HM5264405 Series 64-Mbit SDRAM Technical Summary

Overview

The HM5264405 series from Hitachi represents a family of high-performance 64-Mbit Synchronous DRAM (SDRAM) components designed for memory-intensive applications. These devices are available in three configurations with different word organizations:

• HM5264165F: 1,048,576-word × 16-bit × 4 bank organization
• HM5264805F: 2,097,152-word × 8-bit × 4 bank organization
• HM5264405F: 4,194,304-word × 4-bit × 4 bank organization

All variants feature fully synchronous operation referenced to the rising edge of the clock input and are packaged in a space-efficient 54-pin plastic TSOP II package. The devices are optimized for high-speed operation with a 3.3V power supply and LVTTL interface compatibility.

Key Features

Architecture and Performance

• 64-Mbit density with 4-bank architecture
• 3.3V ±0.3V power supply (LVTTL interface)
• High clock frequency support:
  • 133MHz (7.5ns cycle time) for -75 speed grade
  • 100MHz (10ns cycle time) for -A60/B60 speed grades
• All inputs and outputs synchronized to rising clock edge

Memory Control Features

• Programmable burst length: 1, 2, 4, 8 or full page
• Two burst sequence modes:
  • Sequential (supports all burst lengths)
  • Interleave (supports BL=1,2,4,8)
• Programmable CAS latency: 2 or 3 cycles
• Byte control via DQM (DQMU/DQML for x16 version)

Refresh Options

• 4096 refresh cycles every 64ms
• Two refresh modes:
  • Auto refresh
  • Self refresh

Applications

The HM5264405 series is suitable for a wide range of applications requiring high-density, high-speed memory:

• Computer systems and workstations
• Networking equipment (routers, switches)
• Telecommunications infrastructure
• High-performance embedded systems
• Graphics and video processing
• Industrial control systems
• Test and measurement equipment

Electrical Characteristics

Absolute Maximum Ratings

• Supply voltage (VDD, VDDQ): -0.5V to +4.6V
• Input voltage (VI): -0.5V to VDDQ+0.5V
• Output voltage (VO): -0.5V to VDDQ+0.5V
• Operating temperature range: 0°C to +70°C
• Storage temperature range: -55°C to +125°C

Recommended Operating Conditions

• Supply voltage (VDD, VDDQ): 3.3V ±0.3V
• Input high voltage (VIH): 2.0V min
• Input low voltage (VIL): 0.8V max
• Operating temperature: 0°C to +70°C

DC Characteristics

• Input leakage current (II): ±1μA max
• Output leakage current (IOZ): ±1μA max
• Operating current (IDD):
  • Active: 120mA typ (100MHz operation)
  • Standby: 20mA max
• Self refresh current (IDD6): 400μA max

Package Information

54-pin TSOP II Package Details

• Package dimensions: 22.2mm × 10.2mm × 1.2mm (typ)
• Lead pitch: 0.8mm
• Lead count: 54 pins
• Package material: Plastic
• Moisture sensitivity level (MSL): 3

Pin Configuration

The 54-pin TSOP II package includes the following key signal groups:

• Clock and control signals (CLK, CKE, /CS, /RAS, /CAS, /WE)
• Address inputs (A0-A11)
• Bank select (BA0, BA1)
• Data I/O (DQ0-DQ15 or DQ0-DQ7/DQ0-DQ3 depending on configuration)
• Data mask (DQM or DQMU/DQML)
• Power and ground (VDD, VDDQ, VSS, VSSQ)

Ordering Information

The devices are available in different speed grades and configurations:

• HM5264165F-75: x16 organization, 133MHz operation
• HM5264165F-A60: x16 organization, 100MHz operation
• HM5264805F-B60: x8 organization, 100MHz operation
• HM5264405F-75: x4 organization, 133MHz operation

Functional Description

Bank Architecture

The 4-bank architecture allows simultaneous activation of different rows in different banks, enabling efficient memory access patterns. Each bank operates independently with its own row decoder and sense amplifiers.

Burst Operation

The device supports both burst read/write and burst read/single write operations. The programmable burst length (1, 2, 4, 8 or full page) and selectable burst sequence (sequential or interleave) provide flexibility for different access patterns.

Refresh Modes

The auto refresh mode requires external refresh control, while the self refresh mode maintains data integrity with minimal power consumption during periods of inactivity. The distributed refresh scheme ensures uniform refresh timing across all memory cells.

Conclusion

The HM5264405 series of 64-Mbit SDRAMs from Hitachi provides a high-performance memory solution for demanding applications. With its flexible organization options, advanced bank architecture, and robust feature set, these devices offer system designers an optimal balance of performance, power efficiency, and density. The standardized TSOP II package ensures compatibility with existing designs and manufacturing processes.