HM5225645F

HM5225645F 256-Mbit SDRAM Technical Summary

Overview

The Hitachi HM5225645F is a high-performance 256-Mbit Synchronous Dynamic Random-Access Memory (SDRAM) designed for applications requiring high-speed data transfer and efficient memory management. Organized as 1,048,576 words × 64-bit × 4 banks, this SDRAM provides a wide data bus solution ideal for memory-intensive systems. Its counterpart, the HM5225325F, offers a 32-bit configuration (2,097,152 words × 32-bit × 4 banks), catering to different system requirements. Both variants operate with a 3.3V power supply and feature a low-voltage TTL (LVTTL) interface, ensuring compatibility with modern digital systems.

Key Features

• High-Density Memory: 256-Mbit capacity with flexible organization (×64 or ×32 configurations).
• Multi-Bank Architecture: Four independent banks enable concurrent operations, improving system throughput.
• High-Speed Operation: Maximum clock frequency of 100 MHz for fast data access.
• LVTTL Interface: Ensures compatibility with standard logic levels.
• Compact Packaging: 108-ball BGA (Ball Grid Array) with a 1.27 mm pitch, minimizing PCB footprint.
• Burst Mode Support: Programmable burst lengths (4, 8, or full page) with sequential or interleaved sequencing options.
• CAS Latency Flexibility: Programmable CAS latency of 2 or 3 cycles for performance optimization.
• Byte-Level Control: Data mask (DQMB) functionality for selective write operations.
• Refresh Options: Supports both auto-refresh and self-refresh modes, with 4096 refresh cycles required every 64 ms.
• Burst Stop Capability: Allows premature termination of burst operations for dynamic control.

Applications

The HM5225645F is suited for a wide range of applications requiring high-speed, high-density memory, including:

• Computing Systems: Servers, workstations, and high-performance computing platforms.
• Networking Equipment: Routers, switches, and network interface cards.
• Embedded Systems: Industrial controllers, automation systems, and real-time processing units.
• Graphics Processing: Video cards and display controllers requiring fast memory access.
• Telecommunications: Base stations and communication infrastructure.

Electrical Characteristics

The following table summarizes the key electrical specifications of the HM5225645F:

• Supply Voltage (V_DD): 3.3V ± 0.3V
• Operating Current: Dependent on clock frequency and operational mode (refer to datasheet for detailed values).
• Standby Current: Reduced in self-refresh mode for power-sensitive applications.
• Input/Output Logic Levels: LVTTL-compatible (V_IH = 2.0V min, V_IL = 0.8V max).
• Clock Frequency: Up to 100 MHz (10 ns cycle time).
• Data Access Time: Defined by CAS latency (CL=2 or CL=3).

Package Information

The HM5225645F is available in a compact 108-ball BGA package with the following specifications:

• Package Type: BP-108 (Ball Grid Array)
• Ball Pitch: 1.27 mm
• Dimensions: Refer to manufacturer datasheet for exact mechanical drawings.
• Thermal Characteristics: Designed for efficient heat dissipation in high-density PCB layouts.

Ordering Information

The HM5225645F is available in multiple variants, including:

• HM5225645F-B60: 64-bit wide configuration with specific timing grade.
• HM5225325F-B60: 32-bit wide configuration with identical performance characteristics.

For detailed ordering codes and additional options, consult the manufacturer's product documentation.

Conclusion

The Hitachi HM5225645F 256-Mbit SDRAM is a versatile and high-performance memory solution suitable for demanding applications. Its multi-bank architecture, programmable burst modes, and compact BGA packaging make it an excellent choice for systems requiring efficient memory utilization and high-speed data access. Engineers and designers can leverage its features to optimize performance in computing, networking, and embedded applications.