LD6935L/3318PX

Overview

The LD6935L/3318PX is a dual Low Dropout (LDO) regulator from NXP Semiconductors, housed in an 8-terminal DFN1612-8 (SOT1225) leadless package measuring 1.6 x 1.2 x 0.4 mm. It provides two independent fixed output voltages: OUT1 at 3.3 V and OUT2 at 1.8 V. Each LDO channel delivers up to 300 mA with a typical dropout voltage of 240 mV at full load. The input voltage range spans from 1.75 V to 5.5 V. Key electrical characteristics include a power supply rejection ratio (PSRR) of 80 dB at 1 kHz and an RMS output noise of 60 µV over the 10 Hz to 100 kHz bandwidth. The device features integrated soft-start functionality, low quiescent current, and auto-discharge capabilities for rapid output voltage decay upon shutdown.

Feature Summary

• Dual independent LDO channels providing separate 3.3 V and 1.8 V outputs within a compact footprint
• Integrated auto-discharge circuitry ensures rapid output voltage decay when disabled
• Soft-start control manages inrush current during startup to protect system components
• High PSRR and low output noise support sensitive analog and digital loads

Applications

• Smartphones and mobile handsets
• Tablet PCs and portable media players
• Mobile internet devices and digital still cameras

Procurement Notes

Verify the specific suffix 'P' indicates pull-down output mode rather than high-ohmic state. Confirm the package orientation matches the Q1 quadrant specification for DFN1612-8. Ensure external capacitors meet the minimum 0.7 µF requirement with appropriate ESR ranges for stability. Check that the application environment stays within the -40 °C to +85 °C operating temperature limits.

Selection Notes

Select this component when space-constrained designs require dual regulated rails from a single package. The 3.3 V and 1.8 V combination suits systems needing core logic and peripheral power. Consider the auto-discharge feature if fast shutdown times are critical. Verify that the input voltage remains above the nominal output plus dropout requirements across all load conditions.

Part Context

The LD6935 series comprises small-size dual LDO regulators designed for portable electronics. This family offers various output voltage combinations and enable pin configurations. The LD6935L/3318PX specifically targets applications requiring simultaneous 3.3 V and 1.8 V supplies with minimal board space usage.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.