Contributed by Gary Tomkins and Jim Morrison
The new iPad is Apple’s first device that uses 4G LTE and also supports multiband 3G. In fact, it supports 700 MHz and 2100 MHz LTE, UMTS/HSPA/HSPA+/DC-HSDPA at 850, 900, 1900, 2100 MHz (all 3G), and GSM/EDGE at 850, 900, 1800, and 1900 MHz. That is seven different radio standards and six different frequencies! And of course, it also has a Wi-Fi (802.11 a/b/g/n) transceiver and Bluetooth.
To do all of this takes a lot of silicon (and GaAs devices). In the 4G version of the new iPad, attached to the main board is a secondary board dedicated to the cellular radios. We counted 19 different major packages, 10 on one side and 9 on the other, and many that contain more than one die!
Apple's New iPad Cellular Board – Side 1
Apple's New iPad Cellular Board – Side 2
Let’s take a closer look at these RF components. Working from the right edge of side 1, we can see three antenna connections that make up the main antenna, the GPS antenna and the diversity antenna. (Antenna diversity is a technique that multiplexes the RF signals from a different antenna to improve signal quality in the receiver.) Connected to the antennas are Murata modules. Let’s discuss these one by one.
First up, we have a Murata device with package markings PFBA. This is a Murata PA (power amplifier) device. We have seen many Murata switch modules before, but a PA from Murata, this is news. The package is marked with Murata markings, but the major die inside carries Panasonic die markings. (It appears that Murata and Panasonic are collaborating on this device. How does that play with the recent Murata acquisition of Renesas’ PA group?)
Below are package photographs, X-rays, and die image of the Murata/Panasonic PA device. The Panasonic die is a single chip dual band PA and the x-ray shows two duplexers. In the X-Ray below, the primary Panasonic die can be identified by the wire bonds, and the other two GaAs dies are more opaque to the x-rays and show up as dark rectangles.
Murata/Panasonic PA Device Package Photograph
Murata PFBA PA Top X-Ray
Murata PFBA PA Side X-Ray
Murata/Panasonic PA Die Markings
Next up is the Murata package marked SWUA. This device is a Murata and Peregrine SP6T Rx diversity switch/module. Module is a more appropriate description for these components, as the X-rays clearly show that there is more than one device involved in making these modules work, but the heart of the device is the Peregrine SP6T silicon-on-sapphire switch die.
The last design win we had witnessed for Peregrine was the key win of the main RF antenna switch (an SP8T in a Murata antenna switch module) in the current iPhone 4s that was released in October 2011. Peregrine’s solution brings efficiency to the game over alternative solutions. Unlike GaAs devices that need separate external components for control and charge pump functionality, the silicon-on-sapphire (SOS) solution employed by Peregrine enables embedded switching, control logic, and voltage pumps on the same die as the switch array.
Murata/Peregrine SP6T Rx Package Photograph
Murata/Peregrine SP6T Rx Top X-Ray
Murata/Peregrine SP6T Rx Side X-Ray
Murata/Peregrine SP6T Rx Die Photograph
For some details on Peregrine’s design win in the first iPhone, and the background on their SOS technology, read one of our older blogs here.
On to the traditional PA suppliers, where the die are fabricated on gallium arsenide (GaAs) substrates (typically InGaP HBT and GaAs pHEMT devices) that still reign superior over silicon for this application because the power efficiency of these die significantly affect battery consumption. The GaAs HBT die are more efficient than current generation silicon-based power amplifiers.
First off, we have the TriQuint TQM7M5013, a quad-band 850/900/1800/1900 MHz GSM, GPRS, Edge PA module that contains three separate PA die.
TriQuint GSM PA Module Package Photograph
TriQuint GSM PA Module X-Ray
TriQuint GSM PA Module Side X-Ray
Next up, we have the Skyworks 77468-16, a band 8, 900 MHZ W-CDMA/HSDPA/HSPA+ PA and duplexer. The X-ray shows the PA die, duplexer, and impedance matching components co-packaged with the PA die.
