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name: designing-electronic-circuits
description: Designs electronic circuits from requirements through testing. Use when you need circuit topology selection, component specification, schematic creation, or testing procedures for electronic systems.
---

Electronic Circuit Design

1. Define requirements: Input voltage, output voltage, current, frequency range
2. Select topology: Linear regulator, switching converter, amplifier type, etc.
3. Choose key components: ICs, passives, protection elements
4. Create schematic with proper annotations
5. Specify test points and verification procedures

Circuit Design Process:

Progress:

• Requirements analysis (power, signal, environmental)
• Topology selection and trade-off analysis
• Component selection with margins and availability
• Schematic capture with proper labeling
• Critical design calculations (power dissipation, stability)
• Test plan definition
• Design review checklist

Component Selection Criteria:

1. Electrical specifications (voltage, current, frequency, tolerance)
2. Package requirements (size, thermal, pin count)
3. Environmental ratings (temperature, humidity)
4. Cost and availability constraints
5. Manufacturing considerations

Example 1: 5V to 3.3V Linear Regulator Input: Need 5V to 3.3V conversion, 500mA max current Output:

• Topology: LDO regulator (AMS1117-3.3)
• Input cap: 10µF tantalum
• Output cap: 22µF ceramic + 100nF ceramic
• Dropout: 1.2V max, suitable for 5V input
• Test: Load regulation 0-500mA, thermal verification

Example 2: Op-amp Inverting Amplifier Input: Amplify 0-1V signal by -10x, single supply operation Output:

• IC: Rail-to-rail op-amp (OPA2340)
• R1: 1kΩ (input), R2: 10kΩ (feedback)
• Bias: R3=R4=5.5kΩ voltage divider for Vcc/2 reference
• Supply bypass: 100nF + 10µF per supply pin
• Test: DC sweep 0-1V input, verify -10V to 0V output

Schematic Standards:

• Use standard symbols and consistent grid spacing
• Label all components with values and part numbers
• Include test points at critical nodes
• Add supply decoupling near every IC
• Show pin numbers on complex ICs

Component Margins:

• Voltage: 2x minimum safety factor
• Current: 50% derating minimum
• Power: 50% derating for reliability
• Temperature: Consider worst-case ambient + self-heating

Design for Manufacturing:

• Prefer common component values (E12/E24 series)
• Avoid obsolete or single-source parts
• Consider component tolerances in worst-case analysis
• Include assembly notes for critical orientations

Circuit Topology:

• Don't use linear regulators for high power conversion (>2W dissipation)
• Avoid op-amps near unity gain without compensation considerations
• Never float unused op-amp inputs
• Don't forget pull-up/pull-down resistors on digital inputs

Component Selection:

• Don't ignore package power dissipation limits
• Avoid ceramic capacitors for audio applications (microphonics)
• Don't use electrolytic caps in high-ripple current applications
• Never exceed absolute maximum ratings, even briefly

Testing Oversights:

• Not testing at temperature extremes
• Ignoring power-up/power-down sequences
• Forgetting to verify protection circuits actually work
• Not checking EMC considerations early in design