W27C02-70 Winbond Electronics, W27C02-70 Datasheet - Page 3

• Manufacturer Part Number: W27C02-70
• Manufacturer: Winbond Electronics

Specifications of W27C02-70

• Density: 2Mb
• Interface Type: Parallel
• Organization: 256Kx8
• Access Time (max): 70ns
• Write Protection: No
• Operating Supply Voltage (typ): 5V
• Package Type: PDIP
• Operating Temp Range: 0C to 70C
• Supply Current: 30mA
• Operating Supply Voltage (min): 4.75V
• Operating Supply Voltage (max): 5.25V
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 32
• Lead Free Status / Rohs Status: Not Compliant

Standby Mode
The standby mode significantly reduces V
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 W27C02 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 (I
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 F ceramic
capacitor connected between its V
should be placed as close as possible to the device. Additionally, for every eight devices, a 4.7 F
electrolytic capacitor should be placed at the array's power supply connection between V
The bulk capacitor will overcome voltage slumps caused by PC board trace inductances.
TABLE OF OPERATING MODES
V
DD
Read
Output Disable
Standby (TTL)
Standby (CMOS)
Program
Program Verify
Program Inhibit
Erase1
Erase2
Erase Verify
Erase Inhibit
Product Identifier -
Manufacturer
Product Identifier -
Device
=5.0V
MODE
5%, Vpp = Vp
E
= V
#CE
V
V
0.3V
V
V
V
V
V
V
V
V
V
V
V
HH
DD
IH
IH
IH
IL
IL
IL
IL
IL
IL
IL
IL
IL
= 12V, V
#OE
V
V
V
V
V
V
DD
V
V
V
X
CP
X
X
X
IH
IL
IL
IL
IL
IL
IH
IH
IH
= V
and Vss. This high frequency, low inherent-inductance capacitor
PE
#PGM
DD
= V
V
V
V
V
V
X
X
X
X
X
X
X
X
IH
IH
IL
IL
IL
current. This mode is entered when #CE high. In standby
CE
= 5.0V , X=V
- 3 -
V
V
V
A0
Addr. = 2AAA (hex)
X
X
X
X
X
X
X
X
X
Second command:
Addr. = 5555 (hex)
IH
IL
IL
First command:
V
V
V
IH
A9
PINS
X
X
X
X
X
X
X
X
X
HH
HH
PE
or V
IL
Publication Release Date: April 11, 2002
ADDR
OTER
SB
X
X
X
X
X
X
X
X
X
X
X
), active current levels (I
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
DD
DD
DD
DD
DD
CP
CP
CP
CE
CE
CE
PE
CE
DD
DD
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
PP
DD
DD
DD
DD
PP
PP
PP
PE
CP
CP
PE
PE
DD
DD
W27C02
D
High Z
High Z
High Z
D
D
High Z
FF (Hex)
AA (Hex)
10 (Hex)
D
High Z
DA (Hex)
85 (Hex)
OUTPUTS
DD
OUT
IN
OUT
OUT
Revision A2
and Vss.
CC
), and