STMicroelectronics Analog ICs

Op-amp selection depends on key parameters: Bandwidth - choose unity-gain bandwidth 10x your signal frequency

Slew rate - ensure SR > 2π × f × Vpeak for undistorted output

Input offset voltage - critical for precision DC applications (choose <1mV for 12-bit accuracy)

Supply voltage - verify rail-to-rail input/output requirements if needed

Quiescent current - important for battery-powered applications. ST offers specialized families: TS for general purpose, TSV for low voltage, and precision series for instrumentation.

Define your signal characteristics and accuracy requirements first. Contact our analog specialists for selection guidance.

Rail-to-rail op-amps can handle input signals and produce outputs that extend close to the supply rails (typically within 10-100mV). Standard op-amps have limited input common-mode range (often 1-2V from rails) and output swing (1-2V from rails). Rail-to-rail input (RRI) allows signals near both supply rails. Rail-to-rail output (RRO) enables maximum dynamic range. Full rail-to-rail (RRIO) is essential for low-voltage battery applications (1.8V-3.3V) to maximize signal range.

Use rail-to-rail devices for low-voltage battery applications. Standard op-amps are sufficient for higher supply voltages.

Minimize noise through multiple techniques: Select low-noise op-amps (en < 10nV/√Hz) for front-end stages

Use proper PCB layout with separate analog/digital grounds

Implement star grounding and minimize ground loops

Use decoupling capacitors (100nF + 10uF) close to supply pins

Keep high-impedance nodes short and shielded

Consider filtering (RC, active) to limit bandwidth to signal range

Use metal film resistors for low noise

Implement proper thermal design to avoid thermocouple effects.

Start with low-noise components and proper layout. Add filtering only if necessary to preserve bandwidth.

Voltage reference selection affects ADC accuracy: Initial accuracy - choose better than your ADC LSB (0.05% for 12-bit, 0.01% for 16-bit)

Temperature coefficient - critical for wide temperature range (choose <50ppm/°C for 12-bit, <10ppm/°C for 16-bit)

Long-term drift - important for calibration stability

Output current - ensure reference can drive ADC reference input

Noise - broadband noise affects ADC SNR. ST's TL series offers precision references suitable for most applications.

Match reference accuracy to your ADC resolution and temperature range requirements.

LDO selection criteria include: Dropout voltage - must be less than Vin(min) - Vout at full load

Output current - rated at least 20% above maximum load

Quiescent current - critical for battery life (choose <10uA for always-on supplies)

PSRR - important for noise-sensitive analog circuits (choose >60dB at 1kHz)

Noise - specify for sensitive applications

Thermal design - verify power dissipation (Pd = (Vin-Vout) × Iout) is within limits. ST's LD39100 and LDL series offer excellent options.

Calculate worst-case power dissipation first. Select LDO with adequate thermal margin.