Vizio VTAB1008

From OLPC
Revision as of 06:33, 15 February 2012 by Wad (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

The Vizio VTAB1008 is a commercially available tablet in the USA.

Overview

The Vizio VTAB1008 is almost identical to the XO-3, from a software point of view. It uses the Marvell Armada 610 and provides 512MB of memory and 4GB of eMMC storage.

Display

Display

The display size is 8" diagonal w. 4:3 aspect ratio. The resolution is 1024x768.

There are three internal speakers, independently wired, and an internal mono microphone. The speakers are configured to provide stereo in either portrait or landscape mode.

Connectivity

The VTAB has 802.11b/g WiFi and Bluetooth, using a single antenna.

Location/Movement

The VTAB has both full GPS and an accelerometer.

Ports

  • One USB OTG
  • One mini HDMI output
  • One microSD card, externally accessible (pry out the tab on the bottom edge near the USB/HDMI. ports)

Power

The VTAB has a 22Wh Li-Ion polymer battery.

It consumes roughly 3.9W while idling, 4.5W while recording video, and 6.2W peak, from the battery.

It generally pulls around 7W from the adapter while charging.

The Vmain voltage to the SoC (on the unit tested) is 1.4V at full voltage, around 1.25V in a low power mode, and finally around 1.0V for idle. It jumps between voltages constantly, indicating full voltage/frequency scaling.

Breakdown

The tablet first breaks down into a bottom half containing the vast majority of the electronics and a top half consisting of the sandwich of touchscreen and display:

Bottom Half Top Half Display Sandwich

Electrically, the tablet consists of a main PCB, two auxiliary PCBs, and the display sandwich.

Vizio interconnects.png

Height

The tablet thickness is roughly 12.8mm in the middle. The height stackup is:

Height Stackup
Cover Glass: 1.0mm
Touchscreen: 0.9mm
Air Gap: 0.8mm
Display: 3.7mm
Swell gap: 0.4mm Main PCB: 4.8mm
Battery: 4.7mm
Back cover: 1.3mm
Touchscreen

The touchscreen is a multitouch projected capacitance screen, built with two layers of ITO on the piece of glass mounted inside of the cover glass (not quite single glass technology). An insulating material is placed between the two layers when they cross. The insulating material can be seen as a grid of dots when held at the wrong angle in sunlight. The air gap is created by a rim of black foam, 0.8mm in height, placed right outside the active area of the display (mostly on the bezel).

The back cover has a cheap cast metal heat spreader, bonded to the outer plastic shell.

Weight

The tablet weight is roughly 580 grams. This breaks down as:

Weight
Cover Glass/Bezel: 147g
Display: 179g
Main PCB: 45g
Battery: 116g
Back cover and side PCBs: 94g
Total: 581g

BOM