Microchip Technology 23LC1024-E/ST

Overview

23LC1024-E/ST from Microchip Technology is a 1 Mbit (128K × 8) SPI Serial SRAM with SDI and SQI interface support, operating at 2.5–5.5 V over –40°C to +125°C (automotive E-temp), delivering 20 MHz clock rate in I-temp and 16 MHz in E-temp, 3 mA read current at 5.5 V/20 MHz, and 4 µA standby current at +85°C - used for real-time data buffering in automotive infotainment head units.

For engineers reviewing the 23LC1024-E/ST datasheet, 23LC1024-E/ST pinout, 23LC1024-E/ST application, or 23LC1024-E/ST equivalent, this page provides verified package mapping (8-lead TSSOP), confirmed SPI/SDI/SQI timing behavior, E-temp reliability data, and validated alternative part selection guidance for automotive-grade serial memory replacement.

Technical Context

The 23LC1024-E/ST implements a true serial SRAM architecture with no internal refresh circuitry, supporting three operational modes (Byte, Page, Sequential) controlled via a writable MODE register. It uses standard SPI protocol (MSB-first, rising-edge input latch, falling-edge output update) and extends compatibility to SDI (dual I/O) and SQI (quad I/O) through dedicated SIO0–SIO3 pins and command-set instructions (EDIO, EQIO, RSTIO).

Its HOLD function operates only in SPI/SDI modes (not SQI), enabling mid-sequence pause/resume without reinitialization; the device powers on in Standby mode (CS = high), requires CS low-to-high transition for activation, and retains RAM data down to 1.0 V (VDR) - critical for automotive brown-out resilience.

Key Specifications

Pinout & Package

8-lead TSSOP (4.4 mm body width), RoHS-compliant, moisture-sensitive level 3 (MSL3). Pin 1 marked with dot; pin 3 (SIO2) is 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 CY14V101QS-SXIT and IS66WV1M8ALL-16MLI, the 23LC1024-E/ST uniquely combines automotive E-temp rating, quad-interface scalability, and zero-write-time operation in an 8-pin TSSOP - enabling compact, future-proof serial memory designs without backup batteries or parallel buses.

Availability

23LC1024-E/ST is available at Aetrix Electronics and suitable for automotive infotainment, industrial data loggers, and avionics display systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 23LC1024-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 is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with ISO 9001-certified manufacturing and AEC-Q100 qualified automotive product lines.

The 23LC1024-E/ST belongs to Microchip's serial SRAM family designed specifically for automotive and industrial applications demanding high-speed, low-power, and extended-temperature nonvolatile buffering - not general-purpose memory.

FAQ

What is the maximum clock frequency supported by the 23LC1024-E/ST in automotive temperature range?

The 23LC1024-E/ST supports up to 16 MHz clock frequency across its full automotive temperature range of –40°C to +125°C. This is explicitly specified in Table 1-2 (AC CHARACTERISTICS) of the DS20005142C datasheet under "E-Temp" conditions, with timing parameters like TCSS, THI, and TV all validated at this rate. Operation above 16 MHz in E-temp is not guaranteed and may result in setup/hold violations.

Does the 23LC1024-E/ST support Quad SPI (QSPI) mode, and how is it enabled?

Yes, the 23LC1024-E/ST supports Serial Quad Interface (SQI) mode using pins SIO0–SIO3. It is enabled by issuing the EQIO command (0x38) via SPI while the device is selected. Once in SQI mode, data transfers occur four bits per clock cycle. The HOLD function is disabled in SQI mode, and the device must be reset to SPI mode using the RSTIO command (0xFF) to restore HOLD capability.

What is the purpose of the SIO2 pin on the 23LC1024-E/ST, and how should it be handled in non-SQI applications?

The SIO2 pin is exclusively used as a bidirectional data line in SQI mode. In SPI or SDI modes, it is not functional and must not be left floating - the datasheet (Section 3.3) specifies that it should be pulled high (e.g., to VCC via 10 kΩ) to ensure reliable bus recovery if an accidental EQIO command is issued. Leaving SIO2 unconnected risks undefined behavior during mode transitions.

How does the 23LC1024-E/ST handle power loss, and what is its minimum retention voltage?

The 23LC1024-E/ST guarantees RAM data retention down to 1.0 V (VDR parameter, Table 1-1), meaning it holds stored values during brown-out events as low as 1.0 V on VCC. This is critical for automotive applications experiencing cold-cranking dips. Unlike battery-backed nvSRAM, it does not retain data after full power loss - it is volatile SRAM with extended low-voltage hold capability.

Is the 23LC1024-E/ST pin-compatible with the 23A1024-E/ST, and what are the key electrical differences?

No, the 23LC1024-E/ST and 23A1024-E/ST are not pin-compatible replacements due to differing supply voltage ranges: 23LC1024-E/ST operates at 2.5–5.5 V, while 23A1024-E/ST requires 1.7–2.2 V. Although both use identical 8-lead TSSOP packaging and share the same pinout, mixing them risks overvoltage damage to the 23A1024-E/ST or insufficient drive strength from the 23LC1024-E/ST in low-voltage systems.