Automotive Forum - Recent Threads

TL720M05-Q1 Question about Input Voltage Drop

HIDE — Tue, 18 Jun 2013 09:02:23 GMT

Hi,

I have some questions about Input Voltage Drop on TL720M05-Q1.

This application is connecting 16 LDO Units in parallel like below;

(Power: +17V)

(1) Power ON with connecting 16 LDO units, but input voltage fall to 3V and all of units don't work.

(2) Remove LDO unit one by one. When connecting 6 LDO Units, input voltage raise to 14V and output voltage reach to 5V.

(3) Add LDO unit one by one. Work correctly until 11 units connection. When connecting 12 unit, input voltage fall to 3V and all of units don't work.

* I checked the power supply, but there is no probrem without current limit.

Can you please advise me why unstable behavior happen? Is there any protection work? Is there any solution to solve this phenomenon?

Thanks in advance.

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SN65HVDA100-Q1 Question about dominant output

HIDE — Tue, 18 Jun 2013 09:28:24 GMT

Hi,

I have a question about dominant output on SN65HVDA100-Q1.

Step1. Enable turn from Low to High.

Step2. After passing 20usec from Step1, TXD turn from Low to High.

As the result, after turning Enable to High, I confirmed dominant output for 20usec. The dominant output seems input data between above 1 and 2.

Could you please advice me to avoid the dominant output?

Thanks in advance.

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The ultrasonic sensor for PGA450-Q1

Atsushi — Mon, 17 Jun 2013 09:16:51 GMT

I have a question of the ultrasonic sensor for PGA450-Q1.

We can use the frequency range 40kHz to 70kHz for Digital path.

So, usually, the frequency of the ultrasonic sensor should be 40kHz to 70kHz.

Is it correnct?

And I wolud like to confirm how much can PGA450-Q1 drive the frequency of the ultrasonic sensor

even if PGA450-Q1 can not receive the signal.

Best regards,

Atsushi Yamauchi

TL720M05-Q1 Output current limit specification

Atsushi — Wed, 12 Jun 2013 08:55:59 GMT

I would like to confirm the variation of output current limit of TL720M05-Q1.

I think the variation depends on the temperature and the initial variation itself.

But I don't understand the big vatiation (450mA to 950mA), because the temperature characteristics of the current limt is flat in the datasheet.

Could you please teach the cause of the vatiation?

Best regards,

Atsushi Yamauchi

TPS7A6550-Q1 output capacitor

Atsushi — Fri, 30 Nov 2012 15:15:57 GMT

I have a quetion of output capacitor value for TPS7A6550-Q1.

There are not any specifications of the value for output capacitor in the datasheet.
And the customer wants to use 330uF and low ESR capacitor.

Are there any problems of using 330uF capacitor?

And in the case of TL720M05-Q1, the value of the capacitor is C > 22uF and ESR < 5 ohms in the
datasheet. What is the value for TPS7A6550-Q1?

Best regards,
Atsushi Yamauchi

TPS7A66xx-Q1　Output Capacitor

Atsushi — Mon, 17 Jun 2013 04:59:44 GMT

I would like to confirm the output capacitor for TPS7A66xx-Q1.

The customer wants to use the electrolytic capacitor 330uF with the ceramic capacitor 0.1uF in parallel.

Are there any problem by the capacitors?

I think it will be stable because TPS7A66xx-Q1 has the stable region by the ESR and the capacitor (bigger than TPS7A65xx/63xx-Q1).

If possible, could you please teach the required ESR (with the capacitance).

Best regards,

Atsushi Yamauchi

SN65HVDA100-Q1 Question about delay time

HIDE — Fri, 07 Jun 2013 07:29:42 GMT

Hi,

I have two questions about SN65HVDA100-Q1.

Q1. Is there any delay time between enable transitions high and mode transitions normal? (I'd like to know the delay time from EN=HIGH to turning on normal mode.)

