Granted Patent B2

US 9,035,691 · App. 14/044,772 · Granted May 19, 2015

Inventor: Wolfgang Roeper (Heilbronn, DE)

Assignee: Atmel Corporation

H03K17/302H03K17/162H03K17/687H03K2217/0054

Abstract

Claims (16)

1. A circuit comprising:

a switching transistor having a gate, drain and source;

a coil coupled between the source and drain of the switching transistor;

a ground rectifier coupled in parallel with the coil; and

a diode coupled between the gate of the switching transistor and a supply voltage.

2. The circuit of claim 1 ,

where the ground rectifier includes a switch configured to couple opposite ends of the coil to ground.

3. The circuit of claim 1 , further comprising:

a trim capacitor or resistor coupled to the drain of the switching transistor.

4. The circuit of claim 1 , where the circuit is included in a key fob.

5. The circuit of claim 1 , further comprising:

one or more capacitors coupled between the gate and a voltage source.

6. The circuit of claim 1 , further comprising:

a tuning capacitor coupled in parallel to the coil.

7. The circuit of claim 5 , where the voltage source is a fully rectified alternating current (AC) voltage waveform.

8. The circuit of claim 1 , where the supply voltage is a battery.

Assignments (18)

Continuity (1)