AAT1150_06 Datasheet, PDF (10/17 Pages) Advanced Analogic Technologies – 1MHz 1A Step-Down DC/DC Converter

AAT1150
1MHz 1A Step-Down DC/DC Converter
Power and Signal Source
Separate small signal ground and power supply
pins isolate the internal control circuitry from the
noise associated with the output MOSFET switch-
ing. The low pass filter R1 and C3 in schematic
Figures 1 and 2 filters the noise associated with the
power switching.
Current Limit and Over-Temperature
Protection
For overload conditions, the peak input current is lim-
ited. Figure 3 displays the current limit characteris-
tics. As load impedance decreases and the output
voltage falls closer to zero, more power is dissipated
internally, raising the device temperature. Thermal
protection completely disables switching when inter-
nal dissipation becomes excessive, protecting the
device from damage. The junction over-temperature
threshold is 140°C with 15°C of hysteresis.
2.7V-5.5V
C1
10μF
R1 100
R2
100k
C7
0.1μF
AAT1150-1.5
VP
FB
VCC
LX
EN
LX
SGND PGND
VOUT 1.5V 1A
L1
4.1μH
C2, C3, C4
3x 22μF
6.3V
RTN
C1 Murata 10μF 6.3V X5R GRM42-6X 5R106K6.3
C2, C3, C4 MuRata 22μF 6.3V GRM21BR60J226ME39L 0805 X5R
L1 Sumida CDRH5D18-4R1μH
100
80
60
40
20
0
10
Efficiency vs. Output Current
(V_OUT = 1.5V)
2.7V
4.2V
3.6V
100
1000
Output Current (mA)
Figure 1: Lithium-Ion to 1.5V Converter.
3.5V-5.5V
C1
10μF
R1 100
R2
100k
C7
0.1μF
AAT1150-3.3
VP
FB
VCC
LX
EN
LX
SGND PGND
VOUT 3.3V 1A
L1
4.1μH
C2, C3, C4
3x 22μF
6.3V
RTN
C1 Murata 10μF 6.3V X5R GRM42-6X 5R106K6.3
C2, C3, C4 MuRata 22μF 6.3V GRM21BR60J226ME39L X5R 0805
L1 Sumida CDRH5D18-4R1μH
Efficiency vs. Output Current
(V_OUT = 3.3V)
100
90 _{VIN = 5.0V}
80
70
60
50
40
30
20
10
0
10
100
1000
Output Current (mA)
Figure 2: 5V Input to 3.3V Output Converter.
10
1150.2006.09.1.5