Q2. On the normal mode, is there any delay time between TXD input and LIN output? (I'd like to know the data transmission delay from TXD to LIN.)

Thanks in advance.

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TPS62065QDSGRQ1

Kento Harada — Fri, 31 May 2013 09:30:17 GMT

Hello,

As for TPS62065QDSGRQ1, my customer ququires dimention drawing of Exposed thermal PAD and recommendation land pattern.

Please give me the these documents

Help on PGA400 Offset Correction

Tushar Kulkarni — Fri, 17 May 2013 04:04:42 GMT

Hi,

In PGA400 I need to set Offset ZTC Compensation and Offset PTAT Compensation at sensor calibration time,

will it possible to put offset value in Register Bank and write to ZTC and PTAT register?

Logic I am thinking is, if I have resistive sensor then it may possible that it will have different offset at ambient temperature, I will set ZTC and PTAT Offset such as I will neutralize ADC count. For that I will put Hex value to Bank_0 REG 00 and 01 and PGA400 will put that value to ZTC and PTAT.

Will it possible?

Tushar

The solutions against battery reverse connection and minus surge for UCC27201-Q1

Atsushi — Thu, 23 May 2013 15:43:49 GMT

I have questions for UCC27201-Q1

Could you please advise them to me?

Q1. In this case, 12V adds on VH through HI, LI, and VSS. Are there any problem?

Q2. If there are any problem, could you please teach the provision for this case?

Q3. In the case of this condition (there is minus surge at +Vcc(12V)), can UCC27201-Q1
endure the surge level (voltage, time and so on) in this case?

Q4. If there are any problem, could you please teach the provision for minus surge?

Q5. Are there any problem in this circuit against minus surge (add resisitors and diode)?

Q6. Are there any problem in this circuit against minus surge (add resisitors and diode, R1 gets
through the power of the surge and D1 protects UCC27201 against the surge )? Best regards,

Atsushi Yamauchi

TPIC6C596 cascade operation

Atsushi — Tue, 28 May 2013 09:17:52 GMT

I would like to confirm the cascade operation of TPIC6C596.

How many the cascade connection of TPIC6C596 can we use?
The demand is 7 or 8 cascade connections if we can.

Best regards,
Atsushi Yamauchi

ISR Corruption Issue

Jeremy Brookley — Wed, 24 Apr 2013 23:04:12 GMT

Hello, Clancy.

We were having a problem with I2C (though realistically, it probably affects the whole commBuff ISR, regardless of whether it's I2C or SPI). What we've narrowed it down to is a switch statement in the ISR.

We are sending 8 commands per second via I2C and after a while (it ranges from a few minutes to half an hour), the chip appears to lockup. However, on closer inspection, the chip itself is still running. However, it appears that some variables in the ADC ISR are being corrupted/changed, causing our CalcDAC routine to fail to run anymore. The basic code looks like this:

void commBuff_ISR (void) interrupt 6    using 3
{
        unsigned char commData;

EA = 0;    /* Added 04-23-13 */

        commData = COMBUF; /* Read Data from COMBUF */

        if((CommandState!=7)&&(CommandState!=8)&&(CommandState!=10)&&(CommandState!=11)&&(commData==0x24))
        {
                        CommandState = 0;
        }


        switch (CommandState)
        {
                case (0):
                        if (commData == 0x24) /* 0x24 = '$' */
                        {
                                CommandState +=1;
                        }

                        else if (commData == 0x62)      /* 0x62 = 'b' */
                        {
                                COMBUF = DigOut;
                        }
                        break;
                default:
                        break;
        }
EA = 1;    /* Added 04-23-13 */
}

This is just to display the functionality of the code (not the entirety of the code.  We actually have 14 additional switch cases that are not shown here).  What I found is that the switch statement seems to be causing some kind of issue that is causing corruption in the ADC ISR.  If I change the switch statement to an if statement instead, it seems to fix the issue.

