Crack Analog Design Interview: Whiteboard Rounds & GATE ECE

Apply the superposition theorem to analyze circuits, understand capacitor roles, and determine cutoff frequencies in an active rc filter. Explore bridge circuits, negative feedback, and op-amp applications.

Identify the pulse generator function in an XOR–RC circuit, analyze rising and falling edge delays, and show how 50% vs 70% thresholds affect pulse width and single-edge output.

Master fundamentals of rc circuits, learn how to compute current and voltages in simple resistor networks. See how voltage division and feedback use these circuits in analog design and interviews.

Explore voltage division with two resistors across different voltages, derive the difference voltage, analyze current, and see practical uses in differential feedback and feed forward circuits.

explore the step voltage response of an analog RC circuit, showing capacitor charging and discharging with a time constant, and how parasitic resistance causes lag.

Learn how adding a capacitor across a circuit speeds up step voltage responses in high speed analog design, reducing charging time and improving rise times in RC configurations.

Learn how ideal op-amps act as voltage-controlled voltage sources with a virtual short between inputs. Recognize zero input current and high open-loop gain that guide circuit solving.

Explore how an op-amp with finite open-loop gain deviates from the ideal virtual ground, deriving relationships between V+, V-, and Vout in feedback circuits.

Explore how output saturation breaks the virtual short in an op-amp circuit and determine the input offset voltage, around -0.5 V, with practical implications for design.

Calculate the diode’s small-signal current using a parallel junction capacitance and a small-signal model, incorporating the thermal voltage (26 mV) and ideality factor, in a dc-plus-sinusoidal input circuit.

Apply superposition to op-amp circuits: compute each input's output with other sources zero, analyze both inverting and noninverting configurations, then sum the contributions.

Apply the superposition theorem to analyze an op-amp inverting configuration, determining the partial outputs from V1 and V2 and combining them for the final output.

Explore applying the superposition theorem to an op-amp circuit with two sources, computing the total output as the sum of individual responses using voltage division.

Explore how to apply the superposition theorem to an op-amp circuit, analyzing an inverting amplifier to derive the output using multiple sources.

Apply Kirchhoff's current law at the op-amp inputs to determine the output voltage, using the ideal op-amp assumptions of zero input current and a virtual short between the inputs.

Apply KCL to an ideal op-amp inverting configuration to derive output voltage from input and feedback currents, solving for resistor values including 1 kΩ via two 10 kΩ paths.

Apply ideal op-amp assumptions and use the virtual short to equate equations, solving for the output voltage in a single-input analog design problem.

Analyze an op-amp with two voltage inputs under ideal assumptions, apply negative feedback and the superposition theorem to compute input currents and the output voltage.

Explore a two-input op-amp circuit using the superposition theorem, review ideal op-amp assumptions, and derive the output response to multiple input sources.

Explore a switch-capacitor circuit where a constant charging current flows into the capacitor, producing voltage by integration. Learn about virtual ground, ideal versus practical sources, and saturation mitigation in filters.

explain how an ideal op-amp with feedback yields a constant current into a capacitor, causing a linear voltage ramp until saturation, and discuss ways to avoid saturation for high-frequency operation.

Determine whether a speaker uses a woofer or tweeter by analyzing low vs high frequency outputs in filters. See how capacitors and inductors shape bass and treble in speaker design.

Explore ring oscillators built from three common-source and CMOS inverters, with three phase inversions and unity feedback, where per-stage gain >=2 enables sustained oscillations via RC delays.

Examine the sources and impact of noise in a ring oscillator, including wire bond and pad interfaces, effective capacitance, and the resulting carrier frequency and sideband noise.

Explore how controlled oscillators use voltage or current to stabilize frequency with kvco and the linear relation f = f_naught + kvco·input, defining the frequency tuning range.

Learn calibration of sensors using one point and two point methods to derive corrected values from raw and reference ranges, addressing offset and linearity in oscillator-based systems.

Demonstrates a zener-based voltage regulator using negative feedback and virtual ground to regulate a 12 v input to a 4.7 v reference, and guides selecting r1 and r2 values.

analyze a bridge circuit in an op-amp feedback configuration to compute the output voltage for a delta of 0.05, using virtual ground and current division across symmetric branches.

Analyze zener diode breakdown voltage in an analog design, examine off and on modes, and determine input voltage range from 20 V to 36.62 V to keep the zener regulated.