1 - Al Kossow's Bitsavers

TMS4256, TMS4257262,144-8IT DYNAMIC RANDOM-ACCESS MEMORIESelectrical characteristics over full ranges of recommended operating conditions (unless otherwise noted)TMS4256-10TMS4256-12TESTPARAMETER TMS4257-10 TMS4257-12 UNITCONDITIONSMIN Typt MAX MIN Typt MAXVOH High-level output voltage 10H = -5 mA 2.4 2.4 VVOL Low-level output voltage 10L = 4.2 mA 0.4 0.4 VII Input current (leakage)VI=O V to 5.8 V, VOO=5 V,All other pins = 0 V to 5.8 V±10 ±10 I'AVo = 0 V to 5.5 V,10 Output current (leakage) VOO = 5 V, ±10 ±10 I'ACAS high10D1Average operating currentduring read or write cycletc = minimum cycle 75 TBO 65 TBO mA1002 Standby currentAfter 1 memory cycle,RAS and CAS hightc = minimum cycle,2.55 2.5 5 mA1003 Average refresh current RAS low, 60 TBO 50 TBO mACAS hightc(P) = minimum cycle, \1004 Average page-mode current RAS low, 50 TBO 40 TBO mACAS cyclingtc(N) = minimum cycle,1005 Average nibble-mode current RAS low. 45 TBO 35 TBO mACAS cyclingt All typical values are at T A = 25°C and nominal supply voltages.TMS4256-15 TMS4256-20TESTPARAMETER TMS4257-15 TMS4257-20 UNITCONDITIONSMIN Typt MAX MIN Typt MAXVOH High-level output voltage IOH = -5 mA 2.4 2.4 VVOL Low-level output voltage 10L = 4.2 mA 0.4 0.4 VII Input current (leakage)VI=O V to 5.8 V. VDD=5 V,All other pins = 0 V to 5.8 V±10 ± 10 I'AVo = 0 V to 5.5 V,10 Output current (leakage) VOO = 5 V, ±10 ±10 I'ACAS high1001Average operating currentduring read or write cycle1002 Standby currenttc = minimum cycle 55 TBO 45 TBO mAAfter 1 memory cycle,RAS and CAS hightc = minimum cycle,2.5 5 2.5 5 mA1003 Average refresh current RAS low, 45 TBO 35 TBO mACAS hightc(P) = minimum cycle,1004 Average page-mode current RAS low, 35 TBO 25 TBO mACAS cyclingtc(N) = minimum cycle,1005 Average nibble-mode current RAS low. 30 TBO 20 TBO mACAS cyclingU)Q)o-S;Q)c......oc.c.::::sen>-...oEQ)~"Cr::::m~«a:o-Emr::::>-Ct All typical values are at T A = 25°C and nominal supply voltages.TEXASINSTRUMENTSPOST OFFICE BOX 225012 • DALLAS. TEXAS 752654-67