The Nexus One: Google hits a smartphone home run

More than a year after its unveiling, the Nexus One remains a leading-edge product, and represents a substantial leap in capability beyond the T-Mobile G1.

Brian Dipert, Senior Technical Editor -- EDN, February 17, 2011

About 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.


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.


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.