7

AT60142E/ET

4156F–AERO–06/04

AC Characteristics

Temperature Range:................................................ -55 +125

°C

Supply Voltage:........................................................ 3.3 +0.3V

Input Pulse Levels: .................................................. GND to 3.0V

Input Rise and Fall Times:....................................... 3ns (10 - 90%)

Input and Output Timing Reference Levels: ............ 1.5V

VRef Capacitor: ....................................................... 10

µF

Figure 1. AC Test Loads Waveforms

Data Retention Mode

Atmel CMOS RAM's are designed with battery backup in mind. Data retention voltage

and supply current are guaranteed over temperature. The following rules insure data

retention:

1.

2.

Output Enable (OE) should be held high to keep the RAM outputs high imped-

ance, minimizing power dissipation.

3.

During power-up and power-down transitions CS and OE must be kept between

4.

The RAM can begin operation > t

voltages (3V).

Figure 2. Data Retention Timing