I posted about this in the keil forums (under the name of John Dough. I've had issues with the people in that forum in the past.  At this point, I don't give them my name there anymore):

http://www.keil.com/forum/22943/

 They seem to suggest it's related to the PGA400 itself rather than Keil (personally, I have a hard time believing that but I thought I would talk to you about it).  Do you know anything about this or why it would cause issues between the ISRs?

Any help you can give me would be appreciated.  Thanks!

-Jeremy

TPS65381 - Watchdog related issue

mohamed mohideen — Thu, 16 May 2013 09:50:52 GMT

Hi,

Iam using TPS65381 in our application, Through SPI , Im trying to configure the registers of TPS65381(In diagnostic mode) based on our application needs But before that itself , It is going to safe mode. (Im using Watchdog Q&A mode and the controller is TC274)

The very first data i sent to TPS65381 is for holding the regulator in diagnostic mode( DIAG_EXIT_MASK = 1) with associated command

Could you please provide the solution to configure the register before it going to SAFE state.

TPIC8101 Integrator Details

Garrett Anderson — Wed, 22 May 2013 18:32:41 GMT

I am in process of developing a control system for a dual fuel engine that runs on diesel and natural gas. I am using a knock detection system that is based on the TPIC8101 and am having some trouble calibrating the system. In an effort to reduce the time that I need the test cell and better understand how the system functions, I am trying to construct a simple Simulink Model to allow me to utilize some high speed data that I collected directly from the knock sensors.

To verify my model I am trying to reproduce the simple example in the training pdf that I found here in the forum which I have attached. I have not been able to do this, but I think that I do not fully understand how the integrator works. The transfer function listed in the spec sheet mentions that you use the peak voltage of the knock signal. Is this implying that the integrator has some sort of peak detection? Are there details that are left out of the spec sheet that are implied?

Any information that you could provide me would be appreciated. I hope that I am just missing something simple.

Thanks,

Garrett

TPS65381-Q1 Transients

Rustin Schroeder — Tue, 21 May 2013 19:58:11 GMT

In our application for the TPS65381-Q1, we will have various transients (ISO7637 pulses) on the battery line. I see in the datasheet that the TPS65381-Q1 is rated at a maximum voltage of 40V; however, is it able to handle transients above that?

UCC28950

Omid Mostaghimi — Fri, 15 Mar 2013 17:55:59 GMT

I am using a UCC28950 phase shift controller in a bridge 700W dc-dc converter. at no load I get the output regulated voltage but as soon I start loading the circuit up the output drops quickly. As I am failry confident that the compnesation is right, I looked at the current sense voltage to make sure we are not in cycle by cycle current protection mode. From the voltage graph I see the voltage exceeds 2V and the controller turns off for a short time and the cycle repeats. Can you please advise me on this? on how to get around this or what can cause this? Bearing in mind in a slightly lower power version of this converter there is no problem in loading the converter at all (the inout voltage range, output regulated voltage and switching frequency are exactly the same).

the setting of FET ON constantly for UCC27201-Q1

Atsushi — Wed, 15 May 2013 02:53:08 GMT

I would like to confirm how to set FET ON constantly with UCC27201-Q1.

The customer came up with adding the high voltage on VHB by charge pump circuit instead of bootstrap capacitor.

But I think it is not recommended for this device.

Could you please teach the idea for how to set FET ON constantly?

(Please visit the site to view this file)

Best regards,

Atsushi Yamauchi

TL720M05-Q1 stability for output capacitor

Atsushi — Thu, 16 May 2013 00:47:25 GMT

For the stable operation for TL720M05-Q1, Cout is >22uF and ESR <5 ohm.

If you have, could you please the data of the stability by the capacitance and ESR (like the figure of TPS7A65xx-Q1)?

Best regards,

Atsushi Yamauchi

How to stop TPS65381 resetting function?

