Contactless Interface
First Claim
1. A circuit comprising:
- an input configured for coupling to an antenna and for receiving an alternating voltage from the antenna;
a rectifier circuit coupled to the input, the rectifier circuit operable for rectifying the alternating voltage;
a shunt coupled to the rectifier and operable for regulating the rectified voltage; and
a second regulator circuit coupled to the shunt and operable for receiving the shunt current and using the shunt current to output a first regulated voltage.
3 Assignments
0 Petitions
Accused Products
Abstract
Power extracted from an antenna inductively coupled to an alternating magnetic field is regulated to provide voltage supplies. In some implementations, a first voltage supply (e.g., 3.8 volts) provides regulated voltage to analog circuits and a second, lower, voltage supply (e.g., 1.4 volts) provides regulated voltage to digital circuits. The first voltage supply is regulated, using shunt regulation, by a first voltage regulator circuit. The second voltage supply is regulated, using a series regulation, by a second voltage regulator circuit. The second voltage regulator circuit is supplied by the shunted current from the first voltage regulator. Excess shunt current provided by the first regulator circuit can be bypassed (e.g., bypassed to ground). The second voltage regulator circuit can use a timer circuit to control the amount of charge transferred to a second voltage supply rail. The timer circuit can compensate for different currents from the first voltage regulator circuit.
14 Citations
10 Claims
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1. A circuit comprising:
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an input configured for coupling to an antenna and for receiving an alternating voltage from the antenna; a rectifier circuit coupled to the input, the rectifier circuit operable for rectifying the alternating voltage; a shunt coupled to the rectifier and operable for regulating the rectified voltage; and a second regulator circuit coupled to the shunt and operable for receiving the shunt current and using the shunt current to output a first regulated voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification