Technical Summary: K4E640812D 8Mx8 EDO Mode DRAM

Overview

The K4E640812D is an 8Mx8 Extended Data Out (EDO) Mode DRAM component manufactured using Samsung's advanced CMOS process technology. This high-performance memory device offers 67,108,864 bits (8MB) of storage organized as 8,388,608 words by 8 bits. Designed for applications requiring high bandwidth and low power consumption, this DRAM features multiple refresh modes and operates with a 3.3V power supply, making it suitable for modern low-voltage systems.

The device incorporates several advanced features including EDO mode operation, multiple refresh capabilities, and fast parallel test mode. It is available in both standard and low-power (L-version) variants, with the L-version offering additional self-refresh capability for power-sensitive applications.

Key Features

• 8Mx8 organization (8,388,608 words × 8 bits)
• Extended Data Out (EDO) Mode operation for improved performance
• Multiple refresh capabilities:
  • CAS-before-RAS refresh
  • RAS-only refresh
  • Hidden refresh
  • Self-refresh capability (L-version only)
• Fast parallel test mode capability for efficient production testing
• LVTTL (3.3V) compatible inputs and outputs
• Flexible write modes:
  • Early Write mode
  • Output enable controlled write
• JEDEC standard pinout for compatibility
• Available in Plastic SOJ and TSOP(II) packages
• 3.3V ± 0.3V power supply operation
• 4K refresh cycles

Applications

The K4E640812D is suitable for a wide range of applications requiring moderate density DRAM with EDO capabilities:

• Desktop computer systems
• Workstations
• Embedded systems
• Networking equipment
• Telecommunications systems
• Industrial control systems
• Test and measurement equipment
• Consumer electronics
• Low-power portable devices (L-version)

Functional Description

Memory Organization

The K4E640812D organizes its 67,108,864 bits as 8,388,608 addressable words of 8 bits each. The memory array consists of 8,388,608 × 8 cells, accessed through a multiplexed address bus (A0-A12). The device uses a 4K refresh scheme, requiring 4,096 refresh cycles to maintain data integrity.

Refresh Modes

The device supports multiple refresh modes to accommodate different system requirements:

• CAS-before-RAS Refresh: The standard refresh method where CAS is asserted before RAS
• RAS-only Refresh: Alternative refresh method using only RAS
• Hidden Refresh: Allows refresh operations without interrupting data output
• Self Refresh (L-version only): Enables the device to automatically refresh its contents without external control signals, ideal for low-power applications

EDO Mode Operation

The Extended Data Out mode allows the data outputs to remain valid after CAS goes high, enabling the next column address to be accessed while reading the current data. This pipelining effect improves memory bandwidth compared to conventional DRAMs.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (Vcc): -0.5V to +4.6V
• Input Voltage (Vin): -0.5V to Vcc + 0.5V
• Output Voltage (Vout): -0.5V to Vcc + 0.5V
• Operating Temperature: 0°C to +70°C (Commercial)
• Storage Temperature: -55°C to +125°C

Recommended Operating Conditions

• Supply Voltage (Vcc): 3.3V ± 0.3V
• Input High Voltage (Vih): 2.0V min (Vcc = 3.0V)
• Input Low Voltage (Vil): 0.8V max (Vcc = 3.0V)
• Operating Temperature: 0°C to +70°C

DC Characteristics

• Input Leakage Current (Ili): ±1μA max
• Output Leakage Current (Ilo): ±1μA max
• Operating Current (Icc1): TBD mA max (active)
• Standby Current (Icc2): TBD μA max (CMOS level inputs)
• Refresh Current (Icc3): TBD mA max
• Self Refresh Current (Icc4): TBD μA max (L-version only)

AC Characteristics

• RAS Cycle Time (tRC): 110ns min
• RAS Precharge Time (tRP): 70ns min
• CAS Pulse Width (tCAS): 25ns min
• Address Setup Time (tAS): 0ns min
• Address Hold Time (tAH): 10ns min
• Column Address Access Time (tCAA): 50ns max
• Row Address Access Time (tRAA): 60ns max
• Output Enable Access Time (tOEA): 25ns max
• Data-in Setup Time (tDS): 15ns min
• Data-in Hold Time (tDH): 0ns min

Package Information

The K4E640812D is available in two industry-standard package options:

Plastic SOJ (Small Outline J-lead) Package

• Package dimensions: 400mil width, 28-pin configuration
• Lead pitch: 1.27mm
• Package height: 3.81mm max
• Moisture sensitivity level: MSL 3

TSOP(II) (Thin Small Outline Package) Type II

• Package dimensions: 400mil width, 28-pin configuration
• Lead pitch: 0.8mm
• Package height: 1.2mm max
• Moisture sensitivity level: MSL 3

Ordering Information

The device is available in several variants distinguished by speed grade, package type, and power options:

• K4E640812D-XX: Standard version (XX indicates speed grade)
• K4E640812D-LXX: Low-power version with self refresh capability
• Package options: -S (SOJ), -T (TSOP(II))

Quality and Reliability

Samsung Electronics guarantees the quality and reliability of the K4E640812D through:

• 100% production testing
• Burn-in testing on sample basis
• Compliance with JEDEC standards
• ESD protection exceeding 2000V (Human Body Model)
• Latch-up immunity testing

Notes

Samsung Electronics Co., Ltd. reserves the right to change specifications and information contained in this document without prior notice. Users should verify current specifications with the latest datasheet before finalizing designs.