M87C257-10C7X Ver la hoja de datos (PDF) - STMicroelectronics
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M87C257-10C7X Datasheet PDF : 13 Pages
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M87C257
Table 9. Programming Mode DC Characteristics (1)
(TA = 25 °C; VCC = 6.25V ± 0.25V; VPP = 12.75V ± 0.25V)
Symbol
Parameter
Test Condition
Min
Max
ILI
Input Leakage Current
VIL ≤ VIN ≤ VIH
±10
ICC
Supply Current
50
IPP
Program Current
E = VIL
50
VIL
Input Low Voltage
–0.3
0.8
VIH
Input High Voltage
2
VCC + 0.5
VOL
Output Low Voltage
IOL = 2.1mA
0.4
VOH
Output High Voltage TTL
IOH = –1mA
VCC -0.8V
VID
A9 Voltage
11.5
Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP.
12.5
Unit
µA
mA
mA
V
V
V
V
V
Table 10. Programming Mode AC Characteristics (1)
(TA = 25 °C; VCC = 6.25V ± 0.25V; VPP = 12.75V ± 0.25V)
Symbol Alt
Parameter
Test Condition
Min
tAVEL
tAS Address Valid to Chip Enable Low
2
tQVEL
tDS Input Valid to Chip Enable Low
2
tVPHEL
tVPS VPP High to Chip Enable Low
2
tVCHEL
tVCS VCC High to Chip Enable Low
2
tELEH
tPW Chip Enable Program Pulse Width
95
tEHQX
tDH Chip Enable High to Input Transition
2
tQXGL
tOES Input Transition to Output Enable Low
2
tGLQV
tOE Output Enable Low to Output Valid
tGHQZ
tDFP Output Enable High to Output Hi-Z
0
tGHAX
tAH Output Enable High to Address Transition
0
Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP
Max
105
100
130
Unit
µs
µs
µs
µs
µs
µs
µs
ns
ns
ns
Programming
When delivered (and after each erasure for UV
EPROM), all bits of the M87C257 are in the "1"
state. Data is introduced by selectively program-
ming "0"s into the desired bit locations. Although
only "0"s will be programmed, both "1"s and "0"s
can be present in the data word. The only way to
change a "0" to a "1" is by die exposition to ultra-
violet light (UV EPROM). The M87C257 is in the
programming mode when VPP input is at 12.75V, G
is at VIH and E is pulsed to VIL. The data to be
programmed is applied to 8 bits in parallel to the
data output pins. The levels required for the ad-
dress and data inputs are TTL. VCC is specified to
be 6.25 V ± 0.25 V.
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