Jiaming Sun — Sun, 12 May 2013 09:26:54 GMT

hi,all

I want to use TPS65381 as powersupply and watchdog for TMS570LS3137,but the question is when I download program to TMS570LS3137 with JTAG, on this occasion，TMS570 can't feed the watchdog inside TPS65381,then TPS65381 is going to reset TMS570.If it is so ,how can I solve this problem ?

Hope to reply soon.Thanks a lot.

TPS7A6550-Q1 PSpice Model

Atsushi — Fri, 26 Apr 2013 01:35:02 GMT

The customer want to use TPS7A6550-Q1 Spice simulation.

I have found there is TPS7A6533-Q1 model, but there is not TPS7A6550-Q1 model.

Could you please provide TPS7A6550-Q1 PSpice mode if you can?

Or can we use TPS7A6533-Q1 model for TPS7A6550-Q1 simulation with aranging TPS7A6533-Q1 moel?

Best regards,

Atsushi Yamauchi

TPS65381 - Standby Mode Current Consumption

Rustin Schroeder — Fri, 26 Apr 2013 13:49:57 GMT

Does TI have any additional data regarding current consumption in standby mode? For example, data across the full operating voltage range and across temperature would be helpful to understand maximum current consumption.

Clip from page 4 of 2p92 datasheet.

transformer part # in PGA450 EVM

Jimmy Ng — Thu, 07 Feb 2013 05:59:04 GMT

Someone please tell me what is the Toko part # for the transformer used in PGA450-Q1 Evaluation Module. I can only see A519 I49J in the body marking but I cannot find it in Toko website.

Please advise.

Regards,

Jimmy Ng

TPS65381-Q1 VDD6 Supply Output Caps

Rustin Schroeder — Mon, 06 May 2013 20:49:21 GMT

For the VDD6 supply output capacitors, I have two questions:

1) Is the ESR critical? Many ceramics are going to be less than 100mohm.

2) Is the output capacitance range considered to be nominal capacitance or worst-case with tolerance, temperature, and DC bias effects?

The stability with Cout ESR for TPS7A6350-Q1

Atsushi — Fri, 26 Apr 2013 09:34:03 GMT

Hello,

Do you have the stability data with ESR of TPS7A6350-Q1 like the data of TPS7A65xx-Q1?

The customer wants the data of TPS7A6350-Q1, because they use electrolytic capacitor.

Best regatds,

Atsushi Yamauchi

TPS65381 - thermal pad size

Rustin Schroeder — Fri, 26 Apr 2013 04:45:30 GMT

Both the mechanical data in the datasheet and the separate package drawing for TI # TPS65381 shows the dimensional data of the part but then states that the thermal pad size and shape is shown on a separate sheet. This separate sheet does not exist in either document. Could you please point me to where the thermal pad dimensions are for this part? Thank you.

Automotive Forum - Recent Threads

TL720M05-Q1 Question about Input Voltage Drop

SN65HVDA100-Q1 Question about dominant output

The ultrasonic sensor for PGA450-Q1

TL720M05-Q1 Output current limit specification

TPS7A6550-Q1 output capacitor

TPS7A66xx-Q1 Output Capacitor

SN65HVDA100-Q1 Question about delay time

TPS62065QDSGRQ1

Help on PGA400 Offset Correction

The solutions against battery reverse connection and minus surge for UCC27201-Q1

TPIC6C596 cascade operation

ISR Corruption Issue

TPS65381 - Watchdog related issue

TPIC8101 Integrator Details

TPS65381-Q1 Transients

UCC28950

the setting of FET ON constantly for UCC27201-Q1

TL720M05-Q1 stability for output capacitor

How to stop TPS65381 resetting function?

TPS7A6550-Q1 PSpice Model

TPS65381 - Standby Mode Current Consumption

transformer part # in PGA450 EVM

TPS65381-Q1 VDD6 Supply Output Caps

The stability with Cout ESR for TPS7A6350-Q1

TPS65381 - thermal pad size

TPS7A66xx-Q1　Output Capacitor