M27C405-100B6TR STMICROELECTRONICS [STMicroelectronics], M27C405-100B6TR Datasheet - Page 8

• Manufacturer Part Number: M27C405-100B6TR
• Description: 4 Mbit 512Kb x 8 OTP EPROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M27C405
Figure 6. Programming and Verify Modes AC Waveforms
System Considerations
The power switching characteristics of Advanced
CMOS OTP EPROMs require careful decoupling of
the devices. The supply current, I
segments that are of interest to the system de-
signer : the standby current level, the active current
level, and transient current peaks that are pro-
duced by the falling and rising edges of E. The
magnitude of the transient current peaks is de-
pendent on the capacitive and inductive loading of
the device at the output.
The associated transient voltage peaks can be
suppressed by complying with the two line output
control and by properly selected decoupling ca-
pacitors. It is recommended that a 0.1 F ceramic
capacitor be used on every device between V
and V
of low inherent inductance and should be placed
as close to the device as possible. In addition, a
8/15
SS
. This should be a high frequencycapacitor
V CC
A0-A18
Q0-Q7
V PP
E
G
tVCHEL
tVPHEL
tQVEL
tAVPL
tELEH
DATA IN
CC
PROGRAM
, has three
CC
VALID
tEHQX
4.7 F bulk electrolytic capacitor should be used
between V
bulk capacitor should be located near the power
supply connection point.The purpose of the bulk
capacitor is to overcome the voltage drop caused
by the inductive effects of PCB traces.
Programming
When delivered, all bits of the M27C405 are in the
’1’ state. Datais introducedby 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 M27C405 is in
the programming mode when V
12.75V,G is at V
to be programmed is applied to 8 bits in parallel to
the data output pins. The levels required for the
address and data inputs are TTL. V
to be 6.25V
tQXGL
VERIFY
tGLQV
DATA OUT
CC
and V
0.25V.
IH
and E is pulsed to V
SS
for every eight devices. The
tGHQZ
tGHAX
AI00725
PP
CC
input is at
IL
is specified
. The data