ADP7156ACPZ-3.3-R7

Overview

The ADP7156ACPZ-3.3-R7 is a fixed-output linear regulator providing 3.3 V at up to 1.2 A load current. It operates from an input voltage range of 2.3 V to 5.5 V with a typical dropout voltage of 120 mV at full load. The device features ultralow noise, specified as 0.9 µV rms (100 Hz to 100 kHz) and 1.7 nV/√Hz spectral density (10 kHz to 1 MHz). Power supply rejection ratio reaches 80 dB from 1 kHz to 100 kHz. Quiescent current is 4.0 mA at no load and 7 mA at maximum output. Initial accuracy is ±0.6% at 25°C, expanding to ±1.5% over the -40°C to +125°C temperature range.

Feature Summary

• Ultralow noise architecture optimized for radio frequency applications
• High power supply rejection ratio across wide frequency bands
• Precision enable pin with defined logic thresholds and hysteresis
• Stable operation with standard ceramic output capacitors

Applications

• Phase-locked loops (PLLs)
• Voltage controlled oscillators (VCOs)
• Backhaul and microwave links

Procurement Notes

Verify package integrity upon receipt, as the LFCSP is ESD sensitive. Confirm that input and output capacitors meet minimum capacitance and ESR requirements to ensure stability. Check PCB layout against thermal guidelines to maintain junction temperature within operational limits under maximum load conditions.

Selection Notes

Select this component when ultra-low phase noise is critical for RF signal integrity. Ensure the input voltage remains above the minimum operating threshold while accounting for dropout voltage at peak load currents. Verify that the available 10 µF ceramic output capacitor meets the specific ESR constraints required for loop stability.

Part Context

This part belongs to the ADP7156 family of high-performance linear regulators designed for demanding RF environments. It shares architectural similarities with the ADP7157 and ADP7158 but offers fixed voltage options. The device utilizes a proprietary P-channel MOSFET pass transistor controlled by a heavily filtered error amplifier to minimize noise injection.

Replacement Considerations

ADP7157ACPZ-3.3-R7

FAQ

How does the BYP capacitor affect output noise performance?

Increasing the BYP capacitor value reduces output noise below 1 kHz. While a 1 µF ceramic capacitor is standard, larger tantalum capacitors can be used for lower noise, provided a ceramic capacitor is paralleled for high-frequency performance.

What is the function of the VOUT_SENSE pin?

The VOUT_SENSE pin allows for remote sensing of the output voltage. It is internally connected to VOUT via a 10 Ω resistor and should be connected close to the load to compensate for trace resistance drops.