CURRENT TYPE D/A CONVERTER, DELTA SIGMA MODULATOR, AND COMMUNICATIONS DEVICE

摘要

This D/A converter includes a plurality of D/A converter elements, each comprising current sources configured to supply output currents to output nodes, and first switches configured to control the output currents. The output nodes are connected to a capacitor section having second switches and a capacitive load. The D/A converter further includes a switch control circuit configured to control the first switches responsive to digital signals, and also control the second switches in accordance with the control of the ON/OFF state of the first switches.

主权项

1. A current type D/A converter comprising a plurality of D/A converter elements and performing D/A conversion of a digital input signal, wherein
each of the D/A converter elements includes: a current source configured to supply output current to an output node; and a first switch configured to control the output current by switching between electrically connected and disconnected states, the current source and the first switch being connected in series to each other, an output node of at least one of the D/A converter elements is provided with a capacitor section including a capacitive load and a second switch connected between the capacitive load and the output node, and configured to switch between electrically connected and disconnected states, the D/A converter further comprises a control circuit configured to control the ON/OFF state of the first switch responsive to the digital input signal, and control the ON/OFF state of the second switch in accordance with the control of the ON/OFF state of the first switch, and the control circuit controls the ON/OFF state of the second switch such that the D/A converter reduces a magnitude of variation in an error-representing electric charge which is to be transferred to the output node.