David Carey, President, Portelligent (www.teardown.com)
TechOnline

Enabling the hands-free conversation now required of chatting drivers by a growing list of states and countries, the Motorola HS810 puts local wireless technology to work in a Bluetooth headset that collapses to a tidy 5cm. x 3cm. x 2cm. package. Unfold the boom microphone—which also turns the unit on—and flip out a hook for over-the-ear wearing and the HS810 makes for a reasonably comfortable package at a modest 20 grams. Volume Control buttons can be remapped for left or right ear and a slow pulsing blue (of course) light even comes on to alert others when you are on-call. Shipping with selected retail packages of Motorola's popular V600 handset, the Bluetooth device can automatically link and interact with up to eight other devices that are Bluetooth 1.1 compliant.

Analog technology figures prominently in the HS810 implementation, despite a fairly short component list. Central to the design is a single-chip Bluetooth component from Cambridge Silicon Radio (CSR) which integrates both digital baseband and RF radio into a single slice of CMOS technology. A 1M Byte NOR flash chip is adequate to hold the system software stack and presumably user-specific information related to desired headset-host pairings.

But the radio link is of no use without an interface to the audio world, so a Motorola MC145483 13bit CODEC provides the needed bridge between CSR's chip and speech input/output. A National Semiconductor LM4862 audio amplifier boosts CODEC output to drive the internal earpiece speaker while the microphone connects directly to the CODEC.

A Li-Ion rechargeable battery the size of an overgrown piece of Chiclet gum provides juice for a claimed talk and standby time of up to five hours and 100 hours respectively, with a TI BQ24010 Charge Management chip keeping recharge currents in line. A TI stepdown DC-DC converter and Ricoh LDO Regulator translate battery voltage to needed bias levels for the HS810 design.

With an estimated manufacturing cost well south of $20 and a $100 street price, the HS810 is at once a highmargin item and a gadget that can be bundled into Motorola's premier phone packages with relative ease. Though still suffering in audio quality compared to a wired headset, the sheer convenience of "fiddle-free hands-free" makes Bluetooth a worthwhile addition to your arsenal of cell phone accessories. So remember that analog technology makes it happen and then kiss that unfathomable ball of spaghetti from your wired headset goodbye.

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David Carey is President of Portelligent. The Austin, Texas company produces teardown reports and related industry research on Wireless, Mobile, and Personal Electronics. (www.teardown.com)