GENERAL DESCRIPTION

The ADM7171 is a CMOS, low dropout linear regulator (LDO) that operates from 2.3 V to 6.5 V and provides up to 1 A of output current. This high output current LDO is ideal for regulation of high performance analog and mixed signal circuits operating from 6 V down to 1.2 V rails. Using an advanced proprietary architecture, the device provides high power supply rejection and low noise, and achieves excellent line and load transient response with just a small 4.7 μF ceramic output capacitor. Load transient response is typically 1.5 μs for a 1 mA to 500 mA load step.

The ADM7171 is available in 17 fixed output voltage options. The following voltages are available from stock: 1.3 V, 1.8 V, 2.5 V, 3.0 V, 3.3 V, 4.2 V, and 5.0 V. Additional voltages that are available by special order are: 1.5 V, 1.85 V, 2.0 V, 2.2 V, 2.7 V, 2.75 V, 2.8 V, 2.85 V, 3.8 V, and 4.6 V. An adjustable version is also available that allows output voltages that range from 1.2 V to VIN − VDO with an external feedback divider.

Inrush current can be controlled by adjusting the start-up time via the soft start pin. The typical start-up time with a 1 nF soft start capacitor is 1.0 ms.

The ADM7171 regulator output noise is 5 μV rms independent of the output voltage. The ADM7171 is available in an 8-lead, 3 mm × 3 mm LFCSP, making it not only a very compact solution, but also providing excellent thermal performance for applications requiring up to 1 A of output current in a small, low profile footprint.

FEATURES

Input voltage range: 2.3 V to 6.5 V

Maximum load current: 1 A

Low noise: 5 μV rms independent of output voltage at

100 Hz to 100 kHz

Fast transient response: 1.5 μs for 1 mA to 500 mA load step

60 dB PSRR at 100 kHz

Low dropout voltage: 42 mV at 500 mA load, VOUT = 3 V

Initial accuracy: −0.5 (minimum), +1 (maximum)

Accuracy over line, load, and temperature: ±1.5

Quiescent current, IGND = 0.7 mA with no load

Low shutdown current: 0.25 μA at VIN = 5 V

Stable with small 4.7 μF ceramic output capacitor

Adjustable and fixed output voltage options: 1.2 V to 5.0 V

Adjustable output from 1.2 V to VIN − VDO

Precision enable

Adjustable soft start

8-lead, 3 mm × 3 mm LFCSP package

Supported by ADIsimPower tool

APPLICATIONS

Regulation to noise sensitive applications: ADC and DAC

circuits, precision amplifiers, PLLs/VCOs, and clocking ICs

Communications and infrastructure

Medical and healthcare

Industrial and instrumentation