Earlier on, we showed you how the tiny USB “Nano Receiver” can be hidden away in the Gigabyte GM-KM7600 wireless mouse body. So small is the receiver, taking it apart felt like jewellery work to these butter fingers of mine. Here, you can see how small the actual circuitry of the receiver unit is.
On one side of the Printed Circuit Board (PCB), nearly half of the area is dominated by gold plated contacts designed to mate with a USB socket on your PC. The other half of it is rather bare, consisting a clock crystal and associated oscillator components. On the the extreme end of the PCB is a convoluted trace functioning as an antenna. Such miniaturisation is made possible by two Quad Flat No-leads (QFN) Integrated Circuits (ICs) and some ingenious engineering.
The larger QFN20 IC is a Nordic Semiconductor nRF24L01 “Single Chip 2.4GHz Transceiver.” This versatile component, as you will later see, is present in more than one part of the Gigabyte KM7600 “2.4GHz Wireless Deluxe Combo.” The smaller (QFN16) part is a SN8F2271 8-bit microcontroller (MCU) from SONiX.
Taking apart the Gigabyte GM-KM7600 wireless mouse is significantly less tedious. It actually uses fasteners (read: screws)! Three screws out, and there you have an open rodent.
Cleanly laid out, the disassembled Gigabyte GM-KM7600 wireless mouse had no obvious electromechanical or manufacturing flaws for us to pick at.
The imaging engine of the Gigabyte GM-KM7600 is pictured above. PixArt Imaging Inc.’s PAN3204 “Low Cost Wireless Mouse Sensor” is employed here. This part offers up to 1600 Counts Per Inch (CPI) resolution at a frame rate of 3000 Frames Per Second (FPS).
The left and right click buttons are Omron parts. The rotary encoder comes from Trantek Electronics.
The 28-pin Shrink Small Outline Package (SSOP) SN8P26L34 8-bit MCU from SONiX (again) is the logic glue holding the sensor and wireless transceiver togther.
At the edge of the PCB is a curvaceous piece of enamelled copper wire serving as the antenna, driven by Nordic Semiconductor’s nRF24L01 IC.