W27E520 Datasheet, PDF (3/16 Pages) Winbond – 64K X 8 ELECTRICALLY ERASABLE EPROM

W27E520
System Considerations
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 = 5.0V, VDI = 5.0V, X = VIH or VIL)
MODE
Address Latch Enable
Read
Output Disable
Standby
Program
Erase 1
Erase 2
Product Identifier-
manufacturer
Product Identifier-device
ALE
VIH
VIL
VIL
/VIH
VIH
VIH
VIH
VIH
VIL
VIL
OE /VPP
VIH
VIL
VIH
VIH
VPP
VPE
VPE
VIL
VIL
PIN
OTHER ADDRESS
AIN
AIN
X
X
AIN
A8&A11 = VIL, A9 = VPE,
A10 = VIH, Others = X
First command:
Addr. = 5555 (hex)
Second command:
Addr. = 2AAA (hex)
A8 = VIL, A9 = VHH, Others = X
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: September 2000
-3-
Revision A2