ADP7185ACPZN3.3-R7

Overview

The ADP7185ACPZN3.3-R7 is a negative-output low dropout linear regulator manufactured by Analog Devices Inc., housed in an 8-lead, 2 mm × 2 mm LFCSP package. It delivers a fixed output voltage of −3.3 V with a maximum load current capability of −500 mA. The device operates from an input voltage range of −2.0 V to −5.5 V and features ultralow noise performance, specified at 4 μV rms from 100 Hz to 100 kHz. It provides high power supply rejection ratio (PSRR), reaching 68 dB at 10 kHz under full load conditions. The regulator includes positive or negative enable logic, current-limit protection, and thermal overload shutdown.

Feature Summary

• Ultralow noise architecture providing stable regulation for sensitive analog circuits
• High power supply rejection ratio effective across a wide frequency spectrum
• Flexible enable logic compatible with both positive and negative control signals
• Integrated current-limit and thermal overload protection mechanisms

Applications

• Powering analog-to-digital converters requiring clean negative rails
• Supplying precision amplifiers in instrumentation systems
• Biasing digital-to-analog converters in communication infrastructure
• Providing regulated power for medical and healthcare equipment

Procurement Notes

Verify the specific suffix R7 indicates reel packaging when sourcing. Confirm the ACPZN variant matches the required 8-lead LFCSP footprint. Ensure the 3.3 designation aligns with system voltage requirements. Check manufacturer documentation for RoHS compliance status. Validate lead times directly with authorized distributors as availability fluctuates.

Selection Notes

Select this component when a negative rail is required for mixed-signal applications. The fixed −3.3 V output eliminates external feedback resistors, simplifying design. Ensure input voltage remains within the −2.0 V to −5.5 V operational window. Verify that the 4.7 μF ceramic capacitor requirement fits the board space constraints. Consider the thermal resistance characteristics if operating near maximum load currents.

Part Context

This part belongs to the ADP7185 family of low dropout regulators designed for high-performance analog applications. The series offers various fixed output voltages ranging from −0.5 V to −4.5 V. All variants share the same compact LFCSP package and core architectural benefits, including ultralow noise and high PSRR. The family supports both fixed and adjustable output configurations to accommodate diverse system needs.

Replacement Considerations

Direct substitutes include other ADP7185 variants with different fixed output voltages such as ADP7185ACPZN2.5-R7 or ADP7185ACPZN1.2-R7. Cross-family replacements require verification of pin compatibility and electrical specifications. Ensure any alternative maintains the required −500 mA current capability and negative polarity.