Hi welcome to Tear down! Tuesday Got the new Google Nexus 7 tablet in all its black glory. What's inside this thing? I'm glad you asked. You know what we say here on the Eev blog: Don't turn it on, take it apart and well. I Don't think we're going to get too many Phillips head screws on this sucker.

So out it goes. We need our spudger. I think that's probably all we're going to need. Couple of Clips on the outside should just pop off fingers crossed.

and yes, I'm using a metal spudger, not a plastic one. Suei just get my spudger in this top side here and you can see there just a couple of plastic Clips there plastic retaining clips and it looks like it's going to pop off. a treat. Hopefully that's the plan.

We're almost in. almost in. I Think it's just just needs a little bit more percussive maintenance. Tada I think I heard it.

Yeah, looks good. That's it. a that was supremely easy. Thumbs up to Google and no surprises really.

The battery takes up a good lot of the room. What is that? You know that's a good you know, 2/3 of the area or something like that. We got some beefy copper shielding up here to meet Emi compliance and that sort of stuff. Got another metal can chipset down here.

a small board. you know, a relatively small board which just L-shaped uh, wraps around there like that and I suspect um, that might be it because based on the thinness of the uh tablet which really, you know isn't uh much at all I think all we've got is the battery. the display is going to be directly under that, probably attached to the front panel and just this one L-shaped board they're going to have have all the circuitry mounted on that. Of course there will be a lot of systems um, system on chip integration in this thing, so I'd expect.

you know, not much in the chipset department at all. There'll be a couple, of, you know, uh Wireless uh, chipsets, external and stuff like that. but there'll be one main application processor and external memory and you know, not a huge amount more. And on the side of the unit here you can see tactile Dome switches four of them mounted directly on a flat Flex uh cable on an angle like like which match up.

We've got our power button here. We got our volume up and down and that one's actually labeled reset, but it looks like there's a hole there on the case for it, but uh, it hasn't been drilled out and on the other side here where it does have a small hole that goes through into there and I'm not sure what's going on there, whether or not there's another uh tax switch on the bottom side of that PCB down in there, that's another reset button perhaps. And on the same side of the case, just below that button, you can see the four external gold contacts there clearly for either an external Um accessory device and or, uh, remote serial interface for remote programming monitoring. Debugging: Factory Programming the firmware? Whatever it is.

Um, that is, uh, a hacker's delight. And you can see how they've got the main PCB here and they're just using those little uh Leaf contacts to go down to a what looks like a separate physical mounted thing uh, you know module for those four gold contacts. If you take a look around the board here, you can see these little spring contacts directly on the PCB These are for the three antennas they've got on the back of the case. You can see the three pairs of mating contacts here, and if we take a look at them, here's the nearfield antenna.

Uh, NFC Antenna Version 2.0 You can see the contacts, you can see the traces down in there, and there's your GPS antenna version 2.0 as well. And if we come over to here, what do we get? We get our Wi-Fi antenna version 3.0 So there you go. They're integrated into the back of the case. you can see we've got some, uh, more copper.

and you see, we've got more copper shielding on the back of the Uh case over here. So they''re really gone to town there in terms of our shielding. and if we try and pry our battery out here, it should in theory be just held down with a bit of double-sided tape. And that does look to be the case.

I Had to use a bit of Uh Force down around here. They used quite a very aggressive double-sided tape there, but it came off really essentially. No problems at all and that's a huge thumbs up. No planned obsolescence in this thing.

You can easily replace that battery and just you know, it's even got a connector. you can just pull the thing out and I'm sure you'll be able to buy third party batteries for this before you know it. Beautiful! And if we have a look at the battery pack here, it is an Isus Lithium Polymer Battery Pack C11 Me 370t Uh rated for it's a single cell of course, rated for Uh 3.7 volts at Uh 4325 Mah hours or 16 WS Beautiful and clearly down in here. On the side there I can feel it and I can kind of see it down through there.

