Power to NPU
In the KL720 demo board, why have you used dedicated step down regulator (MP1614C), instead of using BUCK1 of MP5424 which is not used and set by default to the same power?
If it's to enable when needed, can't it be controlled with I2C signals of MP5424?
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Comments
KL720 has cpu/npu inside , MP1614C provided NPU power (0V9_NPU) MP5424 for CPU power (0V9_BAS / 1V2BAS / 1V8_BAS / 3V3_BAS), NPU power will controled by "X_PSW_NPU" pin
If used I2C to control MP5424, two items need to consider
Thanks,
Can you explain the power system?
I didn't understand how the KL720 is power by the PMIC's (MP5424 and MP1614) and it also provide the PMIC's enable signals (" X_PSW_BAS" and "X_PSW_NPU").
Please note that my design will be powered by battery (not USB), if you have any recommendation on that I will be happy to hear.
Moti.
Hi Moti,
In KL720, we have couple of power domains shown in below picture:
Each power domain has its controlled signal named : PSW_XXX
For example, base domain is controlled by PSW_BAS
in our design, we simply use PSW_BAS and PSW_NPU to control/separate KL720's power.
PSW_BAS is controlled by KL720's hardware. it will automatically turn high after KL720 is booted successfully.
PSW_NPU is controlled by KL720' FW. Firmware can decide weather they want to turn on NPU's power to do some inferencing or shut it down to save some power.
Thanks..
"Power on sequence of MP5424 must early then KL720"
"PSW_BAS is controlled by KL720's hardware"
If PSW_BUS enables MP5424, I don't understand how MP5424 powers early them KL720?
Can you recommend how to Power the system from battery only (no USB power in the system)?
Moti.
Hi Moti,
"Power on sequence of MP5424 must early then KL720"-> means that if you want to use i2c to control MP5424, there should be a "Host" to control MP5424 via I2C. Then MP5424 supply the power for KL720
The power I suggest may like following:
Thanks.
But on the schematic I can see that VCC09V_OSC12M and VCC18IO_RTC are also generated by MP5424.
How is it always on? isn't it also enabled by X_PSW_BAS?
Hi Moti,
MP5424 has 4 buck and 3 LDOs.
LDO is not control by EN1, its controlled by Vin.
Are you going to use MP5424 as well?
if so, please contact MPS sales person:
//////////////////////////////////////////////////
Ava Chen
MPS International (Taiwan) Ltd.
DCDC PL Business Development
Tel +886-2-86911648
mobile +886-911185454
Ava.Chen@monolithicpower.com
29F, No. 97, Sec.1, Xintai 5th Rd., Xizhi Dist.,
New Taipei City 22175, Taiwan
/////////////////////////////////////////////////////////
They created a specific part number for KL720 called MP5424-0010.
This one can fullfill KL720's power on sequence and voltage requirement.
You can also ask datasheet for your reference.
BTW, I can help you to review your schematic if you want.
Just give me a email.
Thanks.
Thanks Warren,
We will use MP5424, already contacted MPS (in our region) and received data sheet and the OTP settings.
Will be happy to send you the schematic for review.
My email : moti@tapwithus.com, please send me an email and I will reply
Thanks for the support.
Moti.