W27L02 Datasheet, PDF (3/15 Pages) Winbond – 256K X 8 ELECTRIC ALLY ERASABLE EPROM

W27L02
Standby Mode
The standby mode significantly reduces VDD current. This mode is entered when #CE high. In standby
mode, all outputs are in a high impedance state, independent of #OE and #PGM.
Two-line Output Control
Since EPROMs are often used in large memory arrays, the W27L02 provides two control inputs for
multiple memory connections. Two-line control provides for lowest possible memory power dissipation
and ensures that data bus contention will not occur.
System Considerations
EPROM power switching characteristics require careful device decoupling. System designers are
concerned with three supply current issues: standby current levels (ISB), active current levels (ICC), and
transient current peaks produced by the falling and rising edges of #CE. Transient current magnitudes
depend on the device output's capacitive and inductive loading. Two-line control and proper decoupling
capacitor selection will suppress transient voltage peaks. Each device should have a 0.1 µF ceramic
capacitor connected between its VDD and Vss. 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 Vss.
The bulk capacitor will overcome voltage slumps caused by PC board trace inductances.
Table of Operating Modes
VDD = 3.3V ±10%, Vpp = VpE = VHH = 12V, VCP = VPE = VCE = 5V, X = VIH or VIL
MODE
Read
Output Disable
Standby (TTL)
Standby (CMOS)
Program
Program Verify
Program Inhibit
Erase1
Erase2
Erase Verify
Erase Inhibit
Product Identifier -
Manufacturer
Product Identifier -
Device
#CE
VIL
VIL
VIH
VDD
±0.3V
VIL
VIL
VIH
VIL
VIL
VIL
VIH
VIL
#OE
VIL
VIH
X
X
VIH
VIL
X
VIH
VIH
VIL
X
VIL
#PGM
X
X
X
X
VIL
VIH
X
VIL
VIL
VIH
X
X
PINS
A0
A9
OTER
ADDR
VDD
VPP
OUTPUTS
XX
X
VDD VDD DOUT
XX
X
VDD VDD High Z
XX
X
VDD VDD High Z
XX
X
VDD VDD High Z
XX
X
XX
X
XX
X
VIL VPE
First command:
Addr. = 5555 (hex)
Second command:
Addr. = 2AAA (hex)
XX
X
XX
X
VCP VPP DIN
VCP VPP DOUT
VCP VPP High Z
VCE VPE FF (Hex)
VCE VCP AA (Hex)
VCE VCP 10 (Hex)
VPE VPP DOUT
VCE VPE High Z
VIL VHH
X
VDD VDD DA (Hex)
VIL
VIL
X
VIH VHH
X
VDD VDD 85 (Hex)
Publication Release Date: February 20, 2003
-3-
Revision A3