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DOI: 10.1002/aelm.201901263 Organic light-emitting diodes (LEDs)are famous commercialized organic devices used as display modules in smartphones. However, other electronic components have not been completely replaced by organic materials yet because of the poor performance and lifetime of these materials. Several research groups have therefore focused their efforts on developing various electronic elements from organic materials such as electrodes, capacitors, inductors, memory, photovoltaic cells, sensors, transistors, and non-volatile memory for complex electronic devices.[15–17] Nevertheless, only a few organic electronic filters for circuits with noisy electric signals have been reported. A Schmitt trigger, one of the most commonly used versatile noise filters, consists of a comparator circuit with hysteresis that is induced by applying positive feedback to the non-inverting input of a comparator or differential amplifier. These characteristics of a Schmitt trigger allow the output signal to retain its signal until the input signal changes enough to change the trigger, hence use of the term “trigger.”[18] One of representative use of a Schmitt trigger is as an electric noise filter in integrated circuits. It is particularly effective in signaling conditioning applications such as increasing immunity to noise in circuits caused by contact bounce in switches or fluctuations from unpredictable output changes. Another use of a Schmitt trigger is an onebit analog-to-digital converter, which transform an analog input to a digital output signals using a low-to-high signal transition Although there have been many attempts to replace conventional inorganic electronics with organic materials that can be mass produced at low cost, few organic electronic filters to increase immunity to electrical noise have been reported thus far. Conventional Schmitt triggers or their inverters are used in many electronic circuits as versatile electronic noise filters. However, it is challenging to manufacture organic electronic systems with complex circuitry. In this study, a simple, all-solid-state organic Schmitt trigger consisting of twin two-in-one organic ferroelectric memory transistors with the same chemical compositions and device dimensions but different threshold voltages is introduced. Threshold voltages and hysteresis in the two-in-one devices can be controlled by polarization switching as demonstrated in a previous study. Hysteresis of a ferroelectric p-type depletion load inverter can be achieved using twin two-in-one devices when the sweep voltage is higher than the critical gate voltages. This facilitates inverter characteristics at two different threshold voltages, and realizing a Schmitt trigger. Finally, based on simulation program with integrated circuit emphasis (SPICE) simulation, guidelines are proposed on how to design organic Schmitt triggers with por n-type materials and ferroelectric or charge-trapping mechanisms to achieve inverting or non-inverting characteristics.