HEDS-5505F06,Top sales HEDS-5505F06,HEDS-5505F06 DATASHEET -ICSTOCK

PARAMETER		TEST CONDITION	MIN	TYP	MAX	UNIT
Upper Threshold Voltage	VUPH	Tc=25 0C		2.90		V
Lower Threshold Voltage	VUPL	Tc=25 0C		2.53		V
Hysteresis (VUPH -VUPL)	VHYS	Tc=25 0C		O37		V

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HEDS-5505F06 datasheet

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HEDS-5505F06 price

Notes : 1. -75 0nly specify a maximum value of 3.5pF
2. -75 0nly specify a maximum value of 3.8pF
3. -75 0nly specify a maximum value of 6.OpF
HEDS-5505F06 pdf

This design assumes that the PGA Am29030 proces-
sor's Scalable Clocking W feature is used, resulting in a
32-MHz processor with a 16-MHz external memory and
PCI bus interface. The worst-case timing in this design
then occu rs in the memory system around a single-cycle
read at 16 MHz. The delay must be set at 20 ns for the
CAS pulse generation while 12 ns is the best time of a
MACH220 device for the combinatorial delay, making
CAS fall at 32 ns into the cycle. CAS access time is 20
ns. A set up of 9 ns makes an access time of61 ns for a
62.5-ns cycle at 16 MHz. If additional setup or CAS ac-
cess time is needed, then the RAS/CAS decode can be
accomplished in a separate, faster decode PAL device.
The DELAY signal from the delay line can be used in this
PAL device, with the other state lines going to the faster
decode PAL device. Additionally, faster address multi-
plexers can be used,such as 74F orAS parts, instead of
the 74LS157s. This reduces the delay from 12 ns t0 6 ns
and decreases the delay line requirement t0 15 ns, gain-
ing an additional 5 ns on CAS access. Use ofthese fast-
er 74F/AS157s then requires 33-ohm series dampening
resistors before the DRAMs.