RTOS/GD75232: GD75232

Hugo Wang

Expert 1525 points

Part Number: GD75232

Tool/software: TI-RTOS

Hi Sirs

I have two questions about GD75232 and schematics as below.

Q1 Step1. System on, there is pulse at RTS# pin. (input and output both)

Q1 Step2. We isolate -12V and step1 behavior not happened.

Q2 Step1. We see GD75232 maybe has leakage issue and cause power source has twice rising.

Q2 Step2. We isolate D38/D44 or GD75232 and step1 behavior not happened.

If you have any think and suggestions about these questions, please kindly help to share with me. Thank you a lot.

over 6 years ago

0 Hao L over 6 years ago

TI__Mastermind 25705 points

Hugo,

Q1. When you power up the device, are you aware that there is a sequence need to follow?

Q2. Do you mean the leakage happened on VDD pin? Was it also happening during power ramping up? Can you estimate how much the leakage was? Can you also give a little bit of more details on 'twice rising'?

Regards,

Hao

0 Hugo Wang over 6 years ago in reply to Hao L

Expert 1525 points

Hi Hao sir

Q1. We had followed sequence in spec and the results is the same.

Q2. it's not power leakage. The root cause is RTS pin leakage SIO pin and cause RTS pin twice rising as below.

CH1 is GD75232 input side. CH2 is GD75232 output side(connector).

0 Hao L over 6 years ago in reply to Hugo Wang

TI__Mastermind 25705 points

Hugo,

Can you check how to drive the UART1_RTS#? Do you think it's possible that it has current limiting? Because the input stage is BJT based, Iil is 1.6mA when Vi=0V.

Regards,

0 Hao L over 6 years ago in reply to Hao L

TI__Mastermind 25705 points

Hugo,
You can refer to this post for similar observation on DA pin when the device is powered up. Please let me know if you still have question. e2e.ti.com/.../609497

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RTOS/GD75232: GD75232