HM5425401B DDR SDRAM Technical Summary

Overview

The HM5425401B is part of a series of Double Data Rate (DDR) Synchronous Dynamic Random-Access Memory (SDRAM) devices, which includes the HM5425161B and HM5425801B. These devices are designed for high-speed data transfer applications, leveraging a 2-bit prefetch pipelined architecture to achieve efficient performance. The HM5425401B operates with a 2.5V power supply and utilizes SSTL-2 interfaces for all inputs and outputs, ensuring compatibility with JEDEC standards.

Key to its operation is the use of data strobe (DQS) signals for both read and write operations, enabling reliable high-speed data bus design. The device also features an on-chip Delay Locked Loop (DLL), which can be enabled or disabled via an extended mode resistor setting. With four independently operable banks, the HM5425401B supports simultaneous operations, making it suitable for demanding memory applications.

Features

• JEDEC Standard Compatibility: Fully compliant with industry standards.
• Power Supply: 2.5V operation.
• Interface: SSTL-2 for all inputs and outputs.
• Clock Frequency: Supports 143 MHz, 133 MHz, 125 MHz, and 100 MHz.
• Data Synchronization: Data inputs, outputs, and DM are synchronized with DQS.
• Multi-Bank Operation: Four banks can operate simultaneously and independently.
• Burst Operations: Supports burst read/write with programmable burst lengths (2/4/8).
• Burst Sequence: Programmable for sequential or interleave modes.
• CAS Latency: Programmable to 2 or 2.5 cycles.
• Refresh Cycles: 8192 refresh cycles with 7.8 µs refresh interval.
• Refresh Modes: Supports auto-refresh and self-refresh.

Applications

The HM5425401B is designed for use in a variety of high-performance computing and embedded systems, including:

• Desktop and laptop computers
• Networking equipment such as routers and switches
• Graphics cards and video processing units
• Embedded systems requiring high-speed memory
• Industrial automation and control systems
• Telecommunications infrastructure

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (VCC): -0.5V to +3.6V
• Input Voltage (VIN): -0.5V to VCC + 0.5V
• Operating Temperature Range: 0°C to +70°C
• Storage Temperature Range: -55°C to +125°C

Recommended Operating Conditions

• Supply Voltage (VCC): 2.3V to 2.7V
• Input High Voltage (VIH): VREF + 0.18V to VCC + 0.3V
• Input Low Voltage (VIL): -0.3V to VREF - 0.18V
• Clock Frequency: Up to 143 MHz

Timing Parameters

• CAS Latency: 2 or 2.5 clock cycles
• tRCD (RAS to CAS Delay): 20 ns (min)
• tRP (RAS Precharge Time): 20 ns (min)
• tRAS (Active to Precharge Delay): 45 ns (min)
• tRC (Row Cycle Time): 65 ns (min)

Package Information

Ordering Information

• HM5425401BTT-75A: 143 MHz/133 MHz, 400-mil 66-pin TSOP II
• HM5425401BTT-75B: 133 MHz/100 MHz, 400-mil 66-pin TSOP II
• HM5425401BTT-10: 125 MHz/100 MHz, 400-mil 66-pin TSOP II

Pin Configuration

The HM5425401B is available in a 66-pin TSOP II package (TTP-66D). Below is a summary of key pins:

• A0-A14: Address inputs for row, column, and bank selection.
• DQ0-DQ3: Data input/output pins.
• DQS: Data strobe for input/output synchronization.
• CS: Chip select.
• RAS/CAS/WE: Command inputs for row/column addressing and write enable.
• DM: Input mask for write operations.
• CLK/CLK#: Differential clock inputs.
• CKE: Clock enable.
• VCC/VSS: Power and ground for internal circuits.
• VCCQ/VSSQ: Power and ground for DQ circuits.

Mechanical Dimensions

• Package Type: 66-pin TSOP II (TTP-66D)
• Width: 400 mil (10.16 mm)
• Height: 1.2 mm (max)
• Lead Pitch: 0.5 mm

Conclusion

The HM5425401B DDR SDRAM is a high-performance memory solution designed for applications requiring fast and reliable data transfer. With its JEDEC-compliant design, multi-bank architecture, and flexible timing options, it is well-suited for a wide range of computing and embedded systems. The 66-pin TSOP II package ensures compact integration while maintaining robust electrical performance.