If the U631H16 is in a WRITE state at the end of power
up RECALL, the SRAM data will be corrupted.
To help avoid this situation, a 10 KΩ resistor should be
connected between W and VCC.
The U631H16 offers hardware protection against inad-
vertent STORE operation through VCC sense.
For VCC < VSWITCH the software initiated STORE opera-
tion will be inhibited.
Low Average Active Power
The U631H16 has been designed to draw significantly
less power when E is LOW (chip enabled) but the
access cycle time is longer than 55 ns.
When E is HIGH the chip consumes only standby cur-
The overall average current drawn by the part depends
on the following items:
1. CMOS or TTL input levels
2. the time during which the chip is disabled (E HIGH)
3. the cycle time for accesses (E LOW)
4. the ratio of READs to WRITEs
5. the operating temperature
6. the VCC level
The information describes the type of component and shall not be considered as assured characteristics. Terms of
delivery and rights to change design reserved.
March 31, 2006
STK Control #ML0042