CY7C274-55QMB Cypress Semiconductor Corp, CY7C274-55QMB Datasheet - Page 4

• Manufacturer Part Number: CY7C274-55QMB
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C274-55QMB

• Density: 256Kb
• Organization: 32Kx8
• Interface Type: Parallel
• In System Programmable: In System/External
• Frequency (max): Not RequiredMHz
• Access Time (max): 55ns
• Package Type: LCC
• Reprogramming Technique: UV
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Supply Current: 130mA
• Pin Count: 32
• Mounting: Surface Mount
• Operating Temp Range: -55C to 125C
• Operating Temperature Classification: Military
• Lead Free Status / Rohs Status: Not Compliant

Switching Waveform
Erasure Characteristics
Wavelengths of light less than 4000 angstroms begin to erase
the 7C271 and 7C274 in the windowed package. For this rea-
son, an opaque label should be placed over the window if the
PROM is exposed to sunlight or fluorescent lighting for extend-
ed periods of time.
The recommended dose of ultraviolet light for erasure is a
wavelength of 2537 angstroms for a minimum dose (UV inten-
sity exposure time) of 25 Wsec/cm
12 mW/cm
35 minutes. The 7C271 or 7C274 needs to be within 1 inch of the
Table 1. CY7C271 Mode Selection
Document #: 38-04008 Rev. **
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
2
CS
V
A
1
power rating, the exposure time would be approximately
CC
[7
14
2
7
Read or Output Disable
1
PREVIOUS DATA VALID
are used on the 7C271 only. OE is used on the 7C274 only.
Other
2
t
. For an ultraviolet lamp with a
OH
t
AA
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
)
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 pack-
ages, please see the PROM Programming Information located
at the end of this section. Programming algorithms can be ob-
tained from any Cypress representative.
50%
Pin Function
V
V
IHP
IHP
PGM
V
2
CS
V
V
V
X
X
IHP
is the recommended maximum dosage.
ILP
t
IH
/V
/V
PU
IL
2
ILP
ILP
HIGH Z
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 15
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