參數(shù)資料
型號(hào)： HD74AC
廠商： Hitachi,Ltd.
英文描述： HD74AC Series Common Information
中文描述： HD74AC系列通用信息
文件頁(yè)數(shù)： 25/52頁(yè)
文件大小： 220K
代理商： HD74AC
Definition of Specifications
24
3.2 Test Conditions
Figure 2 describes the input signal voltage levels to be used when testing FACT circuits. The AC test
conditions follow industry convention requiring V
IN
to range from 0 V for a logic low to 3.0 V for a logic
high for HD74ACT devices and 0 V to V
CC
for HD74AC devices. The DC parameters are normally tested
with V
IN
at guaranteed input levels, that is V
IH
to V
IL
(see tables 3 and 4 for details). Care must be taken to
adequately decouple these high performance parts and to protect the test signals from electrical noise. In an
electrically noisy environment, (e.g., a tester and handlder not specifically designed for high-speed work),
DC input levels may need to be adjusted to increase the noise margin to allow for the extra noise in the
tester which would not be see in a system.
Noise immunity testing is performed by raising V
IN
to the nominal supply voltage of 5.0 V then dropping it
to a level corresponding to V
IH
, and then raising it again to the 5.0 V level. Noise tests can also be
performed on the V
IL
characteristics by raising V
IN
from 0 V to V
IL
, then returning it to 0 V. Both V
IH
and
V
IL
noise immunity tests should not induce a switch condition on the appropriate outputs of the FACT
device.
Good high-frequency wiring practices should be used in constructing test jigs. Leads on the load capacitor
should be as short as possible to minimize ripples on the output waveform transitions and to minimize
undershoot. Generous ground metal (preferably a ground plane) should be used for the same reasons. A
V
CC
bypass capacitor should be provided at the test socket, also with minimum lead lengths.
3.3 Rise and Fall Times
Input signals should have rise and fall times of 3.0 ns and signal swing of 0 V to 3.0 V for HD74ACT
devices or 0 V to V
CC
for HD74ACT devices. Rise and fall times less than or equal to 1 ns should be used
for testing f
max
or pulse widths.
CMOS devices, including, 4000 Series CMOS, HC, HCT and FACT families, tend to oscillate when the
input rise and fall times become lengthy. As a direct result of its increased performance, FACT devices can
be more sensitive to slow input rise and fall times than other lower performance technologies.
It is important to understand why this oscillation occurs. Consider the outputs, where the problem is
initiated. Usually, CMOS outputs drive capacitive loads with low DC leakage. When the output changes
from a high level to a low level, or from a low level to a high level, this capacitance has to be charged or
discharged. With the present high performance technologies, this charging or discharging takes place in a
very short time, typically 2-3 ns. The requirement to charge or discharge the capacitive loads quickly
creates a condition where the instantaneous current change through the output structure is quite high. A
voltage is generated across the V
CC
or ground leads inside the package due to the inductance of these leads.
The internal ground of the chip will change in reference to the outside world become of this induced
voltage.
相關(guān)PDF資料
PDF描述
HD74ALVC162244 16-bit Buffer / Driver with 3-state Outputs(帶三態(tài)輸出的16位緩沖器/驅(qū)動(dòng)器)
HD74ALVC162334 16-bit Universal Bus Driver with 3-state Outputs(帶三態(tài)輸出的16位通用總線驅(qū)動(dòng)器)
HD74ALVC16244 16-bit Buffer / Driver with 3-state Outputs(帶三態(tài)輸出的16位緩沖器/驅(qū)動(dòng)器)
HD74ALVC162831 1-bit to 4-bit Address Register / Driver with 3-state Outputs(三態(tài)輸出的1位-4位地址寄存器/驅(qū)動(dòng)器)
HD74ALVC162834A 1-Of-8 Data Selectors/Multiplexers 16-CDIP -55 to 125
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HD74AC00 制造商:HITACHI 制造商全稱:Hitachi Semiconductor 功能描述:Quad 2-Input NAND Gate
HD74AC00FP 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Quad 2-input NAND Gate
HD74AC00FPEL 制造商:RENESAS 制造商全稱:Renesas Technology Corp 功能描述:Quad 2-Input NAND Gate
HD74AC00P 制造商:RENESAS 制造商全稱:Renesas Technology Corp 功能描述:Quad 2-Input NAND Gate
HD74AC00RPEL 制造商:RENESAS 制造商全稱:Renesas Technology Corp 功能描述:Quad 2-Input NAND Gate
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*