A digital-to-analog converter uses a reference voltage of 120 V dc and has eight binary digit precision. In one of the sampling instants, the data contained in the binary register = 01010101. If a zero order hold is used to generate the output signal, determine the voltage level of the signal.

Answer: Vo = 39.84 volts

Explanation:

Let Vo to be the voltage level of the signal,

Therefore,

Vo = 120{0.5 (0) + 0.25 (1) + 0.125 (0) + 0.0625 (1) + 0.03125 (0)

+ 0.015625 (1) + 0.007812 (0) + 0.003906 (1) }

Vo = 39.84 volts

Given Information:

Reference voltage = Vr = 120 Volts

Number of bits = 8

Required Information:

Analog voltage at 01010101 = V = ?

Answer:

V = 39.84372 Volts

Explanation:

Binary Register: 0 1 0 1 0 1 0 1

V = Vr*[ 2⁻¹ (0) + 2⁻² (1) + 2⁻³ (0) + 2⁻⁴ (1) + 2⁻⁵ (0) + 2⁻⁶ (1) + 2⁻⁷ (0) + 2⁻⁸ (1) ]

V = 120*[ 0.5 (0) + 0.25 (1) + 0.125 (0) + 0.0625 (1) + 0.03125 (0) + 0.015625 (1) + 0.007812 (0) + 0.003906 (1) ]

V = 120*[ 0.25 + 0.0625 + 0.015625 + 0.003906]

V = 120*[ 0.332031]

V = 39.84372 Volts

Therefore, the analog voltage corresponding to binary register 01010101 is 39.84372 Volts