Asahi Kasei Microdevices/AKM AK93C45AF

Overview

AK93C45AF from Asahi Kasei is a 1K-bit (1024-bit), 64 × 16 organization serial CMOS EEPROM with SPI-compatible 4-wire interface (CS, SK, DI, DO), operating from 1.8V to 5.5V supply, rated for -40°C to +85°C, and housed in an 8-pin SOP package. It supports READ, WRITE, EWEN, and EWDS instructions, features software-controlled write protection, and delivers 100K write/erase cycles with 10-year data retention - used for configuration storage in industrial controllers and sensor calibration modules.

For engineers reviewing the AK93C45AF datasheet, AK93C45AF pinout, AK93C45AF application, or AK93C45AF equivalent, key selection considerations include its 1.8V–5.5V wide V_CC range, 0.8µA max standby current, Busy/Ready status via DO pin, NC/PE pin configuration in SOP, and compatibility with microcontroller GPIO-based serial interfaces requiring no external high-voltage programming supply.

Technical Context

The AK93C45AF implements a synchronous serial interface with chip-select (CS) activation, rising-edge clocked data transfer on SK, and bidirectional data flow via DI (input) and DO (output). Its internal architecture includes instruction decode logic, auto-erase control, and a charge-pump-based high-voltage generator enabling write operations without external V_PP.

Write enable requires explicit EWEN instruction before WRITE; execution reverts to disabled state after EWDS or power removal. The DO pin serves dual function: data output during READ and open-drain Busy/Ready status (low = busy, high = ready) when CS is active and post-write - with timing validity dependent on t_CS ≥ 250ns and t_SV ≤ 500ns (CL = 100pF).

Key Specifications

Pinout & Package

AK93C45AF uses an 8-pin plastic SOP (Small Outline Package) with NC (No Connect) on Pin 3; PE (Program Enable) is not bonded and internally pulled up, so it is functionally inactive in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA010A-I/P and CAT25010VI-GT3, AK93C45AF uniquely integrates a charge pump and Busy/Ready signaling within its 1.8V–5.5V envelope - reducing system-level timing uncertainty and eliminating external high-voltage generation, making it optimal for compact, low-power, and dynamically configurable embedded designs.

Availability

AK93C45AF is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded controller configuration, and medical device settings backup requiring stable component supply, long-lifecycle support, and guaranteed traceability.

Supply support for AK93C45AF 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

Asahi Kasei is a Japanese semiconductor manufacturer specializing in analog, mixed-signal, and memory ICs for industrial, automotive, and consumer applications.

The AK93C45A family was designed specifically for low-density, low-power, wide-V_CC serial data storage in space-constrained embedded systems - emphasizing reliability, ease of integration, and elimination of external programming voltage sources.

FAQ

What is the memory organization of the AK93C45AF?

The AK93C45AF contains 1024 bits organized as 64 words × 16 bits per word. This structure supports efficient storage of 16-bit configuration registers, calibration coefficients, or status flags. Each READ or WRITE instruction accesses one 16-bit location using a 6-bit address (A5–A0), and the DO pin outputs or accepts exactly 16 data bits per transaction. The AK93C45AF does not support byte-level addressing - all operations are strictly 16-bit aligned.

Does the AK93C45AF require an external V_PP supply for write operations?

No, the AK93C45AF does not require an external V_PP supply. It integrates an on-chip charge pump that generates the necessary high voltage for write/erase operations from the standard V_CC rail (1.8V–5.5V). This eliminates the need for external high-voltage circuitry, simplifies PCB layout, and reduces bill-of-materials cost - a key differentiator versus older EEPROM families like the 93C46 or Microchip 25-series without internal pumps.

How does write protection work on the AK93C45AF?

Write protection on the AK93C45AF is software-controlled via EWEN (Erase/Write Enable) and EWDS (Erase/Write Disable) instructions. At power-up, the device defaults to EWDS state - WRITE instructions are ignored until EWEN is issued. After successful EWEN, WRITE and EWDS become executable; issuing EWDS immediately disables further writes. This mechanism provides flexible, firmware-driven protection without hardware pins or jumpers - critical for field-upgradable systems where dynamic lock/unlock behavior is required.

What is the function of the DO pin during and after a WRITE instruction?

During a WRITE instruction, the DO pin remains in high-impedance state. After the falling edge of CS initiates the self-timed programming cycle, and if CS is brought high again after ≥250ns, the DO pin transitions to active output mode: logic "0" indicates programming is still in progress (Busy), and logic "1" confirms completion (Ready). This status remains valid until the next instruction's start bit is detected. The AK93C45AF uses this feature to eliminate fixed-delay polling - firmware can wait on DO=1 before issuing subsequent commands.

Is the AK93C45AF pin-compatible with other variants in the AK93CxxA family?

The AK93C45AF shares the same 8-pin SOP footprint and pinout with AK93C55AF, AK93C65AF, and AK93C75AF - all use CS/SK/DI/DO/GND/VCC/NC/NC arrangement. However, memory size, address width (A5 vs A6/A7/A8), and instruction encoding differ. While PCB layout is interchangeable, firmware must be adapted for each variant's address depth and timing (e.g., t_E/W = 10ms for AK93C45AF vs 8–10ms for AK93C75AF). No functional drop-in replacement exists without software revision.