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W27L520 Datasheet, PDF (3/16 Pages) Winbond – 64K X 8 ELECTRICALLY ERASABLE EPROM
Preliminary W27L520
An EPROM's power switching characteristics require careful device decoupling. System designers are
interested in three supply current issues: standby current levels (ISB), active current levels (IDD), and
transient current peaks produced by the falling and rising edges of ALE Transient current magnitudes
depend on the device output's capacitive and inductive loading. Proper decoupling capacitor selection
will suppress transient voltage peaks. Each device should have a
0.1 µF ceramic capacitor connected between its VDD and GND. This high frequency, low inherent-
inductance capacitor should be placed as close as possible to the device. Additionally, for every eight
devices, a 4.7 µF electrolytic capacitor should be placed at the array's power supply connection
between VDD and GND. The bulk capacitor will overcome voltage slumps caused by PC board trace
inductances.
TABLE OF OPERATING MODES
(VPP = 13V, VPE = 13V, VHH = 12V, VDP = 6.5V, VDE = 6.5V, VDD = 3.3V, VDI = 5.0V, X = VIH or VIL)
MODE
ALE OE /VPP
PIN
OTHER ADDRESS
Address Latch Enable
VIH
VIH
X
Read
VIL
VIL
AIN
Output Disable
VIL
VIH
X
Standby
VIH
VIH
AIN
Program
VIH
VPP
AIN
Erase 1
VIH
VPE
A8&A11 = VIL, A9 = VPE,
A10 = VIH, Others = X
Erase 2
VIH
VPE
First command:
Addr. = 5555 (hex)
Secon command:
Addr. = 2AAA (hex)
Product Identifier-
manufacturer
VIL
VIL
A8 = VIL, A9 = VHH, Others = X
Product Identifier-device VIL
VIL
A8 = VIH, A9 = VHH, Others = X
VDD AD[7:0]
VDD A[7:0]
VDD DOUT
VDD High Z
VDD A[7:0]
VDP DIN
VDE X
VDE AA(hex)
VDE 10(hex)
VDI DA(Hex)
VDI 1F(Hex)
Publication Release Date: 4/26/2000
-3-
Revision A2