CY7C291A-293A Datasheet, PDF (6/15 Pages) Cypress Semiconductor – 2K x 8 Reprogrammable PROM

CY7C291A
CY7C292A/CY7C293A
Erasure Characteristics
Wavelengths of light less than 4000 Angstroms begin to erase
these PROMs. 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 inten-
sity x 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.
These PROMs need to be within 1 inch of the lamp during
erasure. Permanent damage may result if the PROM is ex-
posed to high-intensity UV light for an extended period of time.
7258 Wsec/cm² is the recommended maximum dosage.
Programming Information
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.
Table 1. Mode Selection
Read or Output Disable
A₁₀ − A₀
CS₃
Mode
Other
A₁₀ − A₀
PGM
Read
Output Disable^[8]
A₁₀ − A₀
V_IH
A₁₀ − A₀
X
Output Disable
A₁₀ − A₀
X
Output Disable
A₁₀ − A₀
V_IL
Program
A₁₀ − A₀
V_ILP
Program Verify
A₁₀ − A₀
V_IHP
Program Inhibit
A₁₀ − A₀
V_IHP
Intelligent Program
A₁₀ − A₀
V_ILP
Blank Check Zeros
A₁₀ − A₀
V_IHP
Notes:
7. X = “don’t care” but not to exceed V_CC +5%.
8. The power-down mode for the CY7C293A is activated by deselecting CS₁.
Pin Function^[7]
CS₂
VFY
V_IH
X
V_IL
X
V_IHP
V_ILP
V_IHP
V_IHP
V_ILP
CS₁
V_PP
V_IL
V_IH
X
X
V_PP
V_PP
V_PP
V_PP
V_PP
O₇ − O₀
D₇ − D₀
O₇ − O₀
High Z
High Z
High Z
D₇ − D₀
O₇ − O₀
High Z
D₇ − D₀
Zeros
DIP
Top View
A₇
A₆
A₅
A₄
A3
A₂
A₁
A₀
D₀
D₁
D₂
GND
1
24
2
23
3
22
4
7C291A
7C292A
21
5 7C293A ²⁰
6
19
7
18
8
17
9
16
10
15
11
14
12
13
V_CC
A₈
A₉
A₁₀
V_PP
VFY
PGM
D₇
D₆
D₅
D4
D₃
C291A-8
LCC/PLCC (Opaque Only)
Top View
4 3 2 1 28 27 26
A₄ 5
A₃ 6
A_{2 7}
7C291A
25 A10
24 VPP
23 VFY
A_{1 8}
22 PGM
A_{0 9}
21 NC
NC ₁₀ 7C293A
20 D₇
D₀
11
19
121314151617 18
D₆
C291A-9
Figure 1. Programming Pinouts
6