1MHz Step-Down Converter/LDO Regulator
Typical Characteristics
Unless otherwise noted, V
IN
= 5V, T
A
= 25°C, V
IN
= V
LDO
= V
CC
= V
P
.
AAT2500
LDO Turn-Off Response Time
(C
BYP
= 10nF; EN = GND; ENLDO = V
IN
)
LDO Turn-On Time From Enable (V
IN
present)
(C
BYP
= 10nF; EN = GND; ENLDO = V
IN
)
V
ENLDO
= 5V/div
V
ENLDO
(5V/div)
V
OUT
(1V/div)
50μs/div
V
OUT
= 1V/div
μ
5μs/div
V
IN
= 4V
LDO Line Transient Response
(C
BYP
= 10nF; EN = GND; ENLDO = V
IN
)
6
5
3.04
LDO Load Transient Response
(C
BYP
= 10nF; EN = GND; ENLDO = V
IN
)
2.90
2.85
2.80
2.75
2.70
2.65
2.60
500
Input Voltage (V)
V
IN
Output Voltage (V)
3.03
3.02
3.01
3.00
V
OUT
400
300
200
100
0
-100
Output Current (mA)
Output Voltage (V)
4
3
2
1
0
V
OUT
2.99
2.98
I
OUT
100μS/div
100μs/div
LDO Load Transient Response 300mA
(C
BYP
= 10nF; EN = GND; ENLDO = V
IN
)
2.90
700
LDO Self Noise
(EN = GND; ENLDO = V
IN
)
2.80
2.70
2.60
2.50
2.40
2.30
2.20
2.10
V
OUT
600
500
400
300
200
Noise Amplitude (μV/rtHz)
3.00
800
10
Output Current (mA)
Output Voltage (V)
1
0.1
0.01
I
OUT
100
0
-100
Band Power:
300Hz to 50kHz = 44.6μVrms
100Hz to 100kHz = 56.3μVrms
0.1
1
10
100
1000
10000
0.001
0.01
10μs/div
μ
Frequency (kHz)
2500.2006.05.1.16
7
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
