W3E32M64SA-XBX
10
White Electronic Designs Corporation (602) 437-1520 www.whiteedc.com
White Electronic Designs
December 2007
Rev. 1
REFRESH command is initiated like an AUTO REFRESH
command except CKE is disabled (LOW). The DLL is
automatically disabled upon entering SELF REFRESH
and is automatically enabled upon exiting SELF REFRESH
(200 clock cycles must then occur before a READ
command can be issued). Input signals except CKE are
“Don’t Care” during SELF REFRESH. VREF voltage is also
required for the full duration of SELF REFRESH.
The procedure for exiting self refresh requires a sequence
of commands. First, CK and CK# must be stable prior
ABSOLUTE MAXIMUM RATINGS
Parameter
Unit
Voltage on VCC, VCCQ Supply relative to Vss
-1 to 3.6
V
Voltage on I/O pins relative to VSS
-1 to 3.6
V
Operating Temperature TA (Mil)
-55 to +125
°C
Operating Temperature TA (Ind)
-40 to +85
°C
Storage Temperature, Plastic
-55 to +125
°C
NOTE: Stress greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of
the device at these or any other conditions greater than those indicated in the operational sections of this specication is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
CAPACITANCE (NOTE 13)
Parameter
Symbol
Max
Unit
Input Capacitance: CLK
CI1
8
pF
Addresses, BA0-1 Input Capacitance
CA
22
pF
Input Capacitance: All other input-only pins
CI2
10
pF
Input/Output Capacitance: I/Os
CIO
10
pF
BGA THERMAL RESISTANCE
Description
Symbol
Max
Units
Notes
Junction to Ambient (No Airow)
Theta JA
14.1
°C/W
1
Junction to Ball
Theta JB
10.0
°C/W
1
Junction to Case (Top)
Theta JC
5.2
°C/W
1
NOTE 1: Refer to "PBGA Thermal Resistance Correlation" Application Note at www.whiteedc.com in the application notes section for modeling conditions.
to CKE going back HIGH. Once CKE is HIGH, the DDR
SDRAM must have NOP commands issued for tXSNR,
because time is required for the completion of any internal
refresh in progress.
A simple algorithm for meeting both refresh and DLL
requirements is to apply NOPs for tXSNR time, then a DLL
Reset and NOPs for 200 additional clock cycles before
applying any other command.
* Self refresh available in commercial and industrial temperatures only.