Integrating the LPC54102 and MC33908 for Safety Applications

[lpcware]

Content originally posted in LPCWare by jhd on Wed Dec 23 11:06:51 MST 2015
Hello,

I'm connecting (trying it  :) ) a MC33908N and LPC54102 and I have some doubts, to see if you can help me.

I followed the AN4442 (Rev.2, 2014)  Integrating the MPC5643L and MC33908 for Safety Applications and AN5099 (rev.0,4/2015). I have not found a AN to integrate the LPC54102 but I guess that is similar to MPC5643L.

I need to power a LPC54102 and other periphericals with 3,3V from a 12V battery (normally Yuasa, 12V (16A, 18A, 20A) similar to this for Yamaha VX 2009-2012 http://www.yuasa.co.uk/ytx20hl-bs-pw.html). 

The circuit is to be powered generally by Yamaha VX/VX110 and/or BRP SeaDoo GTI 130 (of any year). And it is connected to Accesories Bus from the PWC. This bus has a mini auto fuse of 15A (LittlelFuse).

Supplying power devices are as follows:

LPC54102  -- 3V3 - I think as much 10mA.
BMX055  --  About 5.5mA
BMP280  --  2.7uA
Telit SL869 GPS --  3V3  Acquisition GPS+GLO = 67 mA
Adeunis NB868-500mW  --  3V3  -- Tx=700mA(27dbm) :: Rx=35mA

I believe that I can connect to VCore (3.3V) of MC33908 the LPC54102, BMX055, BMP280 and Telit SL869 GPS, but the NB868-500mW It consumes 700 mA when transmitting, and I think the VCore the MC33908 can only deliver up to 300mA (please correct me if I'm wrong). If so, then where I can connect the NB868-500mW?

I attach a portion of the schematic in pdf because I'm having problems when exporting to pdf in KDE with Kicad.  Anyway you can see it from Kicad ,  https://github.com/jetremote/JetRemoteXP

Sorry me english.

Best regards

[lpcware]

Content originally posted in LPCWare by jhd on Mon Dec 28 09:42:34 MST 2015
Hello,

I chose this model, BUK9Y07-30B

Do you think that circuit works to deliver to the load +12V?

Regards

[lpcware]

Content originally posted in LPCWare by jhd on Fri Dec 25 14:54:21 MST 2015
Something like PMCPB5530X but whose ID (drain current) is between 10A and 15A and the IDM (peak drain current) greater than 30A.

[lpcware]

Content originally posted in LPCWare by jhd on Fri Dec 25 14:04:24 MST 2015
Yes, you're right. Thank you. I was confused with Vgs (th), which was active between 2.4V and 4V but only 1mA drive current.  http://electronics.stackexchange.com/a/157085

Anyway, I think I've also wrong in choosing the MOSFET, I think one must be N channel and another P channel.

I want to use only one signal (one gpio from LPC54102) to activate the two MOSFET. (they will only use one, but in this way the same circuit used for both brands).

Yamaha Waverunner engines are turned off by applying GND to one cable. BRP Seadoo engines (130 GTI and SPARK) go off applying +12V to a cable. (While applying + 12V engine will shutdown, and it is impossible to start it while it is being applied, so it does the Yamaha but applying GND).

I measured the circuits start / stop of both brands and the voltage is 12V and amperage when starting the engine is between 1.2A and 1.8A (with a DC clamp meter CMP-401 Sonel.

Regards

[lpcware]

Content originally posted in LPCWare by wmues on Fri Dec 25 04:07:57 MST 2015
Have you checked that this Mosfet needs 4.5Volt as gate-source voltage (worst case).

[lpcware]

Content originally posted in LPCWare by jhd on Thu Dec 24 07:28:22 MST 2015
Thanks Wolfgang.

Yes, I has choosed MC33908NAE (1 CAN, 0 LIN) Vcore 1.5A

I was confused, then the data of Figure 58 refers to MC33907x.

Then I'll use Vcore for all except to MOSFET, for the MOSFET I'll use VCCA, and Vaux not used as in Figure 61.

For this MOSFET  http://www.nxp.com/documents/data_sheet/BUK7K5R1-30E.pdf

To be controlled from the LPC54102 (pin 4 as gpio) with an optocoupler.  Do you think it is viable as well?


Merry Christmas!

[lpcware]

Content originally posted in LPCWare by wmues on Thu Dec 24 05:51:37 MST 2015
The MC33908 has a Vcore current of 1.5A.
The MC33907 has a Vcore current of 0.8A.

If you use the MC33908, where is the problem?

http://cache.nxp.com/files/analog/doc/data_sheet/MC33907-MC33908D2.pdf
Page 3

Regards
Wolfgang

[lpcware]

Content originally posted in LPCWare by jhd on Thu Dec 24 03:38:06 MST 2015
Thanks wmue,

I was wrong, Vcore has a current range 10mA -> 800mA, DI/DT = 2A/uS   (as Figure 58 in datasheet).

But, What does it means DI/DT = 2A/uS ?

If Vcore supports 800mA then I can connect the RF module (700mA TX) plus GPS receiver (67mA in acquisition) plus LPC54102, BMP280 and BMX055.

You think you can be too much or right? I do not need to connect anything else, just one 2-channel MOSFET to act as solid state relay. (DPST - Double pole, single throw).

Regards

[lpcware]

Content originally posted in LPCWare by wmues on Wed Dec 23 11:58:33 MST 2015
For 3,3V, you only need the PRE regulator of the MC33908N.
The PRE regulator can deliver 2,0A.

Where is the problem? Have you read the data sheet?