Datasheet

Data Sheet ADP124/ADP125
Rev. C | Page 9 of 20
–100
–90
–80
–70
–60
–50
–40
–30
–20
–10
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
PSRR (dB)
I
OUT
= 100µA
V
IN
= V
OUT
+ 1V
V
RIPPLE
= 50mV
C
IN
= C
OUT
= 1µF
I
OUT
= 1mA
I
OUT
= 10mA
I
OUT
= 100mA
I
OUT
= 300mA
I
OUT
= 500mA
08476-017
Figure 19. Power Supply Rejection Ratio vs. Frequency, V
OUT
= 4.2 V, V
IN
= 5.2 V
–100
–90
–80
–70
–60
–50
–40
–30
–20
–10
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
PSRR (dB)
V
OUT
= 2.8V, I
OUT
= 10mA
V
IN
= V
OUT
+ 1V
V
RIPPLE
= 50mV
C
IN
= C
OUT
= 1µF
V
OUT
= 3.3V, I
OUT
= 10mA
V
OUT
= 4.2V, I
OUT
= 10mA
V
OUT
= 2.8V, I
OUT
= 500mA
V
OUT
= 3.3V, I
OUT
= 500mA
V
OUT
= 4.2V, I
OUT
= 500mA
08476-018
Figure 20. Power Supply Rejection Ratio vs. Frequency,
Various Output Voltages and Load Currents
–100
–90
–80
–70
–60
–50
–40
–30
–20
–10
10 100 1k 10k 100k 1M 10M
PSRR (dB)
FREQUENCY (Hz)
V
IN
= 3.1V, I
OUT
= 10mA
V
IN
= 3.3V, I
OUT
= 10mA
V
IN
= 3.8V, I
OUT
= 10mA
V
IN
= 4.8V, I
OUT
= 10mA
V
IN
= 3.1V, I
OUT
= 500mA
V
IN
= 3.3V, I
OUT
= 500mA
V
IN
= 3.8V, I
OUT
= 500mA
V
IN
= 4.8V, I
OUT
= 500mA
08476-019
Figure 21. Power Supply Rejection Ratio vs. Headroom Voltage (V
IN
− V
OUT
),
V
OUT
= 2.8 V
0
1
2
3
4
5
10 100 1k 10k 100k
FREQUENCY (Hz)
NOISE (µv/√Hz)
08476-020
V
OUT
= 2.8V
V
OUT
= 3.3V
V
OUT
= 4.2V
Figure 22. Output Noise Spectrum, V
IN
= 5 V
20
25
30
35
40
45
50
55
60
65
70
0.001 0.01 0.1 1 10 100 1k
I
LOAD
(mA)
RMS NOISE (µV)
V
OUT
= 2.8V
V
OUT
= 3.3V
V
OUT
= 4.2V
08476-021
Figure 23. Output Noise vs. Load Current and Output Voltage, V
IN
= 5 V
08476-022
M40.0µs A CH1 200mA
1
2
T 9.800%
V
IN
= 4V
V
OUT
= 3.3V
V
OUT
1mA TO 500mA LOAD STEP
CH1 500mA Ω
B
W
CH2 50.0mV
B
W
I
OUT
Figure 24. Load Transient Response, C
OUT
= 1 μF