Description (Continued)
System Considerations
The AT27C512R is available in a choice of industry stand-
ard JEDEC-approved one-time programmable (OTP)
plastic PDIP, PLCC, SOIC, and TSOP packages. All de-
vices feature two-line control (CE, OE) to give designers
the flexibility to prevent bus contention.
Switching between active and standby conditions via the
Chip Enable pin may produce transient voltage excur-
sions. Unless accommodated by the system design, these
transients may exceed data sheet limits, resulting in de-
vice non-conformance. At a minimum, a 0.1 µF high fre-
quency, low inherent inductance, ceramic capacitor
should be utilized for each device. This capacitor should
With 64K byte storage capability, the AT27C512R allows
firmware to be stored reliably and to be accessed by the
system without the delays of mass storage media.
be connected between the V and Ground terminals of
CC
the device, as close to the device as possible. Additionally,
to stabilize the supply voltage level on printed circuit
boards with large EPROM arrays, a 4.7 µF bulk electrolytic
capacitor should be utilized, again connected between the
Atmel’s 27C512R has additional features to ensure high
quality and efficient production use. The Rapid Program-
ming Algorithm reduces the time required to program the
part and guarantees reliable programming. Programming
time is typically only 100 µs/byte. The Integrated Product
Identification Code electronically identifies the device and
manufacturer. This feature is used by industry standard
programming equipment to select the proper program-
ming algorithms and voltages.
V
and Ground terminals. This capacitor should be posi-
CC
tioned as close as possible to the point where the power
supply is connected to the array.
3-136
AT27C512R
ATMEL [ ATMEL ]
