OMAP-L137
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SPRS563G – SEPTEMBER 2008 – REVISED JUNE 2014
6.2
Recommended Clock and Control Signal Transition Behavior
All clocks and control signals
must
transition between V
IH
and V
IL
(or between V
IL
and V
IH
) in a monotonic
manner.
6.3
Power Supplies
6.3.1
Power-on Sequence
The device should be powered-on in the following order:
1. RTC (RTC_CVDD) may be powered from an external device (such as a battery) prior to all other
supplies being applied or powered-up at the same time as CVDD. If the RTC is not used, RTC_CVDD
should be connected to CVDD. RTC_CVDD should not be left unpowered while CVDD is powered.
2. Core logic supplies:
(a) CVDD core logic and RVDD supply
(b) Other 1.2V logic supplies (PLL0_VDDA).
Groups 2a) and 2b) may be powered up together or 2a) first followed by 2b).
3. All 1.8V IO supplies (USB0_VDDA18, USB1_VDDA18).
4. All digital IO and analog 3.3V PHY supplies (DVDD, USB0_VDDA33, USB1_VDDA33).
If
both
USB0 and USB1 are not used, USB0_VDDA33 and USB1_VDDA33 are not required and may
be left unconnected.
Group 3) and group 4) may be powered on in either order [3 then 4, or 4 then 3] but group 4) must be
powered-on after the core logic supplies.
There is no specific required voltage ramp rate for any of the supplies.
RESET must be maintained active until all power supplies have reached their nominal values.
6.3.2
Power-off Sequence
The power supplies can be powered-off in any order as long as the 3.3V supplies do not remain powered
with the other supplies unpowered.
Copyright © 2008–2014, Texas Instruments Incorporated
Peripheral Information and Electrical Specifications
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