D/A Converter

The R-2R ladder network is preferred in DACs over a binary-weighted resistor DAC because:

• It uses fewer resistors

• It can be integrated on-chip easily with matched resistor values

• It operates at higher currents

• It reduces the need for switches

What is the primary function of the "2R" resistor in the R-2R DAC ladder?

• To match the input voltage

• To ensure equal current splitting and maintain linearity

• To limit the power consumption

• To shift the output voltage level

One drawback of an R-2R ladder DAC in industrial applications is:

• Difficulty of integration

• High power dissipation

• Sensitivity to resistor mismatch

• Lack of scalability to high resolution

In a voltage-mode R-2R DAC, the output is taken from:

• The current sink

• The summing node of the resistor network

• The reference ground

• The positive supply rail

Current-mode R-2R DACs are advantageous in high-speed applications because

• They are cheaper to manufacture

• They consume more power

• Current switching is faster and less affected by parasitic capacitance

• They don't require calibration

Voltage-mode R-2R DACs are commonly used when:

• Output impedance must be low and driving voltage is needed

• Low current operation is mandatory

• Power loss is acceptable

• Driving high-capacitance loads

In CMOS DACs, digital switches are implemented using:

• Diodes

• BJTs

• Transmission gates (CMOS pass transistors)

• Phototransistors

The primary requirement for a switch used in a high-resolution DAC is:

• High-speed switching

• Low cost

• Low on-resistance and low leakage

• Ability to drive large inductive loads

In a current-mode R-2R DAC, switches are used to:

• Charge capacitors in sequence

• Select which resistor carries current to ground or reference

• Amplify the output

• Boost the resolution

Which issue can cause glitches in DAC outputs during switching transitions?

• Power supply filtering

• Capacitor mismatch

• Simultaneous switching of multiple bits

• Clock jitter