English
Language : 

DS1609 Datasheet, PDF (7/7 Pages) Dallas Semiconductor – Dual Port RAM
DS1609
NOTES:
1. All Voltages are referenced to ground.
2. All pins other than CE, WE, OE, VCC and ground are continuously driven by a feedback latch in order to hold the
inputs at one power supply rail or the other when an input is tristated. The minimum driving impedance presented
to any pin is 50KΩ. If a pin is at a logic low level, this impedance will be pulling the pin to ground. If a pin is at a
logic high level, this impedance will be pulling the pin to VCC.
3. Standby current is measured with outputs open circuited.
4. ICCS1 is measured with all pins within 0.3V of VCC or GND and with CE at a logic high or logic low level.
5. ICCS2 is measured with all pins within 0.3V of VCC or ground and with CE within 0.3V of VCC.
6. ICCS3 is measured with all pins at VCC or ground potential and with CE = VCC. Note that if a pin is floating, the
internal feedback latches will pull all the pins to one power supply rail or the other.
7. Active current is measured with outputs open circuited, and inputs swinging full supply levels with one port reading
and one port writing at 100 ns cycle time. Active currents are a DC average with respect to the number of 0’s and
1’s being read or written.
8. Logic one voltages are specified at a source current of 1 mA.
9. Logic zero voltages are specified at a sink current of 4 mA.
10. Measured with a load as shown in Figure 3.
11. tWP is defined as the time from WE going low to the first of the rising edges of WE and CE.
12. Recovery time is the amount of time control signals must remain high between successive cycles.
13. Typical values are at 25°C.
LOAD SCHEMATIC Figure 3
+5 VOLTS
D.U.T.
680 Ω
1.1KΩ
30 pF
020499 7/7