EMBEDDED TOOLKIT

SYSTEMS R&D // DEV_TOOLS SUITE

Tools (65)

> Clock & USB Calculator > Timer & PWM Calculator > ADC Calculator > Communication Timings (UART/SPI/I2C/CAN) > Memory Map Visualizer > CubeMX Utilities

adc calculator

SYSTEM ONLINE

ADC Parameters

ADC Clock [MHz]

Usually derived from APB2 after an additional prescaler (e.g., /2, /4)

Resolution (Bits)

Sampling Time [Cycles]

Conversion Time

Total Time (Cycles)

27 ADC cycles

Sampling (15) + Conversion (12)

Physical Time for 1 Measurement

0.750 µs

(750 ns)

Continuous Sampling Frequency

1333.3 kHz

When Continuous mode or Free-Running Timer is enabled

📖 STM32 ADC Timing Calculator

The physical time to read voltage by the ADC is crucial, e.g., when reading audio signals, motor control (FOC), or just fast channel switching (Scan Mode).

Total time consists of the Sampling phase (charging the microcontroller input capacitor) and SAR Conversion (directly dependent on resolution, e.g., 12 cycles for 12-bit).
High signal source impedance (e.g., large resistor on a divider) forces a longer sampling time (e.g., 144 cycles), otherwise the reading will be distorted (the capacitor won't have time to charge). The script calculates how this affects the final time in microseconds.