They've got a battery protection PCB which is absolutely essential for Uh Lithium Polymer uh batteries so you don't abuse them, don't overcharge them, don't uh, over discharge them, and uh, so they don't explode basically and that will be good quality. Um, you know, uh, professional, uh. protection circuitry in this device, not just some uh, slap together one hung load cheapy and the EU obviously rate things differently cuz in the EU it's 4170 milliamp. go figure.

And down here you'll notice that the micro USB and the 3.5 mm uh phone jack they're actually mounted on separate boards. So uh, in theory, if they, uh, wear out I know the micro USB is rated to, you know, many thousands of Uh Cycles but still, if these wear out, um, in theory, you could probably replace them and in the speaker Department Here, they do actually have dual speakers there. we go boing and it looks like to get at these devices under these metal shielding cans here. we're going to have to take off the stickers and then pry the cans off.

Get the trusty Swiss army knife under there and we should be able to lift off that can. No problems at all. TDA And this is going to be our GPS chipset. Dead giveaway goes to the GPS antenna terminals here and there it is.

It's a Broadcom BCM 4751 if we jump on over here to the Broom website BCM 4751 Here it is. It's an integrated monolithic Uh Gnss receiver, so it supports both GPS and Glosas as well, which is the Uh Russian counter part to the GPS. So obviously they're uh, maybe targeting the Russian Market here and up. Here it says accurate realtime navigation and improve sensitivity in urban Canyon environments.

Ah, love the term Urban Canyon but give me real Canyons any day of the week Anyway, it um, it claims that you know low power consumption uh, ultra low power tracking modes And it's got a build-in Ldo as well which of course reduces your bomb cost and they make a point of um, doing that that. Of course, because you know systems integration stuff, you're looking to lower your biller materials cost in these sort of things. If you're trying to eek out every cent having an L, you know a voltage regulator in there means you don't have to provide a local one and uh, you know you still, uh, probably need the bypass cap there of course for the Ldo, but still. you know you're saving a few cents there.

Try and get under the other shielded can here. They really gone to town to ensure that these things pass here. I Tada Oh, there we go. It's uh, just a shielded top.

and it contains a cage solded directly solded onto the PCB. And what we've got here is our Wi-Fi antenna here. So that looks like it's going to this chipset. And this chipset here is for the Uh nearfield Communications antenna and for the Wi-Fi We've gotten a zoo wave Aw NH 65 and I've had to use my mantis microscope to get a look at this one and it's very hard to read the brand on there, but I can.

Uh, definitely. if I get it at the right angle, it's an uh inven sense um, Mpu 6050 And here we go. let's check it out. It's a 6 AIS uh, gyro accelerometer, men's motion tracking chip.

Beautiful! And if you go through the marke in Spiel uh. the world's first and only Sixaxis Motion tracking device designed for low power, low cost, high performance smartphones, tablets, and wearable sensors. It contains inven sensors, motion fusion, and runtime calibration firmware. Beautiful that eliminates cost uh, costly and complex selection, qualification, and system level integration of discrete devices.

Beautiful once again. more system on chip stuff. They're really integrating all this stuff together. and uh, it combines a three AIS Gyroscope and 3axis acceler on the same die uh together with a Uh digital motion processor as well.

So it's not just your usual you know, uh, serial Um output accelerometer or analog output Mems Accelerometer. What? you might be used to? Um, you know, cheap as chips? this one's got Uh built-in processor as well. Uh, capable of processing complex 9 AIS motion Fusion Algorithms M Sounds complex and it has an external I Squar C bus as well for an external magnetometer. So this claims to have a magnetometer in it, so that must be an external I Squ C device on the board somewhere.

Um, it's a Qfn footprint as we saw and uh, it looks quite nice for precision tracking to both fast and slow algorithms. Part feature: User programmable gyro full range plus - 250 up to plusus uh 2000 per second Um, and a user programable acceleration range from 2G to Plusus 16g. Beautiful. And it uh, works at 3.8 million amps, presumably down at 3.3 Vols if you have a look over here, it's got uh uh low power operating modes 10 microamps at 1 Hertz um, up to 140 microamps at 40 htz and uh, it contains a 5 microamp idle mode as well and it's the I squ uh C interface um up to 400k or a 20 MHz SPI as well.

