Teardown Tuesday: Amazon Kindle Fire TabletMarch 28, 2017 by Mark Hughes
The Amazon Kindle Fire tablet is a 7" color tablet. This Teardown Tuesday opens one up and looks inside.
The Amazon Kindle Fire tablet with Alexa is a 7-inch, $50 tablet that provides access to books, music, videos, voice-recognition, and web browsing. This Teardown Tuesday opens one up to see what's inside.
The Amazon Kindle Fire is held in a snap-closed plastic case. Begin disassembly by applying pressure to the seams of the case with a narrow plastic or metal tool. Once the case splits, use a small piece of plastic (such as a guitar pick) to keeps the sides separated while you work around the perimeter of the device.
The battery is held in place with several pieces of tape on the backside and attached to the main circuit board with a snap-fit connection. Disconnect the battery from the circuit board by prying from underneath the connector, and disconnect the battery by gently lifting from one side until the tape yields.
Use a heat gun or soldering iron to disconnect the LCD touchscreen from the circuit board and then use a screwdriver to remove all circuit board mounting screws. Disconnect the FPC connector to the LCD, and the main circuit board can be worked free from the case.
The two small stainless steel RFI shields will have to removed with a hot air or infrared heat source. The cover to the largest shield can be popped off, but the cross members underneath prevent access to the chips. The cross members can be safely cut out without damaging the device, or the entire framework can be removed with heat.
The circuit board for the Amazon Kindle Fire holds most of the components used in the device. The off-board components include the LCD, a speaker, the battery, and the touchscreen. With the exception of the Li-ion battery charger, all ICs on the circuit board are shielded from EMI interference by stainless steel enclosures.
Watch the process in the video below:
The front and reverse of the circuit board inside the Kinde Fire with EMI shielding removed to reveal the underlying ICs
|Top Side Marking||Description||More Information|
|I2C Controlled 3A Single Cell USB Charger||Datasheet|
|FBGA QDP NAND Flash Memory||Webpage|
|8GB LPDDR memory||Datasheet|
|Quad Core Table Platform||Webpage|
|Communication Chip (GPS, Wi-Fi, Bluetooth)||Datasheet|
The Kindle Fire components are mounted on a single multilayer circuit board. Hidden beneath the FPC cable for the front-facing camera is a 24-pad testbed that is used to ensure the camera is adequately attached and might offer additional programming or debugging information. Many of the chips are by a company named Mediatek but, unfortunately, datasheets are not readily available online.
All stainless steel covers and cross pieces have been cut out to increase visibility.
The front and reverse of the Kindle Fire circuit board with ICs of interest identified
The primary control IC on this device is (5) a Mediatek 8127a. ICs (3) and (4) are types of memory, and (6) handles wireless communication. ICs (1), (2), and (7) handle power management for devices on and off the board.
(1) BQ24296M (White)
This integrated circuit is responsible for battery charge management. This single-cell charger has reporting and control through Inter-Integrated Circuit (I²C) protocol. It is a switch-mode charger that operates at 1.5 MHz.
This chip is made by Texas Instruments and comes from the manufacturer with a great deal of documentation (website) and design tools (software). You can even purchase an evaluation module for this device. The level of transparency offered regarding this chip lies in sharp contrast with what I found with the other components.
bq24296M functional block diagram. Click to enlarge. Image courtesy of TI (PDF).
(2) MT6323LGA (Orange)
This power management IC provides three buck converters, 23 low dropout regulators, an audio amplifier, and LED driver circuits. It is controlled through Serial Peripheral Interface (SPI). The IC also has several General Purpose Input/Output Pins (GPIO). This is the same power management IC we found when we tore down the Amazon Echo Dot V2. The MT6323 also has the capability to control Li-ion battery charging, so why the engineers included the BQ24296M is a question that hopefully one of our readers with experience in Li-ion charge circuits can answer.
(3) Samsung KLM8G1GEND-BO31 (Red)
This Embedded Multi-Media Controller (eMMC) contains flash memory, an interface, and the flash memory controller on the same silicon die. It has the ability to store high-resolution video and offers high data transfer rates. The Samsung web page has it listed as 8 GB capacity. This is non-volatile storage memory that holds programs and files even when the device is disconnected from power for a long period of time.
(4) SEC 546 (Yellow)
This Samsung LPDDR3 DRAM is high-speed, low-power memory built specifically for smartphone and tablets. The Samsung web page has it listed as 8 GB capacity. This is faster memory compared to the item listed above, but it is volatile.
(5) MEDIATEK MT8127 (Green)
According to the MediaTek web page, this system-on-chip (SOC) integrates a quad-core ARM Cortex A7 MPCore (see its technical reference manual here), 13-megapixel camera ISP (image signal processor), DDR3 controller, and a high-definition 1080p video decoder. The GPU is an ARM Mali-450.
MT8127 functional block diagram. Image courtesy of Mediatek
(6) MEDIATEK MT6627N (Blue)
This communications chip compliments the MT8127 and offers GPS, Bluetooth, and Wi-Fi connectivity.
(7) APW 7276 (Magenta)
This TFT-LCD Power Driver provides power to backlight the LCD screen. The datasheet indicates that it has a 1.5 MHz switching frequency, two charge pump controllers, and a high-performance step-up converter (current-mode, fixed-frequency PWM).
Image courtesy of ANPEC (PDF)
Much like the Echo, the integrated circuits pdfs used in the Amazon Fire are difficult to source. But basic function of each of the chips can be determined from the information that is readily available online. This is an amazing piece of engineering for $50, so amazing that I wonder if Amazon sells these at or below cost. If you have additional insights into this device, please share them in the comments section below.
Next Teardown: Projector Alarm Clock with Humidity and Temperature Sensors