ADP7185ACPZN1.8-R7

Overview

The ADP7185ACPZN1.8-R7 is a negative low dropout linear regulator from Analog Devices, providing a fixed output voltage of -1.8 V with a maximum load current of -500 mA. It operates within an input voltage range of -2.0 V to -5.5 V and features ultralow noise performance, delivering 4 μV rms integrated noise from 100 Hz to 100 kHz. The device offers high power supply rejection ratios of 68 dB at 10 kHz and 40 dB at 1 MHz under full load conditions. It utilizes an 8-lead, 2 mm × 2 mm LFCSP package and includes positive or negative enable logic for flexible system control.

Feature Summary

• Ultralow noise architecture delivers consistent 4 μV rms output noise independent of the selected output voltage setting.
• High power supply rejection ratio maintains effective noise filtering across a wide frequency spectrum up to 1 MHz.
• Flexible enable pin supports both positive and negative logic levels to interface seamlessly with various system controllers.
• Stable operation is achieved using small ceramic capacitors, specifically requiring only 4.7 μF for both input and output stages.

Applications

• Powering analog-to-digital converters (ADCs) in data acquisition systems
• Supplying precision amplifiers in industrial instrumentation
• Providing clean power rails for digital-to-analog converters (DACs)
• Regulating power in medical and healthcare equipment

Procurement Notes

Verify the specific ordering suffix matches the required output voltage configuration before procurement. Confirm that the component meets RoHS compliance standards for your region. Ensure the supplier provides valid traceability documentation. Check for any recent product change notices regarding manufacturing location updates. Validate that the package type aligns with your PCB footprint requirements.

Selection Notes

Select this regulator when designing circuits that require stable negative voltage rails for sensitive analog components. Consider the thermal resistance characteristics of the LFCSP package for high-current applications. Evaluate the startup time requirements against the capacitance values used on the feedback and reference pins. Ensure the input voltage remains within the specified operating range to maintain regulation.

Part Context

This component belongs to the ADP7185 family of low dropout linear regulators designed by Analog Devices. The series focuses on delivering high performance for noise-sensitive mixed-signal applications. Other variants in the family offer different fixed output voltages ranging from -0.5 V to -4.5 V, as well as adjustable versions. All share the same compact package and core architectural benefits.

Replacement Considerations

Direct replacements include other ADP7185 variants with different fixed output voltages such as ADP7185ACPZN3.3-R7 or ADP7185ACPZN2.5-R7. Verify that substitute parts maintain the same -500 mA current capability and package dimensions. Ensure compatibility with existing PCB layouts and thermal management strategies.