ESD/EMI Forum - Recent Threads

EMI protection for automotive analog input

Alvaro Mart��nez — Thu, 16 May 2013 08:56:24 GMT

Dear all,

We are designing a new ECU which is by now in prototyping phase and have succeeded in all EMC tests except for Bulk Current Injection test. We would like to protect our analog input by adding some elements to reject high frequencies and don't know how to do it.

In the following picture you can see what we have by now. We are thinking of adding a ferrite between the pull-up/pull-down resistors and the RC filter to reject high frequencies above 20MHz. Do you think this is a good idea? Is there any other solution that you could suggest? There is no problem for us to redo any part of the design to include new integrated solutions if necessary.

Thank you very much for you kind support,

Best regards,

alvaro

HDMI 1.4 Receiver Side ESD Protection

Chang-woo YANG — Fri, 05 Apr 2013 07:33:44 GMT

Hello~

I'm searching HDMI 1.4 Receiver Side ESD Protection device, but I cannot find the suitable device.

As I think that TPD12S520 is just support HDMI 1.3, and so I think TPD12S520 is not right device.

Would you please advise to me??

Thanks... C.W. :)

Can TPD12S015A be used for HDMI RX port?

MihirShah — Thu, 11 Apr 2013 05:17:09 GMT

Hi,

As per TPD12S015A datasheet, it is called HDMI Companion chip. Since it has DC-DC step up converter and 5V output, it seems to be for HDMI Transmitter use. But no where in datasheet it is mentioned as to be used only for HDMI TX.

We have used this for HDMI RX port. We have left the HPD pin floating and we have external logic for HPD. We are able to detect the HDMI source connection with this HPD logic. Even the HDMI source is able to read EDID values from our RX port.

We want to be very much sure if we are in right direction and this chip can be used for HDMI RX port. If there is anything related HDMI RX Port compliance which is not available with this TPD12S015A, then we must not use it. Can you help us know about this ?

We also have doubt on internal Pull up resistor 1.75k on SDA_B and SCL_B pins of this chip. The HDMI specifications for Receive port mentions 47k pull up.

Is it valid to use TPD12S015A for HDMI RX ?

Thx,

Mihir

[TPD4S214] RΘjc(Thermal Resistance Junction to Case)

Chang-woo YANG — Mon, 22 Apr 2013 02:48:44 GMT

Hello~

Would you please let me know the RΘjc (Thermal Resistance Junction to Case) of "TPD4S214"??

I'm unable to find these values on "TPD4S214" datasheet.

Thanks... C.W. :)

[TPD13S523] Tj(Max. Junction Temperature)

Chang-woo YANG — Mon, 22 Apr 2013 02:46:56 GMT

Hello~

Would you please let me know the Tj (Max. Junction Temperature)??

I'm unable to find these values on "TPD13S523" datasheet.

Thanks... C.W. :)

TPD4E001 DC offset

fabu — Fri, 19 Apr 2013 02:17:44 GMT

TPD4E001 supports a wide range of supply voltages. I am wondering what is the DC offset value seen at the IO pins?

It should be = 2 diode drops - a zener drop

TPD1E10B09 leakage current

Rachel Coulter — Thu, 03 Jan 2013 20:50:36 GMT

Hi,

For the TPD1E10B09, approximately how much leakage current will occur if 6.6V is applied across the device. Is this documented anywhere?

Regards,

Rachel

Where is pin 1 for TPD3E001?

Amy Garcia — Mon, 25 Mar 2013 18:57:01 GMT

I am using three TPD3E001 in DRY-6 package on my design and the data sheet doesn’t show any marking for pin1.

As Murphy’s law strikes, the CM had 50% chance to put them the wrong way, which of course he did.

The explanation on page 15 of the data sheet is not very helpful.

Please advise where pin1 is. I can debug the board without those but I need to ship fully functional boards in the next few days.

ESD PROTECTION (TPD2S017) chip Input output channel usage clariffication.

Chetan Kumar JC — Mon, 11 Mar 2013 12:40:26 GMT

Dear Sir

I have the following doughts. Please clarify the below doughts.

(1) In our Project we are using TPD2S017 for ESD protection.

(2) In this chip pin no 3 , 4 are Ch1_In, Ch2_In and pin no 1, 6 are Ch1_Out, Ch2_Out respectively (as shown below).

(3) As per the internal circuit diagram of the chip both input and output section internal diagram is same (diagram shown below). So it is possible to use pin no 3and 4 as ouput chanel and pin no 1 and 6 as input channel.

(4) In this chip which channel have to use for host side (either input channel or output chanel) and which chanel have to use for device side.

Thanking you.

DMX 512 transients

JoseM — Fri, 04 Mar 2011 18:11:07 GMT

Hi everybody.

I'm developing a DMX512 receiver and have some doubts about grounding and transients protection.

This is the receiver scheme:

Input and output follow floating topology for DMX receivers.
Vx And Vcc are isolated supplies (each one with its trafo, rectifier, etc).
D2, D3 and D4 are bidirectional transient supressor diodes.
All grounds in the system but XGND are tied to chassis ground.

For transient protection, I've followed this scheme(found in a TI appnote):

It uses a grounded topology, with bus shield tied to system GND, wich is not recommended.
I don't know if I should tie TVS diodes to XGND (as shown in the first image) or should do to bus shield (pin 1).

Thanks

[TPD12S521] backdrive protection

Chang-woo YANG — Mon, 28 Jan 2013 12:28:35 GMT

Hello~

According to TPD12S521 datasheet on page 1, we can find "backdrive protection" feature.

In case of control pins (such as CEC, DDC, HOTPLUG), the internal FET is high ohmic at power-down and therefore disconnects the input from the output. so it is "backdrive protection" feature (as I understood).

