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AS7C3256A-8

3.3V 32K X 8 CMOS SRAM (Common I / O) Features

March 2005 Preliminary Information
AS7C3256A-8
3.3V 32K X 8 CMOS SRAM (Common I / O) Features
Logic block diagram
VCC GND Input buffer
Pin arrangement
I / O7 Row decoder Sense amp 256 X 128 X 8 Array (262, 144)
OE A11 A9 A8 A13 WE VCC A14 A12 A7 A6 A5 A4 A3
AS7C3256A
Column decoder
WE Control circuit OE CE
Selection guide
-8 Maximum address access time Maximum output enable access time Maximum operating current Maximum CMOS standby current 8 5 60 2 Unit ns ns mA mA
Alliance Semiconductor
AS7C3256A
AS7C3256A-8
Functional description
Absolute maximum ratings
Parameter Voltage on VCC relative to GND Voltage on any pin relative to GND Power dissipation Storage temperature (plastic) Ambient temperature with VCC applied DC current into outputs (low) Symbol Vt1 Vt2 PD Tstg Tbias IOUT Min -0.5 -0.5 - -65 -55 - Max +5.0 VCC + 0.5 1.0 +150 +125 20 Unit V V W
Stresses 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 outside those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
Truth table
CE H L L L WE X H H L OE X H L X High Z High Z DOUT DIN Data Mode Standby (ISB, ISB1) Output disable (ICC) Read (ICC) Write (ICC)
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AS7C3256A-8
Recommended operating conditions
Parameter Supply voltage Input voltage Ambient operating temperature
Symbol VCC VIH VIL commercial TA
Min 3.0 2.0 -0.5 0
Typical 3.3 - - -
Max 3.6 VCC+0.5 0.8 70
DC operating characteristics (over the operating range)1
Operating power supply ICC current ISB Standby power supply current ISB1 VOL VOH
Output voltage
Alliance Semiconductor
AS7C3256A-8
Read cycle (over the operating range)2, 8
-8 Parameter Read cycle time Address access time Chip enable (CE) access time Output enable (OE) access time Output hold from address change CE LOW to output in low Z CE HIGH to output in high Z OE LOW to output in low Z OE HIGH to output in high Z Power up time Power down time Symbol tRC tAA tACE tOE tOH tCLZ tCHZ tOLZ tOHZ tPU tPD Min 8 - - - 3 3 - 0 - 0 - Max - 8 8 5 - - 3 - 3 - 10 Unit ns ns ns ns ns ns ns ns ns ns ns 4 3, 4 3, 4 3, 4 3, 4 3, 4 3, 4 2 2 Notes
Key to switching waveforms
Read waveform 1 (address controlled)2, 5, 6, 8
tRC Address tAA Dout Data valid tOH
Read waveform 2 (CE controlled)2, 5, 7, 8
Alliance Semiconductor
AS7C3256A-8
Write cycle (over the operating range)9
-8 Parameter Write cycle time Chip enable to write end Address setup to write end Address setup time Write pulse width Write recovery time Address hold from end of write Data valid to write end Data hold time Write enable to output in high Z Output active from write end Symbol tWC tCW tAW tAS tWP tWR tAH tDW tDH tWZ tOW Min 8 8 8 0 7 0 0 5 0 - 3 Max - - - - - - - - - 5 - Unit ns ns ns ns ns ns ns ns ns ns ns 3, 4 3, 4 3, 4 Notes
Write waveform 1 (WE controlled)9
tWC tAW Address WE tAS Din tWZ Dout tWP tDW Data valid tOW tWR tDH tAH
Write waveform 2 (CE controlled)9
tAW Address tAS CE tWP WE tWZ Din Dout tDW Data valid tDH tCW tWR tWC tAH
Alliance Semiconductor
AS7C3256A-8
AC test conditions
Output load: see Figure B Input pulse level: GND to 3.0V. See Figure A. Input rise and fall times: 2 ns. See Figure A. Input and output timing reference levels: 1.5V.
+3.3V Dout 350 320 C10 Dout Thevenin equivalent 168
+3.0V GND
+1.72V
Figure A: Input pulse
GND Figure B: Output load
Notes
Alliance Semiconductor
AS7C3256A-8
Package diagrams 28-pin SOJ
28-pin SOJ Min Max in inches A A1 A2 B b c D E E1 E2 e
Seating Plane
28-pin TSOP1
0.050 BSC
1.00 1.20 0.05 0.15 0.91 1.05 0.17 0.27 0.10 0.20 11.70 11.90 0.55 nominal 7.90 8.10 13.20 13.60 0.50 0.70 0° 5°
Alliance Semiconductor
AS7C3256A-8
Ordering information
Package Plastic SOJ, 300 mil TSOP 8x13.4mm
Temperature Commercial Commercial
AS7C3256A-8JC AS7C3256A-8TC
Part numbering system
AS7C 3
Packages:
Alliance Semiconductor
AS7C3256A-8
Alliance Semiconductor Corporation 2575, Augustine Drive, Santa Clara, CA 95054 Tel: 408 - 855 - 4900 Fax: 408 - 855 - 4999 www.alsc.com