摘要:
Two parallel regulator stages, each comprising a transistor (T1, T2, respectively), are provided. The transistor (T2) forms part of the indirect parallel regulator stage and acts directly on the rectifier. It is capable of taking up comparatively large currents and hence is comparatively slow. The transistor (T1) forms part of the direct regulator stage and operates in parallel with the sustaining capacitor. Because of the coarse control provided by the transistor (T2), it need take up small currents only and can hence have a very fast control behavior. Because of the coarse control by the transistor (T2), the alternating voltage on the antenna terminals (LA and LB) quickly breaks down when the RF signal is interrupted; consequently, the transmission rate can be increased in the case of pause interval modulation. Static discharges are also dissipated by the transistor (T2), so that no additional protective circuitry is required for this purpose.
摘要:
A data carrier (1) which can be operated in a contact-bound mode and in a contactless mode and a circuit (1A) for such a data carrier (1) has supply voltage generating means (35) for deriving a supply voltage (VDD), for various circuit sections of the data carrier (1) and of the circuit (1A), from a received useful HF signal (HF), and, in addition, potential equalizing circuit (94) by which at least two contact terminals (17A, 19A) each connected to a respective transmission contact (17, 19) can be brought at the same potential (ground).