Based on the model number **AS4CT-S15-R/Q**, this part belongs to the **AS4CT series** of high-speed CMOS Static Random Access Memory (SRAM) manufactured by **Alliance Memory**. Below is a detailed breakdown of its electronic specifications and characteristics. --- ### 1. General Specifications The AS4CT-S15-R/Q is a **4-Megabit (4Mb)** asynchronous SRAM. These parts are designed for low-power applications and high-speed data processing. | Feature | Specification | | :--- | :--- | | **Density** | 4 Megabit (256K x 16 or 512K x 8 configuration) | | **Technology** | CMOS (Low Power) | | **Interface** | Asynchronous (No clock required) | | **Access Time** | 10ns to 15ns (indicated by "15" in the part number) | | **Voltage Supply** | Typically 3.3V (VCC range 2.7V - 3.6V) | --- ### 2. Part Number Decoder Understanding the suffixes helps identify the specific environmental and performance ratings: * **AS4CT**: Alliance Memory Synchronous/Asynchronous CMOS series. * **S**: Designates the specific package or die revision. * **15**: Speed Grade. Indicates an access time of **15 nanoseconds**. * **R**: Generally refers to the **Tape and Reel** packaging format. * **Q**: Refers to the **Automotive Grade** (AEC-Q100 compliant) or an extended temperature range. --- ### 3. Pin Functionality (Common for 4Mb SRAM) Most 4Mb SRAM chips in this family utilize a standard pinout to ensure compatibility with memory controllers: | Pin Name | Type | Description | | :--- | :--- | :--- | | **A0 - A17** | Input | Address Inputs (selects the memory location). | | **DQ0 - DQ15** | I/O | Data Inputs/Outputs (bi-directional bus). | | **CE#** | Input | Chip Enable (activates the device). | | **WE#** | Input | Write Enable (controls write operations). | | **OE#** | Input | Output Enable (controls data output buffers). | | **LB# / UB#** | Input | Lower Byte / Upper Byte control (for 16-bit mode). | --- ### 4. Key Features & Applications * **Low Power Consumption:** Features a "Standby" mode that significantly reduces current draw when the chip is not being accessed. * **TTL Compatible:** The inputs and outputs are compatible with standard logic levels. * **Reliability:** The "Q" rating indicates it is suitable for harsh environments, such as automotive infotainment, industrial automation, and telecommunications infrastructure. ---