ADM7171ACPZ-4.2-R7

Overview

The ADM7171ACPZ-4.2-R7 is a CMOS low dropout linear regulator manufactured by Analog Devices Inc., operating from an input voltage range of 2.3 V to 6.5 V and providing up to 1 A of output current. This specific variant features a fixed output voltage of 4.2 V with an initial accuracy of −0.5% to +1%. It delivers ultralow noise performance, typically 5 μV rms in the 100 Hz to 100 kHz bandwidth, and achieves high power supply rejection ratio (PSRR) of 60 dB at 100 kHz. The device ensures fast transient response, settling within 1.5 μs for a 1 mA to 500 mA load step. It incorporates precision enable control, adjustable soft start capabilities, and comprehensive protection against overcurrent and thermal overload.

Feature Summary

• Ultralow noise architecture delivering consistent 5 μV rms output noise independent of the set output voltage.
• High power supply rejection ratio maintaining 60 dB attenuation at 100 kHz for effective ripple suppression.
• Fast transient response capability achieving 1.5 μs recovery time during significant load current steps.
• Precision enable pin with defined logic thresholds allowing precise digital control of regulator activation.

Applications

• Regulation for noise-sensitive analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits
• Powering precision amplifiers requiring stable low-noise supply rails
• Supplying phase-locked loops (PLLs) and voltage-controlled oscillators (VCOs)
• Clocking integrated circuits demanding minimal jitter and noise interference

Procurement Notes

Verify the exact part number ADM7171ACPZ-4.2-R7 against official Analog Devices documentation to confirm the fixed 4.2 V output specification. Ensure compatibility with the required 8-lead LFCSP package dimensions and thermal requirements. Confirm RoHS compliance status and moisture sensitivity level prior to integration into manufacturing processes.

Selection Notes

Select this component when designing systems requiring a fixed 4.2 V rail with stringent noise and transient response specifications. Evaluate the input voltage headroom to ensure it remains above the minimum dropout threshold under maximum load conditions. Consider the thermal resistance characteristics of the PCB layout to manage junction temperature effectively during operation.

Part Context

This device belongs to the ADM7171 family of high-performance CMOS LDO regulators designed for portable and battery-powered applications. The series offers various fixed output voltages alongside an adjustable version, all sharing common architectural benefits such as ultralow noise and high PSRR. It complements other power management solutions like the ADM7170 and ADM7172, which provide different current capabilities within the same voltage range.

Replacement Considerations

Direct substitutes include other fixed-output variants within the ADM7171 family, such as the ADM7171ACPZ-3.0-R7 or ADM7171ACPZ-5.0-R7, provided the specific voltage requirement differs. For higher current needs, the ADM7172 series may be considered, though pinout and thermal characteristics must be verified.