (suspended transfers without sequence restart), but HOLD is disabled in SQI mode where SIO2 and SIO3 become active I/O lines. The device powers up in Standby mode (CS high), requires no external refresh, and retains data down to 1.0 V VCC.

Key Specifications

Pinout & Package

8-lead TSSOP (ST package), 4.4 mm body width, RoHS-compliant matte tin finish. Pin 1 marked by notch or dot; pin 3 (SIO2) unused in SPI/SDI modes and must be pulled high or tied to VCC to prevent floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 23LC1024-I/ST, the 23A1024-I/ST offers tighter 1.7–2.2 V operation critical for energy harvesting, while IS61WV102416BLL-10MLI trades serial simplicity for raw speed and width-making it unsuitable for space-constrained, low-power edge nodes.

Availability

23A1024-I/ST is available at Aetrix Electronics and suitable for smart metering, firmware update staging, battery-powered telemetry, and industrial sensor fusion requiring stable component supply across extended product lifecycles.

Supply support for 23A1024-I/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, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 23A1024-I/ST belongs to Microchip's serial SRAM product line, engineered specifically for low-voltage, low-power embedded systems needing reliable, high-speed nonvolatile data buffering without refresh overhead.

FAQ

What is the maximum clock frequency supported by the 23A1024-I/ST in industrial temperature range?

The 23A1024-I/ST supports up to 20 MHz clock frequency across its full industrial temperature range (−40°C to +85°C), as specified in Table 1-2 AC Characteristics. This applies to all interface modes-SPI, SDI, and SQI-and is validated under worst-case VCC (1.7 V) and temperature conditions. The 23A1024-I/ST maintains timing compliance without derating at 20 MHz, unlike E-temp variants which are limited to 16 MHz.

Does the 23A1024-I/ST support true hardware write protection or sector locking?

No, the 23A1024-I/ST does not include hardware write protection, sector lock bits, or software-controlled write disable features. All memory locations are freely writable at any time when CS is asserted and valid WRITE or WRMR commands are issued. Protection must be implemented externally via GPIO-controlled CS gating or MCU firmware logic. The 23A1024-I/ST relies on unlimited endurance and zero write time rather than security-oriented locking mechanisms.

Can the 23A1024-I/ST operate in SQI mode while retaining HOLD functionality?

No-the HOLD pin (Pin 7) functions exclusively as SIO3 (Serial I/O 3) in SQI mode and cannot be used for hold suspension. Section 3.6 explicitly states "Hold functionality is not available when operating in SQI bus mode." To use HOLD, the device must remain in SPI or SDI mode. If SQI throughput is required, suspend/resume must be handled at the MCU firmware level using CS control instead of the hardware HOLD signal.

What is the purpose of the "don't care" bits in the 24-bit address field for READ and WRITE instructions?

The first seven MSBs of the 24-bit address are designated "don't care" in READ and WRITE instructions because the 23A1024-I/ST's 128K × 8 memory array requires only 17 address bits (2¹⁷ = 131,072 bytes). Bits A23–A17 are ignored during addressing, allowing simplified address generation in firmware and compatibility with 24-bit-aligned memory maps. This behavior is consistent across all modes and is documented in Sections 2.3 and 2.4 of the datasheet for the 23A1024-I/ST.

How does the 23A1024-I/ST handle power loss during a write cycle?

The 23A1024-I/ST guarantees data integrity during power loss only if VCC remains ≥1.0 V (the Data Retention Voltage, D011) throughout the write sequence. Below 1.0 V, RAM contents may be corrupted. Because it is volatile SRAM-not nonvolatile FRAM or EEPROM-it has no built-in power-loss write protection or auto-save. System-level safeguards (e.g., brown-out detection, capacitor hold-up, or external NVSRAM) must be implemented to ensure write completion before VCC collapse. This applies identically to all 23A1024-I/ST operations.