Huawei Ideos S7

The Huawei Ideos S7 is a commercially available tablet in the USA.

Overview

The Huawei Ideos S7 provides 256MB of memory and 8GB of eMMC storage

Note: The Huawei Ideos S7 Slim is a different design, which incorporates more battery and uses a projected capacitance touch screen.

Display

The display size is 7" diagonal w. 16:9 aspect ratio. The resolution is 800 x 480. A single point resistive touchscreen is integrated.

There are two internal speakers, independently wired, and an internal mono microphone.

Connectivity

The Ideos S7 has 3G, 802.11b/g WiFi and Bluetooth, using three individual antennas.

Location/Movement

The Ideos S7 has an accelerometer.

Ports

• One micro USB OTG (power output only)
• One multipin connector, use undefined (docking ?)
• One microSD card, externally accessible
• One DC input port
• One stereo Headphone Jack (3.5mm)

Power

The Ideos S7 has a 8.2Wh Li-Ion polymer battery (3.7V @ 2200mAh).

There are three contacts to the battery, spring loaded and soldered directly to the main motherboard.

The battery is hard-sided, and roughly the size of two typical cell-phone batteries. There is no space allocated in the system design for battery swell, but the battery is heavier and larger than an equivalent-size soft-sided one. As the battery pack is easy to remove and replace, this is probably a good idea.

Breakdown

The tablet has a steel back plate which removes to allow access to the battery, SIM card, and manufacturing diagnostic ports. There is a larger plastic back cover which removes to allow access to the motherboard. Removing the back cover requires removal of six T-6 screws under the steel plate (hidden under plugs as well) and four T-6 screws in the front (hidden behind the flexible black plastic glued to each side of the display). The metal front bezel then pries away from the plastic back portion.

Electrically, the tablet consists of a motherboard, two auxiliary flexible PCBs (front facing camera, light sensor, and input buttons), the display and the touchscreen. The motherboard mainly consists of a 45mm x 60mm processor module, which contains the SoC, DRAM, 3G, and Bluetooth circuitry. This is manufactured using a high density interconnect PCB w. tightly controlled impedance. The main motherboard provides additional peripherals and system connections.

The design uses almost no wires, with the connections to the antennas, speakers, and microphone being made by gold-plated leaf springs mounted on the motherboard. The two auxiliary flex PCBs connect to the motherboard using high pitch board/board connectors and then route to the outside of the front bezel to directly support the front facing camera, indicators LEDs, ambient light sensing, and four input buttons.

In the area of the motherboard underneath the display (most of it's area), there are no components mounted and most of the surface is plated in gold (the remainder has soldermask). This contacts a conductive mesh bonded to the steel frame around the display.

Height

The tablet thickness is roughly 15.8mm in the middle. The height stackup is:

Height Stackup

Touchscreen: 0.5mm
Cover Glass: 1.1mm
Air Gap: 1.7mm
Display: 5.9mm
Steel frame: 0.8mm		Battery: 5.9mm
Motherboard: 4.5mm	Camera: 4.5mm
Back plastic: 1mm
Steel Back Plate: 0.8mm

The back-facing camera is mounted on a flex cable attached to the motherboard using a board/board connector, then it mounts in a cut-out in the motherboard allowing room for a lens the size of the one used on the XO.

Weight

The tablet weight is roughly 510 grams. This breaks down as:

Weight

Cover Glass/Touchscreen/Bezel:	130g
Display:	152g
Motherboard:	64g
Battery:	52g
Back cover:	106g
Total:	504g

BOM

• Main motherboard breakdown
• QSD8250 Snapdragon SoC