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Andrew_G
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Joined: 18/10/2016
Location: Australia
Posts: 871

Posted: 12:51am 03 Nov 2019

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Hi,
I am assembling my new MMBackPack V3 from Silicon Chip.

In the SC article/circuit diagram/parts list they list:
Q1 as a 2N7002 N-channel Mosfet, and
Q2 as a IRML2244TRPBF P-channel Mosfet (both SOT-23 packages)

What the have supplied (both SOT-23) as listed on their packing slip is:
- a 2N7002P, it has "LWW 58" marked on it (I assume this is a P channel and not an N), and
- a DMP2215L-7, it has "22P-D8" marked on it.

Are they equivalents and which one is which?

(I would normally ask SC but it is a long weekend in Melbourne - some horse race on Tuesday)

Many thanks,

Andrew

TassyJim

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Joined: 07/08/2011
Location: Australia
Posts: 6283

Posted: 02:04am 03 Nov 2019

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The 2N7002P has a rating of 360mA while the 2N7002 is 300 mA so no problems there.

I can't find a datasheet for the IRML2244 and don't have the SC circuit but the DMP2215L-7 is a P-channel device so I assume is a suitable substitute,

Jim

VK7JH
MMedit

PeterB
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Joined: 05/02/2015
Location: Australia
Posts: 655

Posted: 02:06am 03 Nov 2019

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G'Day Andrew

using google gives

2N7002N is N chan
2N7002P is N chan
IRML2244 etc is P chan
DMP2215L-7 is P chan

Somebody will come back and say "no, the other way round"

Peter

Andrew_G
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Joined: 18/10/2016
Location: Australia
Posts: 871

Posted: 02:19am 03 Nov 2019

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Thanks Peter and Jim,
If I understand it correctly, I am OK to use:
- the 2N7002P instead of the 2N7002N as Q1 - because they are BOTH N channel
- the DMP2215L-7 as Q2 - because it is a P channel

What would happen if it is the other way round - smoke or just not working?

Thanks,

Andrew

PeterB
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Posted: 02:29am 03 Nov 2019

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It would depend on the circuit about which I know nothing.
Give it a try. The shops will be open again on Wednesday.
Only joking

Peter

TassyJim

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Posts: 6283

Posted: 03:02am 03 Nov 2019

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Quote - the 2N7002P instead of the 2N7002N as Q1 - because they are BOTH N channel

both N channel AND all other specs are more or less equivalent. The 2N7002P is an upgrade.

I can't compare spec for the other pair because I don't have a datasheet or the circuit.
I made a hopefully intelligent guess that all will be well.

VK7JH
MMedit

Andrew_G
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Joined: 18/10/2016
Location: Australia
Posts: 871

Posted: 03:51am 03 Nov 2019

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Thanks Jim and Peter,
Fingers crossed - I'm trying it out now - no smoke yet. But I haven't connected the LCD yet.

I can't get a ">" prompt back from a known programmed MM yet, LED flashes.
(Of course I'm using MMEdit . . .)

I'll keep looking for faults.

Cheers,

Andrew

Andrew_G
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Posts: 871

Posted: 03:57am 03 Nov 2019

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I guess a 28 pin MM socket does better with more than 2 pins soldered . . . Andrew

Andrew_G
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Posts: 871

Posted: 04:49am 03 Nov 2019

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Thanks Jim and Peter (et al),

All good with no smoke!
The 3.5" is a beautiful display, well supported by Peter Mather's driver and documentation.

With all the right connections made (eventually) it worked "almost out of the box".
(and the PWM brightness control works a treat)

Cheers,

Andrew

erbp
Senior Member

Joined: 03/05/2016
Location: Australia
Posts: 195

Posted: 04:54am 03 Nov 2019

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Hi,

The SC Micromite Backpack V2 (May 2017) used 2N7002 and DMP2215L-7 Mosfets for the backlight controller and I can confirm that they work in that version of the backpack. I don't have the circuit for the V3 backpack, but I would be surprised if the backlight circuitry changed significantly, so presumably the IRML2244 is compatible with the DMP2215L-7.

Cheers,
Phil.

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 7937

Posted: 09:15am 03 Nov 2019

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Just for reference, Digi-Key have the IRLML2244TRPbF and there's a link to the data sheet on their page:
https://www.digikey.com/product-detail/en/infineon-technologies/IRLML2244TRPBF/IRLML2244TRPBFCT-ND/2639575

The DMP2215L-7 is listed as obsolete, so it's no surprise that they've substituted something else. :)

Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs

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