TMS320F28335_1 Datasheet, PDF (111/166 Pages) Texas Instruments – Digital Signal Controllers (DSCs)

TMS320F28335, TMS320F28334, TMS320F28332
www.ti.com
Digital Signal Controllers (DSCs)
SPRS439B – JUNE 2007 – REVISED OCTOBER 2007
6.4.1 Reducing Current Consumption
Like 280x and 281x, F2833x DSPs incorporate a unique method to reduce the device current
consumption. Since each peripheral unit has an individual clock-enable bit, significant reduction in current
consumption can be achieved by turning off the clock to any peripheral module that is not used in a given
application. Furthermore, any one of the three low-power modes could be taken advantage of to reduce
the current consumption even further. Table 6-4 indicates the typical reduction in current consumption
achieved by turning off the clocks.
Table 6-4. Typical Current Consumption by Various
Peripherals (at 150 MHz)⁽¹⁾
PERIPHERAL
MODULE
ADC
I2C
eQEP
ePWM
eCAP
SCI
SPI
eCAN
McBSP
CPU - Timer
XINTF
DMA
FPU
I_DD CURRENT
REDUCTION (mA)
8 ⁽²⁾
2.5
5
5
2
5
4
8
7
2
10 ⁽³⁾
10
15
(1) All peripheral clocks are disabled upon reset. Writing to/reading
from peripheral registers is possible only after the peripheral clocks
are turned on.
(2) This number represents the current drawn by the digital portion of
the ADC module. Turning off the clock to the ADC module results in
the elimination of the current drawn by the analog portion of the
ADC (I_DDA18) as well.
(3) Operating the XINTF bus has a significant effect on IDDIO current.
It will increase considerably based on the following:
• How many address/data pins toggle from one cycle to another
• How fast they toggle
• Whether 16-bit or 32-bit interface is used and
• The load on these pins.
NOTE
I_DDIO current consumption is reduced by 15 mA (typical) when XCLKOUT is turned off.
NOTE
The baseline I_DD current (current when the core is executing a dummy loop with no
peripherals enabled) is 165 mA, typical. To arrive at the I_DD current for a given application,
the current-drawn by the peripherals (enabled by that application) must be added to the
baseline I_DD current.
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Electrical Specifications 111