Skyworks 77468-16 Package Photograph
Skyworks 77468-16 Top X-Ray
Skyworks 77468-16 Side X-Ray
Moving onto the Avago part, we see their Band 4 UMTS/LTE power amplifier module in the component marked A5904.
Avago ACPM5904 Package Photograph
Avago ACPM5904 Top X-Ray
Avago ACPM5904 Side X-Ray
Contained within the RF section of the iPad 3, we see a 1 Gb Micron SLC NAND flash. Given what Qualcomm is saying about the Gobi 4000 chipset, it requires, in addition to the MDM9600 processor and PM8028 power management IC, an external flash memory chip to hold the specific carrier profile to make the single Gobi hardware set work in any carrier environment and under any operating system (Windows, Android, or Apple OS).
Micron SLC NAND Flash Device
Also on this side of the cellular board is the Qualcomm RTR8600 LTE/UMTS/GSM transceiver. The die measures 6.55 mm x 3.95 mm and carries the die markings HG11-VF535-220.
Qualcomm RTR8600 Package Photograph
Qualcomm RTR8600 Die Photograph
The power management component for the transceiver is the Qualcomm PM8028. The die measures 5.83 mm x 3.11 mm. The PM8028 and the RTR8600 are very successful devices for Qualcomm, and have been observed by Chipworks in dozens of smartphones.
Qualcomm PM8028 Package Photograph
Qualcomm PM8028 Die Photograph
Qualcomm PM8028 Die Markings
That’s a lot of information to absorb, so here’s a summary:
Apple's New iPad Main Board Side 1 - Devices Identified
On the opposite side of the motherboard, we have another Murata component marked SPM QRD01. This device is the main RF antenna switch module with Murata package markings but inside, yet again, we have two Peregrine SP8T silicon-on-sapphire switches.
Murata SPM QRD01 Package Photograph
Murata SPM QRD01 Top X-Ray
Murata SPM QRD01 Side X-Ray
Murata SPM QRD01 Die Photograph
Murata SPM QRD01 Die Markings
Directly below the Murata/Peregrine ASM, we have an Avago ACPM7792 band 2 power amplifier module.
Avago ACPM7792 Package Photograph
Avago ACPM7792 Top X-Ray
Avago ACPM7792 Side X-Ray
Next to the Murata/Peregrine ASM, we have the Skyworks SKY77469-16 band 5 power amplifier module.
Skyworks SKY77469-16 Package Photograph
Adjacent to the Skyworks PAM, we have an Avago A5917 band 17 LTE power amplifier module.
Avago A5917 Package Photograph
The large device on side 2 is a Qualcomm MDM9600, the RF processor, another multichip package that contains a 512 Mb Samsung memory die co-packaged with the 90 mm² processor die.
MDM9600 Die Photograph
Samsung 512 Mb Device Die Photograph
Back on the main board, at the opposite end from the cellular board, we have the Wi-Fi and Bluetooth radio. This is integrated within the Broadcom BCM4330 802.11/Bluetooth/FM combination chip surrounded by a few smaller die; these are RF devices such as the GaAs pHEMT low noise amplifiers for 2.4 GHz and 5 GHz 802.11 channels that are made by Skyworks.
Broadcom BCM4430 Package Photograph
Skyworks Device Package Photograph
Skyworks Device Package Photograph 2
Skyworks Device Die Photograph
Skyworks Device Die Markings
The Apple iPad 4G LTE only services the North American 700 MHz and 2100 MHz LTE bands. With multiple standards for GSM, CDMA, and 3G, it is already complicated enough to manufacture worldwide compatible devices. (There are 16 UMTS channels used for 3G). With LTE, this will become significantly more complex with up to 43 channels. As you can see, the quantity of chips needed to make this happen is incredible. With the specialist RF devices needed to optimize signal and power efficiency, it is going to be a very difficult task to simplify this process.
