74VHCT257A(2004) 查看數據表（PDF） - STMicroelectronics

零件编号

产品描述 (功能)

比赛名单

74VHCT257A
(Rev.:2004)

QUAD 2 CHANNEL MULTIPLEXER (3-STATE)

STMicroelectronics 

74VHCT257A

Figure 4: Test Circuit

tPLH, tPHL

tPZL, tPLZ

tPZH, tPHZ

TEST

SWITCH

Open

VCC

GND

CL =15/ 50pF or equivalent (includes jig and probe capacitance)

RL = R1 = 1KΩ or equivalent

RT = ZOUT of pulse generator (typically 50Ω)

Figure 5: Waveform - Propagation Delays For Inverting Conditions (f=1MHz; 50% duty cycle)

6/13

Share Link: