ANALOGICTECH AAT1152_06

AAT1152
850kHz 1A Buck DC/DC Converter
General Description
Features
The AAT1152 SwitchReg is a step-down switching
converter ideal for applications where high efficiency, small size, and low ripple are critical. Able to
deliver 1A with internal power MOSFETs, the current mode controlled IC is internally compensated
for simplified system design and low external parts
count.
•
•
•
•
•
•
•
•
•
•
The AAT1152 features a Power-OK (POK) function
which monitors the output, alerting the system if
the output voltage falls out of regulation.
The AAT1152 is available in a Pb-free MSOP-8
package and is rated over the -40°C to +85°C temperature range.
•
•
•
•
•
•
SwitchReg™
5.5V Max Supply Input
Fixed or Adjustable VOUT 1.0V to 4.2V
1A Output Current
Integrated Low On Resistance Power Switches
Up to 95% Efficiency
Power-OK Signal
Internally Compensated Current Mode Control
High Initial Accuracy: ±1%
850kHz Switching Frequency
Constant Pulse Width Modulation (PWM)
Mode
Low Output Ripple with Light Load
Internal Soft Start
Current Limit Protection
Over-Temperature Protection
MSOP-8 Package
-40°C to +85°C Temperature Range
Applications
•
•
•
•
•
Cable/DSL Modems
Computer Peripherals
High Efficiency Conversion from 5V or 3.3V
Supply
Network Cards
Set-Top Boxes
Typical Application
INPUT
100k
VP
10μF
AAT1152
FB
POK
4.1μH
LX
ENABLE
100Ω
VCC
SGND
PGND
3 x 22μF
OUTPUT
0.1μF
1152.2006.09.1.7
1
AAT1152
850kHz 1A Buck DC/DC Converter
Pin Descriptions
Pin #
Symbol
Function
1
FB
2
SGND
3
EN
4
VCC
5
VP
Input supply for converter power stage.
6
LX
Inductor connection pin.
7
POK
8
PGND
Feedback input pin.
Signal ground.
Converter enable pin.
Small signal filtered bias supply.
Power-OK indicator. Open-drain output is low when VOUT falls out
of regulation.
Power ground return for output stage.
Pin Configuration
MSOP-8
PGND
7
POK
3
6
LX
4
5
VP
SGND
2
EN
VCC
2
1
1
2
8
FB
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
Absolute Maximum Ratings1
TA = 25°C, unless otherwise noted.
Symbol
Description
VCC, VP
VLX
VFB
VEN, VPOK
TJ
TLEAD
VESD
VCC, VP to GND
LX to GND
FB to GND
POK, EN to GND
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads, 10 sec)
ESD Rating2 - HBM
Value
Units
6
-0.3 to VP + 0.3
-0.3 to VCC + 0.3
-0.3 to 6
-40 to 150
300
3000
V
V
V
V
°C
°C
V
Value
Units
150
833
°C/W
mW
Rating
Units
-40 to +85
°C
Thermal Characteristics3
Symbol
ΘJA
PD
Description
Maximum Thermal Resistance (MSOP-8)
Maximum Power Dissipation (MSOP-8)
Recommended Operating Conditions
Symbol
T
Description
Ambient Temperature Range
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
3. Mounted on a demo board.
1152.2006.09.1.7
3
AAT1152
850kHz 1A Buck DC/DC Converter
Electrical Characteristics
VIN = VCC = VP = 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C.
Symbol
VIN
VOUT
ILIM
IQ
ΔVOUT (VOUT*ΔVIN)
ΔVOUT/VOUT
FOSC
RDSON(H)
RDSON(L)
VEN(H)
VEN(L)
IEN
VUVLO
VUVLO(hys)
TSD
THYS
ISHDN
VTH(POK)
RPOK
4
Description
Conditions
Min
Operation Voltage
TA = 25°C
Full Temp
DC Output Voltage Tolerance
IOUT = 500mA
Current Limit
Quiescent Supply Current
Load Regulation
Line Regulation
Oscillator Frequency
High-Side Switch On Resistance
Low-Side Switch On Resistance
Enable Input High Voltage
Enable Input Low Voltage
Enable Pin Leakage Current
TA = 25°C
No Load, VFB = 0
VIN = 4.2V, ILOAD = 0 to 1A
VIN = 2.7V to 5.5V
TA = 25°C
TA = 25°C
TA = 25°C
VIN = 2.7V to 5.5V
VIN = 2.7V to 5.5V
VEN = 5.5V
VIN Rising
VIN Falling
Under-Voltage Lockout
Under-Voltage Lockout Hysteresis
Over-Temperature Shutdown
Threshold
Over-Temperature Shutdown
Hysteresis
Shutdown Current
VEN = 0, VIN = 5.5V
VFB Ramping Up
Power-OK Threshold
VFB Ramping Down
Power-OK Pull-Down
On Resistance
Typ
2.7
-1.0
-2.0
1.2
700
160
3
0.2
850
110
100
Max
Units
5.5
1.0
2.0
V
300
1000
150
150
1.4
0.6
1
2.5
1.2
%
A
μA
%
%/V
kHz
mΩ
mΩ
V
V
μA
V
250
140
mV
°C
15
°C
1
90
88
4
μA
% of
VFB
Ω
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
Typical Characteristics
Efficiency vs. Output Current
High Side RDS(ON) vs. Temperature
(VOUT = 1.5V)
170
100
2.7V
3.6V
150
2.7V
RDS(ON) (mΩ)
Efficiency (%)
80
60
4.2V
40
3.6V
130
110
70
-20
0
10
100
1000
0
20
40
60
80
100
120
Temperature (°C)
Output Current (mA)
Low Side RDS(ON) vs. Temperature
RDS(ON) vs. Input Voltage
130
170
120
130
RDS(ON) (mΩ)
150
RDS(ON) (mΩ)
5.5V
4.2V
90
20
3.6V
2.7V
110
5.5V
90
100
Low Side
90
4.2V
70
-20
High Side
110
80
2.5
0
20
40
60
80
100
3
3.5
120
4
4.5
5
5.5
Input Voltage (V)
Temperature (°C)
Enable Threshold vs. Input Voltage
Oscillator Frequency Variation vs.
Supply Voltage
1.2
2.5
VEN(H)
Variation (%)
Enable Threshold (V)
3.5
1.1
1
0.9
VEN(L)
0.8
1.5
0.5
-0.5
-1.5
0.7
2.5
3
3.5
4
4.5
Input Voltage (V)
1152.2006.09.1.7
5
5.5
2.5
3
3.5
4
4.5
5
5.5
Supply Voltage (V)
5
AAT1152
850kHz 1A Buck DC/DC Converter
Typical Characteristics
Oscillator Frequency Variation vs. Temperature
Output Voltage vs. Temperature
(VIN = 3.6V)
(IOUT = 900mA; VOUT = 1.5V)
Output Voltage Error (%)
10
Variation (%)
6
2
-2
-6
-10
-20
0
20
40
60
80
1.0
0.6
VIN = 2.7V
0.2
-0.2
VIN = 3.6V
-0.6
-1.0
-20
100
0
20
Temperature (°C)
Line Regulation
60
80
100
Load Regulation
(VOUT = 1.5V; VIN = 3.6V)
(VOUT = 1.5V)
0.25
0
0.15
-1
IOUT = 1.0A
Error (%)
Accuracy (%)
40
Temperature (°C)
0.05
IOUT = 0.4A
-0.05
-0.15
-2
-3
-4
-0.25
2.5
3
3.5
4
4.5
5
-5
5.5
0
150
300
Input Voltage (V)
450
600
750
900
IOUT (mA)
Load Regulation
Efficiency vs. Input Voltage
(VOUT = 3.3V; VIN = 5.0V)
(VOUT = 1.5V)
0
100
-1
90
Efficiency (%)
VOUT Error (%)
IO = 1A
-2
-3
-4
IO = 0.4A
80
70
60
-5
0
150
300
450
600
750
Output Current (A)
6
900
1050
50
2.5
3
3.5
4
4.5
5
5.5
Input Voltage (V)
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
Typical Characteristics
No Load Input Current vs. Temperature
AAT1152 Loop Gain and Phase
(CO = 22μ
μF; VO = 1.5V; VIN = 3.6V; IO = 1A)
200
160
12
120
80
4
40
0
0
-4
Gain
-8
4 x 22μF
-12
-40
3 x 22μF
-80
-120
5 x 22μF
-16
-20
10
Phase (degrees)
Phase
12
-160
-200
1000
100
Input Current (mA)
20
16
8
Gain (dB)
(VCC = VP)
VCC = 5.5V
8
6
VCC = 4.2V
4
-20
-5
10
25
40
55
70
85
Temperature (°C)
Switching Waveform
(VIN = 3.6V; VOUT = 1.5V; IOUT = 1.2A)
(FB = 0V; VP = VCC)
Operating Current (μA)
VCC = 2.7V
0
Non-Switching IQ vs. Temperature
VCC = 5.5V
V(LX)
2V/div
VCC = 5.0V
170
160
150
140
130
VCC = 3.6V
2
Frequency (kHz)
200
190
180
VCC = 5.0V
10
VCC = 4.2V
VCC = 2.7V
120
110
100
-20
-5
10
25
VCC = 3.6V
40
55
IL
500mA/div
70
85
Temperature (°C)
Time (500ns/div)
Transient Response
Output Ripple
(VIN = 3.6V; VOUT = 1.5V; ILOAD = 0.25 to 1.2A)
VOUT
50mV/div
(VIN = 3.6V; VOUT = 1.5V; IOUT = 0A)
VOUT
5mV/div
BW = 20MHz
Inductor Current
500mA/div
LX
2V/div
Time (20µs/div)
1152.2006.09.1.7
Time (500ns/div)
7
AAT1152
850kHz 1A Buck DC/DC Converter
Typical Characteristics
Output Ripple
Output Ripple
(VIN = 3.6V; VOUT = 1.5V; IOUT = 1A)
(VIN = 5.0V; VOUT = 3.3V; IOUT = 0A)
VOUT
5mV/div
BW = 20MHz
VOUT
5mV/div
BW = 20MHz
LX
2V/div
LX
2V/div
Time (500ns/div)
Time (500ns/div)
Output Ripple
(VIN = 5.0V; VOUT = 3.3V; IOUT = 1A)
VOUT
5mV/div
BW = 20MHz
LX
2V/div
Time (500ns/div)
8
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
Functional Block Diagram
VCC
VP = 2.7V to 5.5V
1.0V REF
FB
OP. AMP
CMP
DH
LOGIC
LX
OSC
DL
Temp.
Sensing
Power
Good
SGND
POK
Applications Information
Control Loop
The AAT1152 is a peak current mode buck converter. The inner wide bandwidth loop controls the peak
current of the output inductor. The output inductor
current is sensed through the P-channel MOSFET
(high side) and is also used for short-circuit and
overload protection. A fixed slope compensation signal is added to the sensed current to maintain stability. The loop appears as a voltage-programmed
current source in parallel with the output capacitor.
The voltage error amplifier output programs the current loop for the necessary inductor current to force
a constant output voltage for all load and line conditions. The feedback resistive divider is internal,
dividing the output voltage to the error amplifier ref-
1152.2006.09.1.7
EN
PGND
erence voltage of 1V. The error amplifier does not
have the large DC gain typical of most error amplifiers. This eliminates the need for external compensation components, while still providing sufficient
DC loop gain for load regulation. The crossover frequency and phase margin are set by the output
capacitor value only.
Soft Start/Enable
Soft start increases the inductor current limit point in
discrete steps when the input voltage or enable
input is applied. It limits the current surge seen at
the input and eliminates output voltage overshoot
(see Figure 1). When pulled low, the enable input
forces the AAT1152 into a low-power, non-switching
state. The total input current during shutdown is
less than 1μA.
9
AAT1152
850kHz 1A Buck DC/DC Converter
Enable
2V/div
VOUT
1V/div
IL
0.5A/div
Time (200μs/div)
Figure 1: Inrush Limit (VIN = 3.6V; VOUT = 1.5V; IL = 1A).
Current Limit and Over-Temperature
Protection
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 switching. The low pass filter R1 and C3 (shown in
schematic Figures 3 and 4) filters the noise associated with power switching.
For overload conditions, the peak input current is
limited. Figure 2 displays the current limit characteristics. 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 internal dissipation becomes
excessive, protecting the device from damage. The
junction over-temperature threshold is 140°C with
15°C of hysteresis.
Output Voltage (V)
3.5
VCC = VP = 5.0V
VO = 3.3V
3
2.5
2
1.5
VCC = VP = 3.6V
VO = 1.5V
1
0.5
0
0
0.5
1
1.5
2
2.5
Output Current (A)
Figure 2: Current Limit Characteristics.
10
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
R5
100k
U1
AAT1152-1.0
VIN+ 3.3V
VP
R1 100
EN
R2
R3
2.55k 1%
VO+ 1.25V 1A
FB
VCC
R4
10k 1%
POK
EN
100k
C2
0.1μF
C1
10μF
POK
LX
L1
2.7μH
LX
SGND PGND
C3, C4, C5
3x 22μF
6.3V
VC1 Murata 10μF 6.3V X5R GRM42-6X 5R106K6.3
C3, C4, C5 MuRata 22μF 6.3V GRM21BR60J226ME39L X5R 0805
L1 Sumida CDRH4D28-2R 7μH
Figure 3: 3.3V to 1.25V Converter.
Efficiency vs. Output Current
R5
100k
(VOUT = 1.5V)
POK
100
U1
AAT1152-1.5
VP
R1 100
R2
C1
10μF
100k
C2
0.1μF
EN
VCC
EN
V O+ 1.5V 1A
FB
L1
4.1μH
POK
LX
SGND PGND
LX
C3, C4, C5
3x 22μF
6.3V
VC1 Murata 10μF 6.3V X5R GRM42-6X5R106K6.3
C3, C4, C5 MuRata 22μF 6.3V GRM21BR60J226ME39L X5R 0805
L1 Sumida CDRH5D 18-4R 1μH
2.7V
80
Efficiency (%)
VIN + 2.7V - 5.5V
60
4.2V
40
3.6V
20
0
10
100
1000
Output Current (mA)
Figure 4: Lithium-Ion to 1.5V Output Converter.
Power Good
The AAT1152 features an integrated POK comparator and open-drain output signal. The POK pin
goes low when the converter output is 12% or more
below its nominal regulation voltage or when the
device is in shutdown. Connect a pull-up resistor
from POK to the converter input or output. Typical
resistor pull-up values range from 100k to 10k.
Inductor
The output inductor is selected to limit the ripple
current to some predetermined value, typically 20%
to 40% of the full load current at the maximum input
1152.2006.09.1.7
voltage. Manufacturer's specifications list both the
inductor DC current rating, which is a thermal limitation, and the peak current rating, which is determined by the saturation characteristics. The inductor should not show any appreciable saturation
under normal load conditions. During overload and
short-circuit conditions, the average current in the
inductor can meet or exceed the ILIMIT point of the
AAT1152 without affecting converter performance.
Some inductors may have sufficient peak and average current ratings yet result in excessive losses
due to a high DCR. Always consider the losses
associated with the DCR and its effect on the total
converter efficiency when selecting an inductor.
11
AAT1152
850kHz 1A Buck DC/DC Converter
For a 1A load and the ripple set to 30% at the maximum input voltage, the maximum peak-to-peak
ripple current is 300mA. The inductance value
required is 3.9μH.
L=
⎛ V ⎞
VOUT
⋅ 1 - OUT
IO ⋅ k ⋅ FS ⎝ VIN ⎠
L=
1.5V
⎛ 1.5V ⎞
⋅11.0A ⋅ 0.3 ⋅ 830kHz ⎝ 4.2V⎠
L = 3.9μH
The factor "k" is the fraction of full load selected for
the ripple current at the maximum input voltage.
The corresponding inductor RMS current is:
⎛
ΔI 2 ⎞
IRMS = ⎜ IO2 +
≈ IO = 1A
12 ⎟⎠
⎝
ΔI is the peak-to-peak ripple current which is fixed by
the inductor selection above. For a peak-to-peak current of 30% of the full load current, the peak current
at full load will be 115% of the full load. The 4.1μH
inductor selected from the Sumida CDRH5D18
series has a 57mΩ DCR and a 1.95A DC current rating. At full load, the inductor DC loss is 57mW, which
amounts to a 3.8% loss in efficiency.
Figure 5: AAT1152 Evaluation
Board Layout Top Layer.
12
Input Capacitor
The primary function of the input capacitor is to provide a low impedance loop for the edges of pulsed
current drawn by the AAT1152. A low ESR/ESL
ceramic capacitor is ideal for this function. To minimize the stray inductance, the capacitor should be
placed as closely as possible to the IC. This keeps
the high frequency content of the input current localized, minimizing radiated and conducted EMI while
facilitating optimum performance of the AAT1152.
Ceramic X5R or X7R capacitors are ideal for this
function. The size required will vary depending on
the load, output voltage, and input voltage source
impedance characteristics. A typical value is around
10μF. The input capacitor RMS current varies with
the input voltage and output voltage. The equation
for the RMS current in the input capacitor is:
IRMS = IO ⋅
VO ⎛
VO ⎞
⋅ 1VIN ⎠
VIN ⎝
The input capacitor RMS ripple current reaches a
maximum when VIN is two times the output voltage
where it is approximately one half of the load current. Losses associated with the input ceramic
capacitor are typically minimal and are not an issue.
Proper placement of the input capacitor can be seen
in the reference design layout in Figures 5 and 6.
Figure 6: AAT1152 Evaluation
Board Layout Bottom Layer.
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
Output Capacitor
Layout Considerations
Since there are no external compensation components, the output capacitor has a strong effect on
loop stability. Larger output capacitance will reduce
the crossover frequency with greater phase margin. For the 1.5V 1A design using the 4.1μH inductor, three 22μF 6.3V X5R capacitors provide a stable output. In addition to assisting stability, the output capacitor limits the output ripple and provides
holdup during large load transitions. The output
capacitor RMS ripple current is given by:
Figures 5 and 6 display the suggested PCB layout
for the AAT1152. The most critical aspect of the
layout is the placement of the input capacitor C1.
For proper operation, C1 must be placed as closely as possible to the AAT1152.
IRMS =
1
2⋅
3
⋅
VOUT ⋅ (VIN - VOUT)
L ⋅ FS ⋅ VIN
For a ceramic capacitor, dissipation due to the
RMS current of the capacitor is not a concern.
Tantalum capacitors with sufficiently low ESR to
meet output voltage ripple requirements also have
an RMS current rating much greater than that
actually seen in this application.
Adjustable Output
For applications requiring an output other than
the fixed outputs available, the 1V version can be
externally programmed. Resistors R3 and R4 of
Figure 3 force the output to regulate higher than
1V. R4 should be 100 times less than the internal
1MΩ resistance of the FB pin. Once R4 is selected, R3 can be calculated. For a 1.25V output with
R4 set to 10.0kΩ, R3 is 2.55kΩ.
Thermal Calculations
There are two types of losses associated with the
AAT1152 output switching MOSFET: switching
losses and conduction losses. Conduction losses
are associated with the RDS(ON) characteristics of
the output switching device. At full load, assuming
continuous conduction mode (CCM), a simplified
form of the total losses is:
PLOSS =
IO2 ⋅ (RDS(ON)H ⋅ VO + RDS(ON)L ⋅ (VIN - VO))
VIN
+ tsw ⋅ FS ⋅ IO ⋅ VIN + IQ ⋅ VIN
Once the total losses have been determined, the
junction temperature can be derived from the ΘJA
for the MSOP-8 package.
R3 = (VO - 1) ⋅ R4 = 0.25 ⋅ 10.0kΩ = 2.55kΩ
1152.2006.09.1.7
13
AAT1152
850kHz 1A Buck DC/DC Converter
Design Example:
Specifications
IOUT
1A
IRIPPLE
30% of full load at max VIN
VOUT
1.5V
VIN
2.7V to 4.2V (3.6V nominal)
Fs
830kHz
Maximum Input Capacitor Ripple:
IRMS = IO ⋅
VO ⎛ VO ⎞ IO
⋅ 1= = 0.5ARMS, VIN = 2 ⋅ VO
VIN ⎝ VIN⎠ 2
P = ESRCOUT ⋅ IRMS2 = 5mΩ ⋅ 0.52A = 1.25mW
Inductor Selection:
L=
⎛ V ⎞
VOUT
1.5V
⎛ 1.5V⎞
⋅ 1 - OUT =
⋅ 1= 3.9μH
IO ⋅ k ⋅ FS ⎝ VIN ⎠
1A ⋅ 0.3 ⋅ 830kHz ⎝ 4.2V⎠
Select Sumida Inductor CDRH5D18 4.1μH 57mΩ 2.0mm height.
