SN74LVC8T245-Q1:整个总成件不能点亮，确认芯片VCC-GND短路，主控板数据信号通道无输出 IC电源对地短路

Kevin Wei

Prodigy 10 points

Part Number: SN74LVC8T245-Q1

Tool/software:

您好整个总成件不能点亮，确认芯片VCC-GND短路，主控板数据信号通道无输出 IC电源对地短路是什么原因造成的如下是相关电路图

谢谢

4 months ago

0 Jack Guan 4 months ago

TI__Mastermind 44191 points

Hey Kevin,

I see no immediate issues on the schematic. Can we test to see if there are any shorts/ continuity between the pins? How many devices has this issue been seen in, and what is the measured voltage at VCCA/ VCCB and OE pin during time of testing? What is the voltage of VLED?
Regards,

Jack

0 Kevin Wei 4 months ago in reply to Jack Guan

Prodigy 10 points

There are two questions respectively 1 VCCA-OE1.24V, VCCB-OEShort circuit 2 VCCA-OE1.487V，VCCB-OE The voltage rose from 2.2V to 3.3V

+1 Jack Guan 4 months ago in reply to Kevin Wei

TI__Mastermind 44191 points

Hi Kevin,

I am not sure I understand, can you please elaborate? The schematic suggests that OE is tied to GND to be 0V, though you are describing case 1 and case 2 with 1.24V and 1.487V applied to OE?

Regards,

Jack

0 Kevin Wei 4 months ago in reply to Jack Guan

Prodigy 10 points

The data I measured with the multimeter are VCCA-OE1.487V and VCCB-OE The voltage rose from 2.2V to 3.3V Obviously, this test result is wrong I measured that the data VCCA-OE of other chips is higher than this voltage Please ignore question 1: VCCA-OE1.24V, VCCB-OEShort circuit Thanks