System considerations, Block diagram – Rainbow Electronics AT27BV4096 User Manual

Page 2

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AT27BV4096

2

Atmel’s innovative design techniques provide fast speeds
that rival 5V parts while keeping the low power consump-
tion of a 3V supply. At V

CC

= 2.7V, any word can be

accessed in less than 120 ns. With a typical power dissipa-
t i o n o f o n l y 1 8 m W a t 5 M H z a n d V

C C

= 3 V , t h e

AT27BV4096 consumes less than one fifth the power of a
standard 5V EPROM.

Standby mode supply current is typically less than 1

µ

A at

3V. The AT27BV4096 simplifies system design and
stretches battery lifetime even further by eliminating the
need for power supply regulation.

The AT27BV4096 is available in industry standard JEDEC-
approved one-time programmable (OTP) plastic PLCC and
TSOP packages. All devices feature two-line control (CE,
OE) to give designers the flexibility to prevent bus
contention.

The AT27BV4096 operating with V

CC

at 3.0V produces TTL

level outputs that are compatible with standard TTL logic
devices operating at V

CC

= 5.0V. At V

CC

= 2.7V, the part is

compatible with JEDEC approved low voltage battery oper-
ation (LVBO) interface specifications. The device is also
capable of standard 5-volt operation making it ideally suited
for dual supply range systems or card products that are
pluggable in both 3-volt and 5-volt hosts.

Atmel’s AT27BV4096 has additional features to ensure
high quality and efficient production use. The Rapid™ Pro-

gramming Algorithm reduces the time required to program
the part and guarantees reliable programming. Program-
ming time is typically only 100

µ

s/word. The Integrated

Product Identification Code electronically identifies the
device and manufacturer. This feature is used by industry
standard programming equipment to select the proper pro-
gramming algorithms and voltages. The AT27BV4096 pro-
grams exactly the same way as a standard 5V AT27C4096
and uses the same programming equipment.

System Considerations

Switching between active and standby conditions via the
Chip Enable pin may produce transient voltage excursions.
Unless accommodated by the system design, these tran-
sients may exceed data sheet limits, resulting in device
non-conformance. At a minimum, a 0.1

µ

F high frequency,

low inherent inductance, ceramic capacitor should be uti-
lized for each device. This capacitor should be connected
between the V

CC

and Ground terminals of 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

µ

F bulk electrolytic capacitor should

be utilized, again connected between the V

CC

and Ground

terminals. This capacitor should be positioned as close as
possible to the point where the power supply is connected
to the array.

Block Diagram

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