ΔI =
⎛ 1.5V ⎞
VO ⎛
V ⎞
1.5V
⋅ 1- O =
⋅ 1= 280mA
VIN ⎠ 4.1μH ⋅ 830kHz ⎝ 4.2V⎠
L ⋅ FS ⎝
IPK = IOUT +
ΔI
= 1A + 0.14A = 1.14A
2
P = IO2 ⋅ DCR = 57mW
Output Capacitor Dissipation:
IRMS =
VOUT ⋅ (VIN - VOUT)
1.5V ⋅ (4.2V - 1.5V)
1
1
⋅
⋅
=
= 82mARMS
L ⋅ FS ⋅ VIN
2⋅ 3
2 ⋅ 3 4.1μH ⋅ 830kHz ⋅ 4.2V
PESR = ESRCOUT ⋅ IRMS2 = 5mΩ ⋅ 0.0822A = 33μW
14
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
AAT1152 Dissipation:
P=
=
IO2 • (RDS(ON)H • VO + RDS(ON)L • (VIN -VO))
VIN
(0.14Ω • 1.5V + 0.145Ω • (3.6V - 1.5V))
3.6V
+ (tsw • FS • IO + IQ) • VIN
+ (20ns • 830kHz • 1.0A + 0.3mA) • 3.6V = 0.203W
TJ(MAX) = TAMB + ΘJA • PLOSS = 85°C + 150°C/W • 0.203W = 115°C
Manufacturer
Part Number
Value
Max DC
Current
DCR
TaiyoYuden
Toko
Sumida
Sumida
MuRata
MuRata
NPO5DB4R7M
A914BYW-3R5M-D52LC
CDRH5D28-4R2
CDRH5D18-4R1
LQH55DN4R7M03
LQH66SN4R7M03
4.7μH
3.5μH
4.2μH
4.1μH
4.7μH
4.7μH
1.4A
1.34A
2.2A
1.95A
2.7A
2.2A
0.038
0.073
0.031
0.057
0.041
0.025
Size (mm)
L×W×H
Type
5.9 × 6.1 × 2.8
Shielded
5.0 × 5.0 × 2.0
Shielded
5.7 × 5.7 × 3.0
Shielded
5.7 × 5.7 × 2.0
Shielded
5.0 × 5.0 × 4.7 Non-Shielded
6.3 × 6.3 × 4.7
Shielded
Table 1: Surface Mount Inductors.
Manufacturer
Part Number
MuRata
MuRata
MuRata
MuRata
GRM40 X5R 106K 6.3
GRM42-6 X5R 106K 6.3
GRM21BR60J226ME39L
GRM21BR60J106ME39L
Value
Voltage
Temp. Co.
Case
10μF
10μF
22μF
10μF
6.3V
6.3V
6.3V
6.3V
X5R
X5R
X5R
X5R
0805
1206
0805
0805
Table 2: Surface Mount Capacitors.
1152.2006.09.1.7
15
AAT1152
850kHz 1A Buck DC/DC Converter
Ordering Information
Output Voltage1
Package
Marking2
Part Number (Tape and Reel)3
1.0V (Adj. VOUT ≥ 1.0V)
1.8V
2.5V
3.3V
MSOP-8
MSOP-8
MSOP-8
MSOP-8
LTXYY
MLXYY
MMXYY
IAXYY
AAT1152IKS-1.0-T1
AAT1152IKS-1.8-T1
AAT1152IKS-2.5-T1
AAT1152IKS-3.3-T1
All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means
semiconductor products that are in compliance with current RoHS standards, including
the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more
information, please visit our website at http://www.analogictech.com/pbfree.
Package Information
MSOP-8
4° ± 4°
4.90 ± 0.10
3.00 ± 0.10
1.95 BSC
0.95 REF
0.60 ± 0.20
PIN 1
3.00 ± 0.10
0.85 ± 0.10
0.95 ± 0.15
10° ± 5°
GAUGE PLANE
0.254 BSC
0.155 ± 0.075
0.075 ± 0.075
0.65 BSC
0.30 ± 0.08
All dimensions in millimeters.
1. Contact Sales for other voltage options.
2. XYY = assembly and date code.
3. Sample stock is generally held on part numbers listed in BOLD.
16
1152.2006.09.1.7
AAT1152
850kHz 1A Buck DC/DC Converter
© Advanced Analogic Technologies, Inc.
AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights,
or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice.
Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech
warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed.
AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737-4600
Fax (408) 737-4611
1152.2006.09.1.7
17