6

M65608E

4151I–AERO–03/04

AC Parameters

AC Test Conditions

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 ensure data

retention:

1.

During data retention chip select CS1 must be held high within VCC to VCC -

0.2V or, chip select CS2 must be held down within GND to GND +0.2V.

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 CS1 and OE must be kept between

VCC + 0.3V and 70% of VCC, or with CS2 between GND and GND -0.3V.

4.

The RAM can begin operation > TR ns after VCC reaches the minimum opera-

tion voltages (4.5V).

Timing

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

Input Rise/Fall Times: ...............................5 ns

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

Output loading IOL/IOH (see Figure 1 and Figure 2)+30 pF

Figure 1

Figure 2

Figure 3