Design Con 2015

The Nexus One: Google hits a smartphone home run

-February 17, 2011

The Nexus One: Google hits a smartphone home run imageAbout 17 months ago, EDN dissected Google’s first Android-based and developer-intended handset, the HTC-designed T-Mobile G1, that Google had released roughly one year earlier (see “Google’s Android OS emerges,” EDN, Sept 17, 2009, pg 22). About two months ago, Google unveiled its fourth-generation developer smartphone, the Samsung-developed Nexus S. Between these bookends, two other HTC-crafted devices, the Google Ion, or ADP2 (Android Developer Phone 2), and the Nexus One, emerged. Google last year sold the Nexus One directly to consumers in a six-month experiment. As a partnership project with iFixit shows, the Nexus One represents a substantial leap in capability beyond the G1 (see “Nexus One Teardown”). More than a year after its unveiling, it remains a leading-edge product, both in an absolute sense and relative to its Nexus S successor.

The Nexus One: Google hits a smartphone home run figure 11. Like many of its HTC-developed contemporaries of the era, the Nexus One leverages a Samsung-manufactured OLED (organic-light-emitting-diode) display. Crisper and touting richer colors than a conventional LED-backlit LCD (liquid-crystal display), its comparative downsides include washed-out images in high-ambient-light environments, greater power consumption than LCDs in some situations, and limited availability. OLED-supply shortcomings prompted HTC to subsequently redesign several handsets for LCDs (see “Display-technology advancements: Change is the only constant,” EDN, Dec 15, 2010, pg 24).

2. Synaptics supplies the Nexus One with the same ClearPad 2000 touchscreen and controller technology as that in the Sony Ericsson Xperia X10 mini The Nexus One: Google hits a smartphone home run figure 2and many other touch-augmented mobile electronics devices (see “Sony Ericsson’s Xperia X10 mini: the teardown skinny,” EDN, Aug 26, 2010, pg 20, and “A magic touch: The concept’s sound, but implementation options abound,” EDN, Nov 4, 2010, pg 26).

3. The primary system PCB’s underside showcases a Samsung MCM (multichip module) encompassing 512 Mbytes of NAND-flash memory and 512 Mbytes of mobile SDRAM. Power-management ICs include Qualcomm’s PM7540 and Texas Instruments’ TPS65023, and Skyworks’ SKY77336 tackles the GSM (global-system-for-mobile)-communications power-amplifier function. Google sold Nexus One versions that supported both AT&T and T-Mobile’s 3G (third-generation) cellular-data frequencies in the United States. Google initially also planned a Verizon-cognizant CDMA (code-division-multiple-access) variant but decided a few months later to reference-sell the HTC Droid Incredible instead.

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4. The primary PCB’s topside includes Qualcomm’s RTR6285 RF-transceiver IC and 1-GHz, first-generation QSD8250 Snapdragon application processor, which integrates cellular modem and GPS (global-positioning-system) functions. The QSD8250 also includes the proprietary Adreno graphics core that the company acquired from Advanced Micro Devices’ ATI Graphics division. The QSD8250 is a variant of the ARM Cortex-A8 architecture, thereby supporting the ARM Version 7 instruction set, but Qualcomm’s ARM architectural license gave Snapdragon’s The Nexus One: Google  hits a smartphone home run figure 4-5engineers additional design flexibility to—at least on paper—deliver multimedia performance higher than that of a conventional Cortex-A8 SIMD (single-instruction/ multiple-data) multimedia product.

5. Between the two Qualcomm devices is the Audience A1026 audio processor. This IC works in conjunction with two Knowles Electronics MEMS (microelectromechanical-system) microphones; one resides on the handset’s underside to capture the user’s voice, while the other is located on the back—to the left of the 5M-pixel still camera lens and associated flash—and focuses on ambient environmental sounds. Whereas conventional beam-forming techniques simply subtract ambient noise from the voice input to enhance the perceived quality of the input on the other end of the cellular connection, Audience’s more complex Computational Auditory Scene Analysis approach mimics how the human auditory system operates, thereby justifying a dedicated silicon engine in the Nexus One design. Other manufacturers, such as Motorola and Verizon, with the Droid, instead shoehorn the voice-processing algorithm onto the application processor. A speakerphone transducer resides in the handset backside’s upper-right corner.

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 Read More Prying Eyes and for more on the Google Nexus One, visit Brian's Brain.
6. The Nexus One one-ups Apple’s iPhone series and many other modern handsets by integrating Broadcom’s BCM4329 wireless transceiver, which supports 802.11n-transfer-speed enhancements, albeit only in the 2.4-GHz band. The iPad, iPhone 4, and third-generation iPod touch also use the BCM4329, but Apple hasn’t yet unlocked the chip’s beyond-802.11g capabilities. The BCM4329 also handles the Nexus One’s Bluetooth 2.1 and EDR (enhanced-data-rate) support, but Google hasn’t yet harnessed the chip’s FM-transmitting and -receiving features. Instead, hackers have migrated code from the similarly equipped HTC Desire to begin the unsanctioned and incomplete process of adding FM-radio capabilities to the handset.

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