Digital-to-analog converter
AssigneeQUALCOMM Incorporated
InventorYi-Hung Tseng
Life of this patent
Estimating the term…
Abstract
Certain aspects of the present disclosure provide digital-to-analog converters (DACs). One example DAC generally includes a first transistor configured to selectively couple a power source to a load. In a first mode of operation of the DAC, the first transistor is closed and couples the load to the power source. In a second mode of operation of the DAC, the first transistor is open and decouples the load from the power source. The DAC further includes a current limiting circuit selectively coupled between the first transistor and a reference voltage. In the first mode, the current limiting circuit is decoupled from the reference voltage. In the second mode, the current limiting circuit is coupled to the reference voltage.
Claims30
A digital-to-analog converter (DAC) comprising:
- a first transistor configured to selectively couple a power source to a load, wherein in a first mode of operation of the DAC the first transistor is closed and couples the load to the power source, and in a second mode of operation of the DAC the first transistor is open and decouples the load from the power source;
- and
- a current limiting circuit selectively coupled between the first transistor and a reference voltage, wherein in the first mode the current limiting circuit is decoupled from the reference voltage and in the second mode the current limiting circuit is coupled to the reference voltage.
A method for operating a digital-to-analog converter (DAC), the method comprising:
- closing a first transistor of the DAC to couple a load to a power source;
- decoupling a current limiting circuit selectively coupled between the first transistor and a reference voltage from the reference voltage while the first transistor is closed;
- opening the first transistor to decouple the load from the power source;
- and
- coupling the current limiting circuit to the reference voltage while the first transistor is open.
An apparatus for converting a digital signal to an analog signal, comprising:
- a first transistor coupled between ground and a first node, a gate of the first transistor being coupled to a first control signal;
- a second transistor coupled between the first node and a load, a gate of the second transistor being coupled to a bias voltage;
- a third transistor having a gate and a source coupled to the first node;
- and
- a fourth transistor coupled between a drain of the third transistor and a power supply, a gate of the fourth transistor being coupled to a second control signal.
An apparatus for converting a digital signal to an analog signal, comprising:
- a first transistor coupled between a power supply and a first node, a gate of the first transistor being coupled to a first control signal;
- a second transistor coupled between the first node and a load, a gate of the second transistor being coupled to a bias voltage;
- a third transistor having a gate and a source coupled to the first node;
- and
- a fourth transistor coupled between a drain of the third transistor and ground, a gate of the fourth transistor being coupled to a second control signal.
Dependencies are inferred from the claim text.