The ADP7105 is a CMOS, low dropout (LDO) linear regulator that operates from 3.3 V to 20 V and provides up to 500 mA of output current. This high input voltage LDO is ideal for regula-tion of high performance analog and mixed-signal circuits operating from 1.22 V to 19 V rails. Using an advanced proprietary architecture, the ADP7105 provides high power supply rejection and low noise, and achieves excellent line and load transient response with only a small 1 μF ceramic output capacitor.
The ADP7105 is available in three fixed output voltage options and an adjustable version that allows output voltages ranging from 1.22 V to 19 V via an external feedback divider. The ADP7105 allows an external soft start capacitor to be connected to program the startup.
Note that throughout this data sheet, the sense function (SENSE) of the SENSE/ADJ pin applies to fixed output voltage models only, whereas the adjust input function (ADJ) applies to adjustable output voltage models only. For example, Figure 1 shows the sense function, and Figure 2 shows the adjust input function.
The ADP7105 output noise voltage is 15 μV rms and is inde-pendent of the output voltage. A digital power-good output allows power system monitors to check the health of the output voltage. A user programmable precision undervoltage lockout function facilitates sequencing of multiple power supplies.
The ADP7105 is available in 8-lead, 3 mm × 3 mm LFCSP and 8-lead SOIC packages. The LFCSP offers a very compact solution and provides excellent thermal performance for applications that require up to 500 mA of output current in a small, low profile footprint.
**APPLICATIONS**
Regulation of noise sensitive applications:
ADC and DAC circuits, precision amplifiers,
high frequency oscillators, clocks, and PLLs
Communications and infrastructure
Medical and healthcare
Industrial and instrumentation
### Features and Benefits
Input voltage range: 3.3 V to 20 V
Maximum output current: 500 mA
Low noise: 15 μV rms for fixed output versions
PSRR performance of 60 dB at
10 kHz, VOUT = 3.3 V
Reverse current protection
Low dropout voltage: 350 mV at
500 mA
Initial accuracy: ±0.8%
Accuracy over line, load, and temperature: −2% to +1%
Low quiescent current: 900 μA at
VIN = 10 V, IOUT = 500 mA
Low shutdown current: <50 μA at
VIN = 12 V, stable with small 1 μF ceramic output capacitor
