| 摘要 |
In one example, a current sampling circuit comprises a current sampling transistor, a capacitor arrangement between the gate and source of the current sampling transistor and an amplifier provided in a feedback loop between the gate and source of the current sampling transistor. A switch controls the circuit to sample a gate-source voltage corresponding to a current being sampled onto the capacitor arrangement. The capacitor arrangement comprises a first capacitor circuit for sampling a gate source voltage in a first sampling phase and a second capacitor circuit, with the first and second capacitor circuits arranged for together sampling the gate source voltage in a second sampling phase. The operating point of the amplifier is shifted between the first and second phases based on the gate source voltage sampled in the first sampling phase. This arrangement provides a coarse sampling phase, which is used to change the operating conditions of an amplifier used within the circuit. This means the amplifier can operate more efficiently in a subsequent fine tuning sampling phase. |
