HGSEMI Power Management ICs

Choose an LDO when: The input-output voltage difference is small (low dropout)

Low noise is critical for sensitive analog circuits

Simple design and low cost are priorities

and The application has low current requirements. Choose a switching regulator when: High efficiency is required (especially for battery-powered devices)

Large input-output voltage difference exists

High output current is needed

and Heat dissipation is a concern. LDOs are simpler but less efficient, while switching regulators are more efficient but more complex with higher noise.

For battery applications where efficiency matters, use switching regulators. For analog circuits requiring clean power, use LDOs. Contact our FAE team for topology recommendations.

Dropout voltage is the minimum input-to-output voltage differential required for an LDO to maintain regulation. When the input voltage approaches the output voltage plus dropout voltage, the LDO enters dropout mode where it can no longer regulate properly. For example, a 3.3V LDO with 200mV dropout requires minimum 3.5V input. Low-dropout (LDO) regulators have dropout voltages from 50mV to 500mV, while standard linear regulators may require 2-3V headroom. When selecting an LDO, ensure Vin(min) > Vout + Vdropout(max) under all operating conditions including battery discharge.

Calculate worst-case input voltage including battery discharge and load transients. Select LDO with adequate dropout margin. Our FAE team can help with LDO selection.

Power dissipation in a linear regulator is calculated as Pd = (Vin - Vout) × Iout + Vin × Iq, where Vin is input voltage, Vout is output voltage, Iout is output current, and Iq is quiescent current. The dominant term is (Vin - Vout) × Iout. For example, with 5V input, 3.3V output, and 100mA load: Pd = (5 - 3.3) × 0.1 = 0.17W. At 500mA load, Pd = 0.85W, requiring thermal management. Efficiency is Vout/Vin, so 3.3V/5V = 66% in this example. Higher input-output differential or higher current increases dissipation significantly.

Calculate dissipation at maximum load and minimum input voltage. Ensure package can handle power with adequate margin. Contact our FAE team for thermal analysis.

PSRR (Power Supply Rejection Ratio) measures how well a regulator rejects noise and ripple from the input power supply. It's expressed in dB, with higher values indicating better rejection. For example, 60dB PSRR means input ripple is attenuated by 1000x (60dB = 20×log10(1000)). PSRR is frequency-dependent, typically highest at low frequencies and decreasing at higher frequencies. High PSRR is critical for analog circuits (ADCs, DACs, op-amps) and RF circuits where power supply noise affects performance. Audio applications also benefit from high PSRR to prevent audible hum.

For noise-sensitive applications, select LDOs with PSRR > 60dB at relevant frequencies. Our FAE team can recommend high-PSRR regulators for your application.

HGSEMI power management ICs include comprehensive protection features: Over-current protection (OCP) limits output current during short circuits or overloads

Over-temperature protection (OTP) shuts down the device if junction temperature exceeds safe limits

Under-voltage lockout (UVLO) prevents operation when input voltage is too low for proper regulation

Soft-start limits inrush current during startup

and Reverse current protection prevents damage from output voltage exceeding input voltage. These protections ensure reliable operation and prevent damage to the IC and system under fault conditions.

For robust designs, ensure all relevant protection features are included. Contact our FAE team for protection feature recommendations for your application.