CY7C274-30WC Cypress Semiconductor Corp, CY7C274-30WC Datasheet - Page 4

• Manufacturer Part Number: CY7C274-30WC
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C274-30WC

• Density: 256Kb
• Access Time (max): 30ns
• Supply Current: 120mA
• Pin Count: 28
• Mounting: Through Hole
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Not Compliant

Switching Waveform
Erasure Characteristics
Wavelengths of light less than 4000 angstroms begin to erase
the CY7C271 and CY7C274 in the windowed package. For
this reason, an opaque label should be placed over the window
if the PROM is exposed to sunlight or fluorescent lighting for
extended periods of time.
The recommended dose of ultraviolet light for erasure is a
wavelength of 2537 angstroms for a minimum dose (UV
intensity
with a 12 mW/cm
imately 35 minutes. The CY7C271 or CY7C274 needs to be within 1
Table 1. CY7C271 Mode Selection
Document #: 38-04008 Rev. *B
OE, CE, CS
Read
Power Down
Output Disable
Output Disable
Program
Program Verify
Program Inhibit
Blank Check
Note:
7.
Mode
CURRENT
ADDRESS
CS
A
O
SUPPLY
0
0
2
- O
and CS
CS
V
A
1
exposure time) of 25 Wsec/cm
CC
[7]
14
2
7
Read or Output Disable
1
2
PREVIOUS DATA VALID
are used on the 7C271 only. OE is used on the 7C274 only.
power rating, the exposure time would be approx-
Other
t
OH
t
2
AA
. For an ultraviolet lamp
A
A
A
A
A
A
A
A
A
A
14
14
14
14
14
14
14
14
14
14
–A
–A
–A
–A
–A
–A
–A
–A
–A
–A
0
0
0
0
0
0
0
0
0
0
DATA VALID
t
PD
t
(t
HZCS(E)
HZOE
VFY
V
V
V
V
CE
V
V
X
X
IHP
IHP
ILP
ILP
IH
IL
)
inch of the lamp during erasure. Permanent damage may result if the
PROM is exposed to high-intensity UV light for an extended period of
time. 7258 Wsec/cm
Programming Modes
Programming support is available from Cypress as well as
from a number of third-party software vendors. For detailed
programming information, including a listing of software
packages, please see the PROM Programming Information
located at the end of this section. Programming algorithms can
be obtained from any Cypress representative.
50%
Pin Function
V
V
IHP
IHP
PGM
CS
V
V
V
V
X
X
IHP
ILP
t
IH
/V
/V
PU
IL
2
ILP
ILP
HIGH Z
2
is the recommended maximum dosage.
t
50%
ACS(E)
(t
POWER-DOWN CONTROLLED BY CE
OE
[8]
)
CS
V
V
V
V
V
V
V
X
X
PP
PP
PP
PP
PP
IH
IL
1
CY7C271
CY7C274
Page 4 of 11
O
High Z
High Z
High Z
High Z
D
O
O
O
D
7
7
7
7
7
7
–O
–D
–O
–D
–O
–O
0
0
0
0
0
0