Abstract:
Integrated device (202) for use in a monostable circuit (200), the integrated device (202) having a programming terminal (103) able to be linked to external resistive means (Rext) so as to programme the duration of a non-stable state of the circuit (200) and comprising a comparator (120) having a first (+) and a second (-) input terminal and an output terminal for generating an output signal (Vout) of the circuit (200), capacitive means (C) linked to the first input terminal (+) of the comparator (120) so as to apply thereto a voltage (Vc) correlated with the voltage on the capacitive means (C), control means (SW,115) linked to the first input terminal (+) of the comparator (120) so as to switch the circuit (200) to the non-stable state, and means (M1, M2) for sending a current (Iref1) which passes through the resistive means (Rext) to the capacitive means (C), in which the programming terminal (103) is linked to the second input terminal (-) of the comparator (120) so as to apply thereto a voltage (Vref1) correlated with the voltage on the resistive means (Rext).
Abstract:
A circuit for charging a capacitance (C) by means of an LDMOS integrated transistor (LD) functioning as a source follower stage and controlled, in a manner to emulate a high voltage charging diode of the capacitance via a bootstrap (Cp) capacitor charged by a diode (D1) connected to the supply node (Vs) of the circuit, by an (IO1) inverter driven by a logic control circuit in function of a first Low Gate Drive Signal and of a second logic signal (UVLOb) which is active during a phase where the supply voltage (Vs) is lower than the minimum switch-on voltage of the integrated circuit, comprises further a second inverter (M1, M2), functionally referred to the charging node of said bootstrap (Cp) capacitor and to the voltage of the output node (A) of said inverter (IO1) and having an input coupled to said second logic signal (UVLOb) and an output coupled to the gate node of said LDMOS transistor (LD), for preventing accidental undue switch-on of the LDMOS transistor.
Abstract:
The present invention refers to a method for scanning sequence selection for displays. In one embodiment of the method for scanning sequence selection for displays having a plurality of rows and columns, said plurality of rows and columns cross each other defining a plurality of optical elements having a first optical state and a second optical state in response to a first electric state and to a second electric state. The method comprises the phases of driving said plurality of row of said display according to a prefixed scanning ordering. The method is characterized in that said prefixed scanning ordering is predisposed by ordering every column of said plurality of column so that the total switching number between said first electric state and said second electric state is minimized.
Abstract:
Herein described is a driving method for LCD modules having a multiplicity of display elements placed in the intersections of a matrix having a plurality of row electrodes and a plurality of column electrodes. The method comprises a first phase for scanning all the row electrodes of said matrix in an interval of scanning time (NT). The first phase comprises a second phase comprising the generation of a first signal suited to energizing at least one row electrode of the matrix for a first preset interval of time (T), the generation of second signals (C3(t), C5(t)) suited to energizing respectively each column electrode of said matrix simultaneously with the energizing of at least one row electrode. The second signals (C3(t), C5(t)) are suited to determining the grey level of each display element of at least one row electrode energized by means of an alternance of corresponding values distinct signal levels (Von, Voff, V1-V3) for intervals of time (T1on, T1off) comprised in the first preset interval of time (T) by means of a first PWM modulation. The first preset interval of time (T) is lower than the interval of scanning time (NT). The first phase comprises a third phase successive to the second phase and comprising the generation of another first signal suited to energizing at least another row electrode of said matrix for a second preset period of time (T) equal and successive to the first preset interval of time, the generation of third signals (C3(t), C5(t)) suited to energizing each column electrode of the matrix simultaneously to said at least another row electrode; the third signals are suited to determining the grey level of each display element of at least another row electrode energized by means of an altemance of values corresponding to said distinct signal levels (Von, Voff, V1-V3) for intervals of time (T2on, T2off) comprised in said second preset interval of time (T) by means of a second PWM modulation. The second PWM modulation is such to ensure the continuity of the signal level of said second signals (C3(t), C5(t)) and third signals (C3(t), C5(t)) in the passage from the first preset period of time (T) to the second preset period of time (T). (Figure 5).
Abstract:
The present invention refers to a supply system of the driving voltage generator of the rows and of the columns of a liquid crystal display. The supply system comprises first and second generator circuits (D3,D4) which output respective prefixed voltages (V3,V4). Each generator circuit receives two supply voltages. The first generator receives, via one voltage supply terminal, a first voltage (VLCD). The second generator receives, via one voltage supply terminal, a second voltage (GND). The other supply terminals of the generators are each connected to a charge storage device (CTNK), e.g. a capacitor, which acts as a charging tank. Charge stored in the capacitor is shared by both generators, and a control circuit (CONT) causes the voltage across the capacitor to lie within a predefined range.