Hi,
I want to run my omapl138 board at 456MHz, but the core voltage is 1.3V , is there a PMIC to be suggested? I checked the power supply reference designs from the Analog eLAB,but all of them focus on core voltage 1.2V.
Thanks!
This question is better phrased as the following.
Since the power supply reference design (as linked above) runs the core voltage a 1.2V, is there any way to scale the PMIC at 1.3V?
-Drew
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Are you aware of the TI Processors Wiki? This is a good place to search for additional support on TI ARM+DSP Application Processors.
For the TPS63070 (as used in Powering Freon with TPS65070, slva371a) , using the I2C bus you can program the DCDC3 output to 1.3V by changing either register DEFDCDC3_HIGH/LOW [5:0] = 0 1 0 1 1 1 or by setting DEFDCDC3_HIGH[7] = 1 and connecting an external resistor divider to the output of the converter. Please note, the I2C register write needs to happen each time Vin of the TPS65070 goes below UVLO or PB_IN is held low for 15s as described on page 40 of the TPS65070 datasheet:
Daniel,
Thanks for your reply; I will use TPS65023 to solve the problem, The TPS65023 DCDC1 can output a range of 0.6V to VINDCDCx by connect a resistor divider between VDCDCx and GND. I check omapl138 datasheet ,only core voltage suppply must be 1.3V at 456MHz, other devices on chip just 1.2V , so I must think about the
1.2V power supply. Can I connect the 1.2V power supply devices to 1.3V directly? The datasheet tell me that the 1.2V device maxim voltage can up to 1.32V , So I am afraid that the 1.3V ouput exceed 1.32V.
That might be more of a question for the OMAP team. Can the rails that are typically 1.2V (RVDD, PLL0_VDDA, PLL1_VDDA, SATA_VDD, USB_CVDD, USB0_VDDA12 and RTC_CVDD) handle the 1.3V core voltage? Drew can you comment?
One solution would be to use something like TPS72012 connected to the 1.3V rail and biased from TPS65023 VIN.This would provide you 1.3V for your core and 1.2V for the other rails (RVDD, PLL0_VDDA, PLL1_VDDA, SATA_VDD, USB_CVDD, USB0_VDDA12 and RTC_CVDD).
ben zhan 1.2V power supply. Can I connect the 1.2V power supply devices to 1.3V directly? The datasheet tell me that the 1.2V device maxim voltage can up to 1.32V , So I am afraid that the 1.3V ouput exceed 1.32V.
OMAP-L1x devices can handle both 1.2 & 1.3 volts on the Core VDD (CVDD) depending on the speed grade.. You would use a nominal 1.3V for 456 MHz clock speed, and a nominal 1.2V for 375MHz clock speed.
I think Ben was referring to RVDD, PLL0_VDDA, PLL1_VDDA, SATA_VDD, USB_CVDD, USB0_VDDA12 and RTC_CVDD at 1.3V as well.
Thanks, Yes, I was referring to RVDD,PLL0_VDDA,PLL1_VDDA,SATA_VDD,USB_CVDD,USB0_VDDA12 and RTC_CVDD at 1.3V .
Daniel AcevedoI think Ben was referring to RVDD, PLL0_VDDA, PLL1_VDDA, SATA_VDD, USB_CVDD, USB0_VDDA12 and RTC_CVDD at 1.3V as well.
Hi Daniel -
Yep - I missed this - Thanks for calling me out :)
1.2V is nominal for these supplies - however 1.3V is within the recommended operating conditions of [1.14 - 1.32] as specified in the OMAP-L138 Electrical Characteristics of the datasheet.
Hi Drew,
Thanks for your reply. I know that OMAP-L1x devices can handle both 1.2 & 1.3 volts on the Core VDD (CVDD) depending on the speed grade。But when I used 1.3V CVDD, but RVDD, PLL0_VDDA, PLL1_VDDA, SATA_VDD, USB_CVDD, USB0_VDDA12 and RTC_CVDD must be 1.2V ,Right?. As you said and discribed in datasheet ,
I can use 1.3 to supply for 1.2V voltage power.
Another question : I can't find out something about the power consume in omapl138 datasheet SPRS586C.
ben zhan,
Please refer to section 4.2 in the OMAP-L138 Datasheet.
ben zhanAnother question : I can't find out something about the power consume in omapl138 datasheet SPRS586C.
Power Consumption is a factor of Core Frequency, Peripherals Used, and CPU Load. We have created a spreadsheet to help you estimate the power consumption in the OMAP-L138 based upon your desired peripheral selection