But in case of TMDS signals, I don't know how to operate the "backdrive protection" feature, and I don't understand what it means this feature.

Please help me.

Thanks... C.W. :)

Unused pins on ESD protection (TPD3E001)

Tom Moon — Thu, 24 Jan 2013 10:49:23 GMT

Hi,

I am using the TPD3E001 to protect D+/D- of a high speed USB port. I chose the 3 port device instead of the 2 port as the pinout worked better for my routing.

My question is what should I do with the un-used 3rd protected pin? Should I let it float, or would it be a good idea to tie it high/low with a pull up/down?

Thanks in advance!

Tom

TPD4S014 Mission Informations

Luis Filipe Rossi — Thu, 03 Jan 2013 01:55:38 GMT

Hello, i am planning on using TPD4S014 but a few in formations are missing on the datasheet. As my application is real low power i would like to know what is the leakage current on ACK pin when there is no power on VBUS. Also is there any worry about reverse current on VBUSOUT when there is no Power on VBUS? Should i add a blocking diode?

Regards,

How it works when TPD4S014 is going to be in OCP mode.

Jake Kim — Fri, 16 Nov 2012 01:22:14 GMT

Hi Tier.

I've found this device(TPD4S014) has total solution for USB protection.

But, the datasheet has not described about OCP mode.

How it works when it goes into OCP mode. Is it hiccup mode? or do not have this function?

Hope to see your quick answer.

Thanks

TPD4S014 ID PIn Connection

yoshiki hasebe — Tue, 15 Jan 2013 04:10:38 GMT

Dir Sir.

I have a question.

In TPD4S014 , how the ID pin does connected ,if the ID pin is not used?
Please teach me how to connect it.
(floating?, pull down to GND?, pull up to ? etc)

Best regards.

TPD1E10B09 Pin 1,2 Markings

Ryan Andrews — Fri, 10 Aug 2012 16:05:30 GMT

Hi Team,

Can you please help me confirm the part placement orientation/polarity for the TPD1E10B09? Are there any markings on the part to designate pin # 1 vs pin # 2 ?

The customer and I do not see anything definitive mentioned in the datasheets to indicate how to determine pin #s; however, they have noticed a white band across the part, does this indicate Pin 1??

Thanks in advance for your guidance.

Best Regards,

Ryan Andrews - ACAT

Is TPD6F003 good ESD/EMI protection for JTAG?

Andrew Warnock — Mon, 04 Jun 2012 15:17:03 GMT

Quite simply, is the TPD6F003 a good ESD/EMI protection circuit for JTAG? It won't affect speed or cause a problem?

TPD12S521 and HDMI connector chassis GND connections

YILMAZ KIRÇİÇEK — Sun, 02 Dec 2012 02:12:11 GMT

Hi all,

I will use TPD12S521 on my HDMI interface.

As all you know we usually connect shielded connectors (RJ45, USB...) chassis to GND by a ferrit bead, RC, or just R. And the protection devices GND is connected to the connector chassis.

But most of the reference design, HDMI connector chassis had directly connected to the GND.

There is board layout guide on TPD12S521 datasheet but not mention about connector chassis.

What is your idea, should I constitute a TMDS GND plane and connect it to connector chassis, then tie this plane to GND with ferrite bead, or directly connect all of them to GND ?

Best Regards.

TPD12S521 CEC OUT Leakage Current

hideyuki sakai — Thu, 15 Nov 2012 10:10:52 GMT

Figure2 on the datasheet shows the reference curcuit of this device.

Our customer observed over 1.8uA Leakage current , when 5V_SUPPLY is OFF referring

the circuit. This leakage looks to flow from pull-up to inside of chip(maybe 5V_SUPPLY line).

1. Is there a possibility to occur this kind of over leakage current?

2. If there was a possibility, How is the improment method against over leakage.

Best Regards,

ESD PROTECTION

eli — Mon, 12 Nov 2012 16:25:35 GMT

Looking for an ESD Protection Array for AC Signal Data Interface,with I/O capacitance of below 1PF

ibis model

EARNEST ARUJ — Tue, 06 Nov 2012 10:39:06 GMT

I'm simulating an LVDS line in Hyperlynx boardsim .I'm using TPD2E009(differential ESD) at the LVDS line for esd protection. The waveform doesn't look good during simulation ,TI doesn't provide an ibis model for this diode.Could you provide me with the ibis model ?

ESD PROTECTON

eli — Sun, 28 Oct 2012 13:01:10 GMT

please advise recomended replacement to SP724AH from LITTLEFUSE

TPD4E001 Channel Clamp Voltage

Joey Christ — Mon, 22 Oct 2012 20:30:04 GMT

Please explain the "Vc" ("Channel Clamp Voltage") in the electrical characteristics table. What node can reach "Vcc + 25V"? What voltages sum to get the "+25V"?

TPD4S014 Protection voltage

Aska — Mon, 17 Sep 2012 05:48:31 GMT

Hi,

If use this protection IC USB Connector side (Vbus, D +, D-) 12V input voltage

protection whether action? have this kind of protection applications IC?thanks.

TPD12S521 backdrive current/voltage

Joachim Glaess — Tue, 24 Apr 2012 12:11:34 GMT

We plugged another HDMI output to a not powered HDMI output with an TPD12S521 and saw, that the 5V from the 5V_OUT pin (38) can be measured on the 5V_SUPPLY pin (1). In the datasheet on page 6 I_backdrive is given max 5µA. We measured 67mA.

How can we protect our electronics from the HDMI 5V voltage when a cable is plugged wrongly?

Thank you.

Regards,

Joachim