PRODUCT DATASHEET
AAT2789
SystemPower
TM
Low Noise, High Frequency Dual Step-Down Converter
Typical Characteristics – Channel 1
Line Transient Response
(V
OUT
= 1.8V; I
OUT
= 1.5A; C
FF
= 100pF)
5.0
4.5
0.12
0.10
0.08
0.06
0.04
0.02
0.00
-0.02
-0.04
0.40
0.30
Line Regulation
(V
OUT
= 1.8V; I
OUT
= 1A)
Output Voltage (AC coupled)
(bottom) (V)
V
OUT
Error (%)
Input Voltage
(top) (V)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.20
0.10
0.00
-0.10
-0.20
-0.30
-0.40
2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5
Time (100µs/div)
Input Voltage (V)
Light Load Switching Waveform
(V
IN
= 3.6V; V
OUT
= 1.8V; I
OUT
= 1mA; C
FF
= 0pF)
Output Voltage (AC coupled)
(top)(mV)
Output Voltage (AC coupled)
(top)(mV)
80
40
0
-40
-80
-120
-160
-200
-240
0.7
80
40
0
-40
-80
-120
-160
-200
-240
Light Load Switching Waveform
(V
IN
= 3.6V; V
OUT
= 1.8V; I
OUT
= 1mA; C
FF
= 0pF)
0.7
Inductor Ripple Current
(bottom) (A)
Inductor Ripple Current
(bottom) (A)
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
Time (5µs/div)
Time (200µs/div)
Light Load Switching Waveform
(V
IN
= 3.6V; V
OUT
= 1.8V; I
OUT
= 1mA; C
FF
= 100pF)
Output Voltage (AC coupled)
(top)(mV)
80
40
0
-40
-80
-120
-160
-200
-240
0.7
Light Load Switching Waveform
(V
IN
= 3.6V; V
OUT
= 1.8V; I
OUT
= 1mA; C
FF
= 100pF)
Output Voltage (AC coupled)
(top)(mV)
80
40
0
-40
-80
-120
-160
-200
-240
0.7
Inductor Ripple Current
(bottom) (A)
Inductor Ripple Current
(bottom) (A)
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
Time (5µs/div)
Time (500µs/div)
2789.2008.03.1.0
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