Other Parts Discussed in Thread: OMAP-L137
Hi,
In this post, i specified the part no as OMAP-L138, but that is actually OMAP-L137 to navigate the correct forum.
Here is my customer`s power supply sequence.
OMAP L137 Data sheet says like :
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.
Because the datasheet does not specify the threshold for valid voltage on each power line, the customer`s power supply sequence seems ok for me. Could you please double check ?
Ideally, the following should be preferred, but the data sheet does not say so clearly.
Best Regards,
NK
