Abstract: An identification transponder (IDT) for transferring an identification code (IDC) to a base station (BS) by means of varying an RF-signal transmitted by the base station (BS) in a rhythm which corresponds to the identification code (IDC). The identification transponder (IDT) comprises means (IDCG) for the generation of the identification code (IDC); rectifying means (RTF); and a load transistor (TL). The load transistor (TL) is arranged in such a manner that it performs two tasks: the task of rectifying the RF-signal (thus it substitutes a diode function in the rectifying means (RTF)), and the task of supplying a variable load to the rectifying means (RTF). The variable load varies in said rhythm. As a consequence the input current of the rectifying means (RTF) is varied in said rhythm which in turn varies the RF-signal. This variation in the RF-signal is detected in the base station (BS).

Abstract: A DC/DC up/down converter (10), comprising first and second input terminals (20, 21); first and second output terminal (30, 31); a coil (L); first switching means (S1) operatively connected to provide a conduction path from said first input terminal (20) to said coil (L) second switching means (S2) operatively connected to provide a conduction path from said first switching means (S1) and said coil (L) to said second input terminal (21); third switching means (S3) operatively connected to provide a conduction path from said coil (L) to said first output terminal (30); fourth switching means (S4) operatively connected to provide a conduction path from said coil (L) and said third switching means (S3) to said second output terminal (31); control means (11) operatively connected for controlling said switching means (S1, S2, S3, S4); reference voltage means (12) for providing a reference voltage (Vr); and comparator means (13) for providing a comparison signal (Vc) for said control means (11) in response to compa

Abstract: A DC/DC converter (10; 30; 40; 50; 60), comprising inductive energy storage means (2), switching means (S0-S7) and control means (9; 31; 41; 51; 61), wherein said control means (9; 31; 41; 51; 61) are arranged for selectively operating said switching means (S0-S7) for providing electrical energy from said energy storage means (2) to an output (A; B; C; D) of said DC/DC converter (10; 30; 40; 50; 60) in both a Pulse Width Modulation (PWM) mode and a Pulse Frequency Modulation (PFM) mode switching cycle.

Abstract: A converter for converting an input voltage (Ui) into an output voltage (U0). The converter has several modes of operation. The converter can, for example, operate in an up-conversion mode, a down-conversion mode, or a window conversion mode. The converter has at least one switch (S1-S4) for controlling the converter so as to obtain a desired value of the output voltage (U0) in the up-conversion mode and in the down-conversion mode. This is achieved by changing the duty cycle of a binary signal (BS) which controls the switch (S1-S4). The converter further includes means (DMNS) for detecting the duty cycle of the binary signal (BS). This duty cycle is compared with a reference duty cycle (RFDCCL). The result of this comparison is used for deciding whether or not to change over from the up-conversion mode (or the down-conversion mode) to the window conversion mode. In the window conversion mode each switch (S1-S4) in the converter is permanently closed or open.