pcb

Select bypass and bulk decoupling capacitors for IC power supply pins. Computes the target PDN (Power Distribution Network) impedance from supply current, voltage, and allowable ripple using Z_target = V_ripple / I_total. Recommends a ceramic bypass capacitor (high-frequency decoupling, placed closest to IC pins) and a bulk capacitor (low-frequency decoupling, near the regulator). Calculates the ceramic cap's self-resonant frequency assuming typical lead inductance, and checks whether ESR-induced ripple stays within limits. Essential for digital, analog, and mixed-signal PCB design. Chain with lc_resonance to verify the decoupling capacitor's resonant behavior, or with trace_width to size the power trace.

post/api/power_supply_decoupling

Request

  • Base URL: https://calc.engineer
  • URL: https://calc.engineer/api/power_supply_decoupling
  • Auth: none declared

Request body

supply_current_manumber required

IC supply current draw in milliamps (mA). Use the maximum or typical from the datasheet.

supply_voltage_vnumber required

Supply voltage in volts (V). Common values: 1.8, 2.5, 3.3, 5.0, 12.0.

switching_freq_mhznumber

Primary switching or clock frequency of the IC in MHz. Determines the target impedance frequency range.

max_ripple_mvnumber

Maximum allowable supply ripple in millivolts (mV). Typical: 50 mV for digital, 10 mV for analog/RF.

num_icsnumber

Number of identical ICs sharing this supply rail. Scales the total current demand.

esr_mohmnumber

Equivalent series resistance (ESR) of the ceramic bypass capacitor in milliohms. Typical MLCC: 5-20 mohm.

Response

Computed result for power_supply_decoupling

toolstring required
versionstring required
computed_atstring date-time required

Changes

No recorded changes to this operation across all 1 revision of this API.