Features

? Aerospace-Level Product

? 2.0 clock Latency with DLL on

? 1.0 clock Latency with DLL off

? Optional DLL-controlled output timing

? Can be operated with DLL on or off

? Simultaneous Read and Write SigmaQuad? Interface

? JEDEC-standard pinout and package

? Dual Double Data Rate interface

? Byte Write controls sampled at data-in time

? Burst of 4 Read and Write

? Dual-Range On-Die Termination (ODT) on Data (D), Byte

Write (BW), and Clock (K, K) inputs

? 1.8 V +100/–100 mV core power supply

? 1.5 V or 1.8 V HSTL Interface

? Pipelined read operation

? Fully coherent read and write pipelines

? ZQ pin for programmable output drive strength

? Data Valid Pin (QVLD) Support

? IEEE 1149.1 JTAG-compliant Boundary Scan

? 165-bump Ceramic Column Grid Array (CCGA) and

165-bump Land Grid Array (LGA) packages

Radiation Performance

? Total Ionizing Dose (TID) > 100krads(Si)

? Single Event Latchup Immunity > 77.3 MeV.cm2

/mg (125?C)

SigmaQuad? Family Overview

The GS82612DT19/37, GS81332DT19/37, and

GS8692DT19/37 are built in compliance with the SigmaQuadII+ SRAM pinout standard for Separate I/O synchronous

SRAMs. They are 301,989,888-bit (288Mb), 150,994,944-bit

(144Mb), and 75,497,472-bit (72Mb) SRAMs. These

SigmaQuad SRAMs are just one element in a family of low

power, low voltage HSTL I/O SRAMs designed to operate at

the speeds needed to implement economical high performance

networking systems.

Clocking and Addressing Schemes

The Rad-Hard SigmaQuad-II+ SRAMs are synchronous

devices. They employ two input register clock inputs, K and K.

K and K are independent single-ended clock inputs, not

differential inputs to a single differential clock input buffer.

Each internal read and write operation in a SigmaQuad-II+ B4

RAM is four times wider than the device I/O bus. An input

data bus de-multiplexer is used to accumulate incoming data

before it is simultaneously written to the memory array. An

output data multiplexer is used to capture the data produced

from a single memory array read and then route it to the

appropriate output drivers as needed. Therefore, the address

field of a SigmaQuad-II+ B4 RAM is always two address pins

less than the advertised index depth (e.g., the 16M x 18 has a

4M addressable index).