Repeat Problem 11-20 using the measured data given in Table 11-12.

Table 11-12

Data from Problem 11-20

A certain DAC has the following specifications: eight-bit resolution, full scale = 2.55 V, offset ≤ 2 mV; accuracy = ±0.1% F.S. A static test on this DAC produces the results shown in Table 11-11. What is the probable cause of the malfunction?

Table 11-11

Input Code 00000000 00000001 00000010 00000100 00001111 10000000 Output 20.5 mV 30.5 mV 20.5 mV 60.6 mV 150.6 mV 1.300 V