Game Gear Power board

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

I have developed a replacement power board specifically designed for the new SYF Mainboard. While its primary compatibility lies with the SYF Mainboard, it can also function with the original SEGA Game Gear under certain conditions.

It's important to note that this board is compatible with the original Game Gear, it does not include a 34V voltage regulator. Therefore, it will only function with an original SEGA Game Gear if the LCD screen has been replaced with a modern LCD TFT (IPS) kit.

The power board offers two power source options: a 3.7V LiPo battery or a USB-C connection. To prioritize power from the USB source, I have implemented a MOSFET load sharing circuit. When the USB is connected, it takes precedence, while simultaneously charging the LiPo battery using a Microchip MCP73833/4 battery management controller.

Given that the Game Gear requires a 5V power supply, I have chosen a TI TPS61032 step-up power regulator. This regulator efficiently converts the lower voltage to the required 5V. Additionally, it features a low-battery comparator that triggers a VREF change, enabling the low-battery indicator on the Game Gear.

DIP Switches (v1.5 - v1.7)

The DIP switches offer flexibility and customization, allowing you to tailor the power board's functionality based on your specific console version, battery charging capabilities, and LCD screen requirements.

The power board I have developed features three DIP switches that provide various options and functionalities:

    1. VA0 / VA1: This switch enables a more stable low battery indicator specifically designed for the original Sega dual-ASIC VA0 console. For the VA1 and all SYF mainboards, it is recommended to keep the switch set to VA1.
    2. 1.0A / 0.5A: This switch allows you to choose the maximum battery charging current. The appropriate setting depends on the capabilities of your USB-C power brick and the batteries you are using. If your power brick can deliver 1.5A and your batteries can handle 1.0A charging current, you can switch it to 1.0A. However, if you are unsure or using different specifications, it is recommended to keep the switch set to 0.5A.
    3. 34V / 5V: This switch is only available on the 34V version of the board. With this option, you can enable or disable the output of 34V to pin 9 of the connector. This feature is particularly relevant when using the board with the original SEGA Game Gear LCD, the requires 34V for the contrast circuit. Please note that this switch is not applicable to boards without a 34V voltage regulator

      Solderpad (v1.8)

      This solderpad enables a more stable low battery indicator specifically designed for the original Sega dual-ASIC VA0 console. For the VA1 and all SYF mainboards, it is recommended to keep it open. For an original Sega dual-ASIC VA0 mainboard, please bridge the 2 solderpads.

      LiPo battery recommendation

      I have been testing with the following sizes LiPo batteries:

        The 124050 is the maximum size that fits into the battery component. I strongly recommend a larger 2500-3000mAh battery in case you use a less power efficient LCD screen (McWill, RetroKai, Funnyplaying).

        Gerber

        In case you like to make your own board, you can download the gerber, BOM and PNP files here. Keep in mind the project has a Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) license.

        USB-C cover

        To cover the hole of the DC jack, you can 3D print this STL. I recommend you to print it with a transparent type of plastic, so the charging status LEDs will be visible.

        BOM

        Designator Value Footprint LCSC Part number
        C1 1uF 0603 C106248
        C2 100nF 0603 C14663
        C3 10uF 0603 C326057
        C4 1uF 0603 C106248
        C6 220uF CASE_B2 C79111
        C7 1uF 0603 C106248
        C8 1uF 0603 C106248
        C9 100nF 0603 C14663
        CN1 292161-9 Plugin C225342
        CN2 TYPE-C-31-M-29 SMD C2689969
        D1 PD3S230 DI323 C460243
        IC1 TPS61032 TSSOP-16 C88716
        IC2 MCP73833T-AMI/UN MSOP-10 C627668
        IC3 SN74LVC1G14 SOT23-5 C7835
        L1 6.8uH 6060 C280585 
        LD1 YELLOW-GREEN 0606 C264500
        Q1 AO3401A SOT-23-3 C306862
        R1 47K 0603 C105579 
        R2 51R 0603 C114628 
        R3 4.7K 0603 C99782
        R4 4.7K 0603 C99782
        R7 2.49M 0603 C482797
        R8 470K 0603 C114622
        R11 220R 0603 C107696
        R12 1.1K 0603 C137780 
        R13 1.1K 0603 C137780 
        R14 1K 0603 C22548 
        R15 470K 0603 C114622
        R17 1.8K 0603 C185354 
        R18 10K 0603 C98220 
        SW1 SSSF121900 Plugin C97449