Excellent and it's tolerant up to 10,000 G's of shock which sounds like a lot but when you you know if you drop this thing onto, you know a hard concrete or steel surface on its Edge and the plastic is coupled directly through to the printed circuit Bo which is connected solded directly onto the chip. You can um in theory uh easily exceed that uh 10,000g uh shock uh rating and damage the device. and it also contains a built-in uh digital out temperature sensor as well and a sink capability Supports electronic Um image stabilization and GPS so it can. You know sync and track together with your GPS Brilliant! And it's smart enough to generate an interrupt as well for gesture St type stuff when you're panning, zooming.

um, you know a free fall interrupt. Oh no, it's falling. You know the device is falling quick. Do something like I don't know what you know actually.

uh, play a a wave file it says catch me, catch me I don't know. There you go. Um, it's got zero motion detection as well attached. uh tap detection Shake detection.

So um, all these things? Um, can interrupt the CPU and then you know so the CPU doesn't have to be continually processing this sort of stuff. It's all done on the processor on this chip, freeing up the resources from the main processor. uh, which allows it to detect all these you know, user interactions with the device. Excellent.

Well worth having. Well worth paying, you know? Um, you know, 50 cents or a dollar more for compared to you know, discreet um, acceler omers and stuff like that. And for our nearfield, Communications We've got an Nxp PN 65 and Nxp seem to be getting a few design wins for this Uh chipset. It's also used in the Samsung, Galaxy, Uh, S3 and others, so it's almost becoming a bit of a little deao standard for nearfield communications there.

I Suspect when we lift up all this stuff and even if I did unscrew this board, I'm not sure if I'm going to do it. but uh I wouldn't expect there be anything on the bottom side of the board. Why? CU You got a fair bit of you know area on top of here. This is more than enough uh Square surface area for all of the processing and all the sensing required for one of these tablets.

so no reason to go double-sided load. and it's got a high highest brand Uh 072 Wx2 display. That's the Uh IPS display 1280 by 800. And if we peel off some of this black tape holding in down this flat Flex cable here going to the display, then we get another metal can there which we can lift the skirt on that and have a look.

Looks like we got power supply circuitry so nothing terribly uh, surprising or interesting in there for the Uh switch mode power supply. Apart from the shielding of course, uh, you know, full metal can shielding? You don't want your DC Todc converter to be SP out any garbage it' be you know, high frequency one a megahertz or more it' be you know, Quite efficient, optimized for the power consumption of this Uh device. so you know I'd expect you upwards of like 90% efficiency something like that. And inside there I aspired a Texas Instruments TPS 63020 And yeah, there you go up to 90% Uh efficiency.

Maximum 3 amp out output current at 3.3 volts um you know and 2. amps output at VN is 2.5 so that'll be like the lowest point of the lithium ion rechargeable or Lithium Polymer batteries sorry so that'll be the sort of you know, the top end to the low end of the battery voltage. So it's anywhere from 3 amps at the maximum battery voltage as you know VN 3.6 And as the battery uh drops, the maximum Uh output current available is only 2 amps. and of course that's a buck boost uh topology as well because the battery voltage uh as it drops from say 3.6 volts to 2.5 Vols input.

you got to maintain that 3.3 volts output. So the input voltage can be above or below the regulated output voltage. So you even need a Sepic Uh converter or you know, a Buck Boost topology. And here's an efficiency versus output Uh Current graph here and you can see the Uh efficiency from 0 to 100% on the Y-axis in the output current.

uh from basically uh, nothing up to 4 amps and they would have chosen this device extremely carefully. Um, not only based on cost, that may not have even been a major factor. they probably would have wanted maximum efficiency because battery life in a product like this is you know, can Uh can kill you? It can kill your Market if you're you know, got an hour less battery life than the new iPad or the new other you know, xbrand, uh tablet Then you're going to get killed. So it's worth spending.

you know as whatever you need to to get a DC Todc converter to match your requirements and you want the utmost inefficiency. So they would have chosen this device based on uh, mostly. You know most of the decision would have been based on the operating point. The operating current you know would have been around the peak of this curve.

