There is no reference regarding N438HB1 on Chipworks site! Any help?
It seems DRAM is not any more inside processor Package-On-Package Module of A5X:
- the package is of different type
- existence of both DRAM packages
Thermal dissipation could have played role in making the decision to separate CPU and DRAM
Since iPad 2 it is known that:
- Apple PN 339S0130 means DDR2 dies are from Samsung
- Apple PN 339S0137 means DDR2 dies are from Elpida
Apple PN is on A5 package
It seems, there is another version of Apple A5 found in iPad 2:
- Apple PN is 339S0137 (instead of 339S0130 above)
- DRAM PN is Elpida B4064B2PF-8D-F (instead of Samsung K3PE4E400B-XGC1 above)
Clearly a new A4 version from Apple:
- different Apple PoP part number 339S0123 (original iPhone 4: 339S0108)
- different Samsung DRAM incorporated K4265J1PB-50-F (original iPhone 4: K4X4G643GB)
- same processor SoC die marked as APL0398
This is new version of Apple A4 processor, with PN 339S0108 (original A4 was 339S0084) and 512MB Mobile DRAM from Samsung (2xK4X4G643GB)
Re: AKM8975. The PN is actually AK8975/B - 3-axis Electronic Compass, Si-monolithic 3-axis geomagnetic sensor LSI
The exact PN of Intersil IC should be ISL97645AIRZ.
"Boost + VON Slice + VCOM", according to datasheet.
The APL0398 is Apple internal part number designation of new A4 SoC, one can find it on the die and within markings on the package.
The A4 predecessor found in iPhone 3GS is designated as APL0298, so A4 could be just next, optimized, version of APL0298 :-)
It seems A4 is not (yet) revolutionary product, but upgraded version of A8 based processor found in iPhone 3GS.
On FCC RAW data logic board photos of iPad it is clearly seen that the processor, not yet marked as A4 but in old, iPhone style, is manufactured during week 49 of 2009.
In addition, Apple part number of A4, APL0398, is quite similar (upgraded?) to original iPhone 3GS processor PN APL0298.