Sensing Circuit with Reduced Bias Clamp

摘要

A sensing circuit having a reduced bias clamp and method of operating the sensing circuit are provided. The sensing circuit may include a reference path and a sensing path. The sensing path may include a first transistor, clamping capacitor and a pair of switches. The reference path may include a second transistor, clamping capacitor and another pair of switches. A common gain stage receiving a bias voltage charges the clamping capacitors for the respective paths in a charging mode. The clamping capacitors may be charged in a serial or partially parallel manner during the charging mode. Each path may be coupled to a comparator, which may sense current or voltage changes between the paths during a sense mode. The sensing circuit may be configured to provide for sensing current or voltage changes between multiple sensing and/or reference paths in a parallel or serial manner.

主权项

1. A circuit comprising:
a gain device having a first input and a first output; a comparator having a first input, a second input and a first output; a first transistor having a first control terminal, the first control terminal of the first transistor coupled to a first terminal of a first capacitor and a first terminal of a first switch, the first switch having a second terminal coupled to the first output of the gain device, the first transistor having a second terminal coupled to the first input of the comparator, the first transistor having a third terminal coupled to a first terminal of a second switch, the second switch having a second terminal coupled to the first input of the gain device; and a second transistor having a first control terminal, the first control terminal of the second transistor coupled to a second capacitor and to a first terminal of a third switch, the third switch having a second terminal coupled to the first output of the gain device, the second transistor having a second terminal coupled to the second input of the comparator, the second transistor having a third terminal coupled to a first terminal of a fourth switch, the fourth switch having a second terminal coupled to the first input of the gain device.