Here the efficiency curve. So they'd be getting you know uh, 85 to over 90% efficiency with this thing. Um, and that's how you design these sort of products to meet your target market. And the one on the right here of course is the one for the just the main operation.

Power save mode is disabled, but this one on the left power save mode enabled. Also, when the things powered down. Um, it's also got various efficiencies that's actually pretty darn good over a quite a range of low output currents there. I Really like it.

so you can bet your bottom dollar that the Uh design Engineers would have just poured over these data sheets and they would have you know dozens and dozens of different DC to DC converters to choose just the right perfect one. You know they're up to midnight reading these graphs and the efficiency curves and you know, trying to pick the best bang for Buuck Chip. They can get trade-off between cost and efficiency over your various operating modes which they would have known. You know they would have done tests on this system.

they would have known and when they're uh, trying to design the final board for production, they would have had um, uh, current, uh targets and they would have. You know all these things matter in terms of and when the battery voltage drops, you know, when it's above, when the battery voltage is above the Uh output voltage. What's the efficiency when it's below? when the input voltage is below the output voltage. What's the efficiency and power down? Oh, and you know, as a some poor design engineer um, power design engineer at Uh Isus probably you know spent a month pouring over these bloody data sheets and if we peel back our main foil here um, which was a bit of a pain, but I managed to get it out.

We got our main Nvidia processor and the memory and some more power supply stuff. and down in the power supply section here: Maxum Have a design win! It's the Max 77 612a but somewhat curiously I Couldn't find any info on that one on the Maxim website, but clearly it's some sort of power Management controller and we have a date code on the silk screen here 20th week 2012 and the process is a bit of a beast. It's an Nvidia who you usually associate with uh, just graphics cards and Graphics uh processors. It's a Uh T30 Lgra and if you have a look here at the corners, they've actually gunked that down.

They've epoxied the corners of the chip down uh to really keep this in place and they've done that on all four corners. and that's a quad core Arm Cortex processor working up to a maximum of 1.2 GHz And here we've got our SD Ram split into two different devices. Here they're in El Pider uh brand and that's DDR3 memory and it seems like I was a little bit off on the single-sided load. Uh, comment here.

Clearly theyve uh there's extra circuitry on the bottom because we missing the uh flash memory as well. There's got to be a couple of flash devices in there the 8 and the 16 gig. and I think if I look under the board here I can see extra circuitry on the bottom and we're missing um, other stuff like the uh, touchscreen uh controllers as well. Really? Um, I'm running out of time and uh, really? I don't want to, uh, tear down this any further I want to put it back together, rush home, let the wife play with it.

Um, hopefully if I haven't killed it and uh, so I w take the board off. As you can see, it's a rather interesting, uh construction. they've got, you know, a um, uh shazzy in there to keep the uh battery in place. they got the L-shaped board.

They haven't really wasted a lot of space in this thing. uh, they've tried to keep it as thin as possible I'm not sure uh, what's going on with this over here, but yeah, it's um, quite. It's very well built. they they certainly haven't uh, cut, uh, any cost at all and they've really knocked uh the EMC on the head.

They've done a really good job there and the all the Uh antennas integrated in the top of the case. I didn't find an RFID chip in there by the way. Uh, haven't uh, maybe you know I don't think there is one. Anyway, it's all been a rather interesting tear down and I hope you liked it and if you want to discuss it, uh, jump on over to the Eev blog Forum The links right there and remember if you like tear down Tuesday Please give it a big thumbs up.

Catch you next time you little Ripper Not a problem.