CY7C271A Datasheet, PDF (4/10 Pages) Cypress Semiconductor – 32K x 8 Power Switched and Reprogrammable PROM

CY7C271A
Switching Waveform
I_CC
t_PU
CE
CS₂
CS₁
A₀ - A₁₄
O₀ - O₇
t_ACE
ADDRA
t_AA
DATA A
t_PD
ACTIVE
INACTIVE
ACTIVE
ADDRB
t_AA
t_HZCS
DATA B
t_ACS
t_OH
t_HZCE
DATA B
Erasure Characteristics
Wavelengths of light less than 4000 Angstroms begin to erase
the CY7C271A 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 multiplied by exposure time) of 25 Wsec/cm². For an
ultraviolet lamp with a 12 mW/cm² power rating, the exposure
time would be approximately 35 minutes. The CY7C271A
needs to be within 1 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/cm² is the recommended maximum dosage.
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.
Table 1. Programming Electrical Characteristics
Parameter
Description
V_PP
I_PP
V_IHP
V_ILP
V_CCP
Programming Power Supply
Programming Supply Current
Programming Input Voltage HIGH
Programming Input Voltage LOW
Programming V_CC
Min.
12.5
3.0
–0.5
6.0
Max.
13
50
V_CC
0.4
6.5
Unit
V
mA
V
V
V
Document #: 38-04013 Rev. *B
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