Question

A 4-bit Reduced-Resistance-Ratio D/A Converter, as shown in Figure 1, is used in an electronic system. w 1 to 4R 4R XXX < M 3R (... Figure 1 A 4-bit Reduced-Resistance-Ratio D/A Converter You are asked to modify the circuit in Figure 1 to design a 6- bit Reduced-Resistance-Ratio D/A Converter for a new electronic system. (a) Draw a diagram to show the 6-bit Reduced-Resistance-Ratio D/A Converter. (10%) Analyse and justify the components required in the 6-bit converter and calculate the D/A converter output voltage. (25%) Calculate the feedback resistor value of the 6-bit converter, if the maximum output voltage Vout = Vret. (8 %) (d) If a 5-bit D/A converter is required, can you design it using Reduced-Resistance-Ratio D/A structure? What would be the better structure which can be used to design a 5-bit D/A converter among Binary Scaled D/A converters? (7 %)

Answer 1

the resistance place in such way that from the next step it parrallel connection is 3R show w six identical resistance between them a 3R resistance the converted circuit is given bellow

Is 99 Twtta 3R .V.

Va voltage is the in this case is 1/6 vr that is desired thing

how it will come assume the bit sequence applied to this circuit that is 100000 in this case other signal are connected to zero except the b6 the circuit diagram is looked like this

b6 SAR w 3R 3R VA (-V.

final circuit diagram is as shown the voltage across bo V is 3/5Vr now the using using the gain equation we will get a value of the Rf =24Rf

the refrence voltage is doubt full here in my opinion for 4 bit it may 3/7vr total please check it

x x R

this circuit give five divesion 2R and 3R and last component come 2R so this will act for 5 bit