6.5 V, 2 A, Ultralow Noise, High PSRR, Fast
Transient Response CMOS LDO
ADM7172
Data Sheet
FEATURES
TYPICAL APPLICATION CIRCUIT
Input voltage range: 2.3 V to 6.5 V
Maximum load current: 2 A
Low noise: 5 μV rms independent of output voltage at
100 Hz to 100 kHz
ADM7172
V
= 5V
V
= 3.3V
IN
OUT
VIN
VOUT
C
C
OUT
4.7µF
IN
VIN
VOUT
4.7µF
SENSE
ON
Fast transient response: 1.5 ꢀs for 1 mA to 1.5 A load step
60 dB PSRR at 100 kHz
EN
SS
C
1nF
SS
OFF
GND
Low dropout voltage: 172 mV at 2 A 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 ꢀA 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
Figure 1. ADM7172 with Fixed Output Voltage, 3.3 V
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 ADM7172 regulator output noise is 5 ꢀV rms, independent
of the output voltage. The ADM7172 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 2 A of output current in a small, low profile
footprint.
Adjustable soft start
8-lead 3 mm × 3 mm LFCSP package
Supported by ADIsimPower™ tool
APPLICATIONS
T
Regulation to noise sensitive applications: ADC and DAC
circuits, precision amplifiers, PLLs/VCOs, and clocking ICs
Communications and infrastructure
1
Medical and healthcare
Industrial and instrumentation
GENERAL DESCRIPTION
2
The ADM7172 is a CMOS, low dropout linear regulator (LDO)
that operates from 2.3 V to 6.5 V and provides up to 2 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 ꢀs for a 1 mA to 1.5 A load step.
B
B
CH1 1.0A Ω
CH2 20mV
M400ns A CH3
T 0.0%
100mV
W
W
Figure 2. Transient Response (Trace 2), 1 mA to 1.5 A Load Step in 400 ns (Trace 1)
Table 1. Related Devices
Device
Input Voltage
Output Current
500 mA
1 A
Package
The ADM7172 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.
ADM7170 2.3 V to 6.5 V
ADM7171 2.3 V to 6.5 V
8-lead LFCSP
8-lead LFCSP
Rev. C
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