TPS92630-Q1: Query about Number of LEDs per channel

Hi Kanthavel,

Sorry, this setting will lead to the device's temperature over 200℃, which is far over the Operating ambient temperature of this device.  So it's not OK.

If you have such a need to light 5 LEDS like this, I recommend TPS92633-Q1(Three-Channel Automotive High-Side LED Driver with Thermal Sharing
and Off-Board Binning). I believe it will help you complete this setting.

Best regards,

Gracie

Hello Gracie,

Thank you for your valuable reply. Kindly provide TPS92633-Q1 maximum current capacity for our combination. 

5 LEDs + 1 Zener diode for LED replacement  like OUT1 - 2 LEDs, OUT2 - 2 LEDs and OUT3 - 1 LED + 3V, 1W Zener diode

Hello Gracie,

Also please provide current handling capacity at TPS92630-Q1 2 device parallel combination. Please reply quick, Need to respond to customer by this week end.

For our reference i am listing queries here

1. TPS92630-Q1 maximum current capacity

2. TPS92633-Q1 maximum current capacity

3. TPS92630-Q1 maximum current capacity 2 device parallel combination

Hi Kanthavel，

For your information, the overheating problem in the TPS92630 problem lies in the voltage too high not the current.

In fact, TPS92633 has an output full current loads up to 150 mA per channel with large voltage variations. So the working temperature is decided by the voltage. The external shunt resistor is for Thermal sharing. However, TPS92630 does not have such design. That results in the thermal difference.

Best regards,

Gracie

Hello Gracie,

Thanks for your reply.

Our customer selected TPS92630 part based on below key features. If i need to switch the part, i need to show the Design/Application constrains of TPS92630.

As TPS92630 Datasheet,

1. The operating voltage range will be 5 V–40 V. We are only having 9-16V(Worst case 18V) operating range. 

2. Operating current per channel 150 mA. We are only having 100 - 130 mA. 

3. Also OUT1, OUT2, OUT3 we have typically 6V ( 2 LEDs in series with VF = 3V).

So please explain what are all the deviations/constrains which leads part change. Also provide operating limit like (Current value) for the above.

Also please share Case studies and Errata for below applications

Page number 24, "Stoplight and Taillight Application With PWM Generator" without tail input

Page number 28, "Two TPS92630-Q1 Devices in Parallel for Large Loads"

Hello Gracie,

Also please consider my additional queries as per below:

1. Before move to TPS92633 part may i try TPS92630 parallel combination as per application note at Page number 28, "Two TPS92630-Q1 Devices in Parallel for Large Loads".

2. What would be the behavior (LED off or LED intensity reduction) if the input voltage is between 6V to 9V or input voltage will be lesser than the device Vdrop voltage + (N*LED Typical forward voltage drop).

3. If LED off will be result of above case, then Is it possible to overcome the switch off condition in the above case.

4. We have Temperature compensation requirement. Tth will be 70 deg. To achieve this as per below image, 30K pull up to 3.3V reference introduced by using Zener diode and series Zener resistor combination. Please check whether it is ok or please suggest simple LDO part. (both 5V & 3V3 part is ok for us). As of ambient 70 deg only considered. Thermal simulation need to be done. As of now please consider board thermal rise as +15 deg.

5. Also please share Case studies and Errata of TPS92630 & TPS92633 for our application.

Hello Gracie,

Please respond quickly. This design our customer planning for preproduction. Hence please share case studies and Errata for above components TPS92630 & TPS92633. Need immediate update on our requirement vs part constraints. Please consider this as high priority. 

Thanks,

Hi Kanthavel,

I'm working to calculate and show you the results. Please give  me a little more time.

BR, Gracie

Hi Kanthavel,

I had a really busy day and am sorry about replying late. In your condition, consider Vin=18V, and each channel has a maximum voltage as 6V, then the device will get 130mA*3*12V=4.68w.According to the thermal information from datasheet, this device will get to 194.22 deg. Plus the environment temperature, this device will certainly be over 200 deg.

About the datasheet, I don't think there is an errata. Could you please specify in another new thread?

Hello Gracie,

We are looking on your feedback. Please answer our below alternate plan queries.

1. Before move to TPS92633 part may i try TPS92630 parallel combination as per application note at Page number 28, "Two TPS92630-Q1 Devices in Parallel for Large Loads".

2. What would be the behavior (LED off or LED intensity reduction) if the input voltage is between 6V to 9V or input voltage will be lesser than the device Vdrop voltage + (N*LED Typical forward voltage drop).

3. If LED off will be result of above case, then Is it possible to overcome the switch off condition in the above case.

4. We have Temperature compensation requirement. Tth will be 70 deg. To achieve this as per below image, 30K pull up to 3.3V reference introduced by using Zener diode and series Zener resistor combination. Please check whether it is ok or please suggest simple LDO part. (both 5V & 3V3 part is ok for us). As of ambient 70 deg only considered. Thermal simulation need to be done. As of now please consider board thermal rise as +15 deg.

5. Also please share Case studies of TPS92630 & TPS92633 for our application.

Thanks,

Kanthavel Kumaran