The present invention relates in one aspect to an auxiliary charge pump for a RFID rectifier, the charge pump, which comprises a first charge pump stage (11; 111) connected to an input (14; 114), a second charge pump stage (12; 112) connected to the input, a diode clamp (13; 113) connected to an output (15; 115), and a regulating transistor (16; 116) having a gate connected with an output (21; 121) of the first charge pump stage and having a source and a drain, wherein one of the source and the drain is coupled to the diode clamp. In further aspects the invention relates to a RFID transponder, to a multistage rectifier and to a rectifier stage comprising such an auxiliary charge pump.

The present invention relates in one aspect to an auxiliary charge pump for a RFID rectifier, the charge pump, which comprises a first charge pump stage (11; 111) connected to an input (14; 114), a second charge pump stage (12; 112) connected to the input, a diode clamp (13; 113) connected to an output (15; 115), and a regulating transistor (16; 116) having a gate connected with an output (21; 121) of the first charge pump stage and having a source and a drain, wherein one of the source and the drain is coupled to the diode clamp. In further aspects the invention relates to a RFID transponder, to a multistage rectifier and to a rectifier stage comprising such an auxiliary charge pump.

The present invention relates to a transponder, which comprises an antenna and a multi-stage rectifier. The antenna is connected to an input of the multi-stage rectifier having m rectifier stages, and a shunt limiter is connected to an output of the rectifier and connected to an n.sub.th stage of the multi-stage rectifier, wherein n<m.

A hybrid document includes a flexible document having visible markings. One or more light-controlling elements and a controller are embedded in or on the flexible document. The controller is electrically connected to the one or more light-controlling elements to control the one or more light-controlling elements. A power input connection is electrically connected to the controller, or one or more light-controlling elements, or both. A power source can be connected to the power input connection, for example a piezoelectric or photovoltaic power source. In response to applied power, the controller causes the one or more light-controlling elements to emit light. In some embodiments, the controller includes a memory and a value can be stored in the memory and displayed by the light-controlling element(s). In some embodiments, the value can be assigned or varied by a hybrid currency teller machine.

An internal voltage generator of a smart card and a smart card including the same. The internal voltage generator may include: a mode detector that generates a mode signal indicating a contact mode or a contactless mode; a low-drop out (LDO) regulator including an error amplifier, where the LDO regulator is responsive to the mode signal to: in the contact mode, drive the error amplifier with a second driving voltage to generate an error voltage, and regulate the second driving voltage based on the error voltage to generate a first output voltage, and in the contactless mode, drive the error amplifier with the first driving voltage to generate the error voltage, and regulate the second driving voltage based on the error voltage to generate the first output voltage.