List of top Analog and Digital Electronics Questions asked in GATE Biomedical Engineering

For an 8-bit Digital to Analog Converter (DAC), the binary input 0000 0000 results in 0 V, and 1111 1111 results in 5 V. The output of the DAC for an input of 1011 0111 is ________ (in volts, rounded off to two decimal places).

An ideal opamp with an infinite gain and infinite bandwidth is connected in feedback as shown below. The output voltage \(V_o\) for the given input voltages in the circuit is ________ V (accurate to one decimal place).

In the circuit diagram shown below, BJTs are biased with \(V_{EB} = 0.7\ V\). Neglect the base current for operating point calculations. Assume infinite input and output impedance for the BJTs. The output voltage \(V_o\) with small input voltage \(v_i = 10\ mV\) is ______ mV (rounded off to one decimal place). The thermal voltage \(V_T = 25\ mV\) at room temperature.

The magnitude of the current gain \(\frac{I_{\text{load}}}{I_{\text{in}}}\) in the circuit below is ______ (rounded off to two decimal places).

In the circuit diagram shown below, the MOSFET is biased in the saturation region. The MOSFET has a threshold voltage \(V_{th} = 0.5 \, V\), width \(W = 100 \, \mu m\), length \(L = 0.1 \, \mu m\), and \(\mu_n C_{ox} = 100 \, \mu A.V^{-2}\). Assuming \(v_i = 1 \, mV\) as a small-signal input to MOSFET, the magnitude of the output voltage \(V_o\) is ______ mV (accurate to two decimal places). Ignore channel-length modulation for the MOSFET.}

A filter is designed using opamps, resistors, and capacitors as shown below. Opamps are ideal with infinite gain and infinite bandwidth. If \( \frac{V_o(s)}{V_i(s)} \) is an all-pass transfer function, the value of resistor R2 is _________ kΩ.

In the circuit diagram shown below, the logic gates operate with a supply voltage of 1 V. NAND and XNOR have 200 ps and 400 ps input-to-output delay, respectively.
At time \( t = T \), \( A(t) = 0 \), \( B(t) = 1 \) and \( Z(t) = 0 \). When the inputs are changed to \( A(t) = 1 \), \( B(t) = 0 \) at \( t = 2T \), a 1 V pulse is observed at \( Z \). The pulse width of the 1 V pulse is _________ ps.

Input bits X and Y are added by using the combinational logic as shown below. S represents the sum of the two bits. For a correct implementation of the sum, the signals \(D_0, D_1, D_2, D_3\) are _________, respectively.

In the circuit shown below, the output voltage \(V_{out}\) is \(\underline{\hspace{1cm}}\) V.

In the circuit diagram shown below, NMOS is in saturation region, \( \mu_n C_{\text{ox}} = 200 \, \mu \text{A/V}^2 \), width \( W = 40 \, \mu \text{m} \), length \( L = 1 \, \mu \text{m} \), the threshold voltage is 0.4 V, and the ratio of body-effect transconductance (\( g_m b \)) to transconductance (\( g_m \)) is 0.1. A small input voltage \( v_{\text{in}} \) is applied at the bulk-terminal to produce a small change in the output voltage \( v_{\text{out}} \). The dc gain for \( v_{\text{out}} / v_{\text{in}} \) is \(\underline{\hspace{2cm}}\). (Neglect channel-length modulation for NMOS and all intrinsic capacitors.)

In the circuit diagram shown below, all OPAMPs are ideal with infinite gain and bandwidth. \(\frac{V_{OUT}}{V_{IN}}\) for this circuit is \(\underline{\hspace{2cm}}\).

In the block diagram shown below, an analog signal, \( V_{IN} = \sin(2\pi \cdot 10^6 t) \) is quantized by a 10-bit Nyquist ADC. Later, 4 LSBs are dropped and 6 MSBs are converted to an analog signal \( V_{OUT} \) while using a 6-bit DAC. Assume uniform distribution for the quantization noise. The peak SQNR at the output of DAC is \(\underline{\hspace{2cm}}\) dB.

In the circuit shown below, Y is a 2-bit (Y\(_1\)Y\(_0\)) output of the combinational logic. What is the maximum value of Y for any given digital inputs, A\(_1\)A\(_0\) and B\(_1\)B\(_0\)?