ZHCSQA7C December 1982 – March 2022 SN54HC257 , SN74HC258
PRODUCTION DATA
请参考 PDF 数据表获取器件具体的封装图。
tpd is the maximum between tPLH and tPHL
tt is the maximum between tTLH and tTHL
A. CL includes probe and test-fixture capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low
except when diabled by the output control.
Waveform 2
is for an output with internal conditions such that the output is high except when
diabled by the output control.
C. Phase relationships between waveforms were chosen arbitrarily. All input pulses are supplied by generators having the following charactersitics: PRR ≤ 1 MHz, ZO = 50 Ω, tr = 6 ns, tf = 6 ns.
D. The outputs are measured one at a time with one input transition per measurement.
E. tPLZ and tPHZ are the same as tdis.
F. tPZL and tPZH are the same as ten.