DM385 and DM388 Power Consumption Resources

DM385 and DM388 Power Consumption Resources

Introduction

This page discusses the power estimation based on DM385, DM388 power domains, and operating modes..
There are power supplies that are fixed and adjusted for the OPP mode. See Datasheet section 6.2.

Fixed Supplies

SupplyName	Device pins	voltage
DVVD	IO Standard pins	3.3v, 1.8v
DVVD_GPMC	GPMC pins	3.3v, 1.8v
DVVD_RGMII	RGMII pins	3.3v, 1.8v
DVVD_SD	SD pins	3.3v, 1.8v
DVVD_C	C pins	3.3v, 1.8v
DVVD_DDR	DDR pins	DDR2-1.8v, DDR3-1.5v, DDR3L-1.35v
VDDA_USB	analog USB	3.3v (doesn't include 5v sensing)
VDDA_1p8	analog PLL	1.8v may require ferrite filtering
VDDA_HDDAC	analog HD-DAC	1.1v
VREFSSTL	DDR IO Reference	.5*selected DDR voltage

Variable power supplies based on OPP mode

Power Supply	Type	OPP_100	OPP_120	OPP_Turbo	OPP_Nitro
CVVD	Logic core	1.1	1.2	1.35	1.35
CVVD_ARM	ARM core	1.1	1.2	1.35	1.35
CVVD_HDVICP	HDVICP core	1.1	1.2	1.35	1.35

Note: there is no AVS, or Dynamic scaling of these power varied power supplies.

The operating mode of the DM38x, determines both the speed of the processors and accelerators, and the voltage. in the Thermal Consideration Report (see References)

OPP100	OPP120	OPP_Turbo	OPP_Nitro
~1.2w	~1.5w	~2.9w	~3.8w

The IPNC Reference, discusses power sources of Power-Over-Ethernet (POE), 5v external.

The DM38x Power can be estimated from the DM385_PowerSpreadsheet_Ver1.00 Excel Spreadsheet. The items in white, upper right select the OPP mode. Depending on the usage, you may be able to change one of the core voltages based on the needed Mhz for the core, ARM, or hardware accelerators; L-N33. Further customization can be done in the white areas C40 to I461 of the Power Estimation tab, following the DM38x datasheet and technical reference manuals. Note: V33 has the DDR2/DDR3/DDR3L voltage. The v1.00 Excel spreadsheet can be downloaded here File:DM385 PowerSpreadSheet Ver1 00 Release.zip

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Once you have completed the power estimation, and have your engineering margin, the power supply subsystem can be designed. There are both PMIC and discrete solutions. Some of the PMIC solutions have logic enables, so you can take advantage of power sequencing. The power sequencing is described in the datasheet, and Hardware Resources wiki page.

References

DM385/388 Datasheet - [1]
DM38x Technical Reference Manual - [2]
IPNC Net Camera Reference, discussing DM385 Power - [3]
DM36x, DM38x Thermal Consideration Report (dnload) - [4]