1. Switch-off part
Reducing power dissipation is important for the mobile device which is supplied by batteries;the switch-off part is to prevent the leakage or residual light line after switch off.(1)SH1106,the new promoted IC,is Self-boosting and self-switch-off,the other IC such as SSD1305 and SSD1306,need to add switch-off circuit
(2) SSD1306 is with self-boosting circuit but without the switch-off part, so it needs to add a switch-off part between the "VBAT" pin and VDD power pin
(3)The other IC, such as SSD1305 without a boost circuit and switch-off circuit, needs to add a booster circuit with the switch-off part.
Related: PMOLED which use SSD IC
The following circuit on the left side is the switch-off part
2. Booster circuit and the related components
Some IC need to add another booster circuit, to provide a 9 V-13V DC Volts for the VCC(or VPP) of the screen. The volts are different for the same IC with the different module;
Tips for booster circuits,
(1) Switch-off part is necessary
(2) Wire Wound chip inductor is the best choice(L601 in the picture above) , otherwise there will be a big current fluctuation when the DC-DC circuit is working
(3) How to choose a booster DC-DC IC;
If the component density is high, such as a smart watch and phone, we recommend XC9119D, with the stronger anti-interference ability; RT9284 can be used in the common situation
(4)The capacitor for the output pin needs a tantalum capacitor(c619 in the up picture), the withstand voltage must reach the requirements on the datasheet.
(5) The configuration of DC-DC components:
The components related to the DC-DC circuit must fix center on the boosting IC Booster, close to each other; It is best to best keep a distance from the receiver and other power amplifier circuits.
(6) You must set up the voltage of VCC according to the module datasheet, not according to the IC datasheet; the Same kind of IC corresponds to different modules, but the voltage of each glass module is different.