TSS721A: This IC is not communicating with Micro-controller

Archin Jain

Part Number: TSS721A

Tool/software:

Hi,

I am using this M-Bus slave IC. As per the below allachment, I am giving the Tx pin output (of IC) to the photo-coupler(H11L1) through the PNP transistor. At the outout side of Photo-transistor, always high signal is appearing and it is not getting low even after switching at Tx pin of IC can be seen. Please look this issue.

Also please share the maximum output current of VDD pin pf IC in below condition:

1. RIS - 50 ohm

2. SC - 100 nF

3. RIDD - 15 kohm (30 khom also tried)

4. STC - 220 uF.

7 months ago

0 Archin Jain 7 months ago

Prodigy 60 points

Also want to know that this VDD current can be increase or not as our requirement is >2mA??

0 Archin Jain 7 months ago in reply to Archin Jain

Prodigy 60 points

I did not get the reply from TI as its already been 2 days.

I am waiting the response from the TI.

0 Eric Hackett 7 months ago in reply to Archin Jain

TI__Guru 74282 points

Archin,

Just to understand your issue: the TX pin of the transceiver is switching, but the output of the photodiode is not switching, is that correct? Can you share the specification of the photodiode? It sounds like the TI device is working correctly, but may not be driving the photodiode's thresholds for proper low and high logic signals.

I'm still looking into the VDD current question.

Regards,

Eric Hackett

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TSS721A: This IC is not communicating with Micro-controller