ADP7185ACPZN1.5-R7

Overview

The ADP7185ACPZN1.5-R7 is a negative low dropout linear regulator from Analog Devices, providing a fixed output voltage of -1.5 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 filtering across frequencies up to 1 MHz under heavy load conditions.
• Flexible enable pin supports both positive and negative logic levels to interface seamlessly with various system controllers.
• Stable operation achieved using small ceramic capacitors, specifically requiring only 4.7 μF for both input and output stages.

Applications

• Power regulation for analog-to-digital converters (ADCs) requiring clean negative rails
• Supply conditioning for digital-to-analog converters (DACs) in precision instrumentation
• Biasing and regulation for precision amplifiers in medical and healthcare equipment
• Noise-sensitive circuitry in communications and infrastructure systems

Procurement Notes

Verify the specific ordering suffix R7 indicates reel packaging when sourcing components. Confirm that the ACPZN variant corresponds to the 8-lead LFCSP package type required for your board layout. Ensure compatibility with the -1.5 V fixed output specification rather than adjustable versions. Check manufacturer documentation for any recent revision updates affecting electrical characteristics or thermal performance data.

Selection Notes

Select this component when designing circuits requiring a stable negative voltage rail with minimal noise interference. The -500 mA current capability suits moderate power applications without excessive heat dissipation. Consider the 4.7 μF capacitor requirement for stability, which simplifies bill of materials compared to devices needing larger electrolytic capacitors. Evaluate the dropout voltage specifications against your minimum input voltage constraints to ensure proper regulation during transient loads.

Part Context

This regulator belongs to the ADP7185 family of complementary metal oxide semiconductor low dropout linear regulators designed for high-performance analog and mixed-signal circuits. The series provides multiple fixed output voltage options ranging from -0.5 V to -4.5 V, alongside an adjustable version. These devices share common architectural features including ultralow noise profiles and high PSRR, making them suitable for sensitive signal processing applications requiring precise negative voltage regulation.

Replacement Considerations

Direct substitutes include other ADP7185 variants with different fixed output voltages such as ADP7185ACPZN3.3-R7 or ADP7185ACPZN2.5-R7 if voltage requirements differ. Adjustable versions like ADP7185ACPZN-ADJ-R7 offer flexibility but require external feedback networks. Verify pinout compatibility and thermal resistance values when replacing with similar negative LDO regulators from other manufacturers.