AAT1156
1MHz 700mA Step-Down DC-DC Converter
1156.2005.11.1.2 1
SwitchReg™
General Description
The AAT1156 SwitchReg™ is a member of
AnalogicTech™'s Total Power Management IC™
(TPMIC™) product family. The step-down switching
converter is ideal for applications where high effi-
ciency is required over the full range of load condi-
tions. The 2.7V to 5.5V input voltage range makes
the AAT1 156 ideal for single-cell lithium-ion/polymer
battery applications. Capable of more than 700mA
with internal MOSFETs, the current-mode con-
trolled IC provides high efficiency over a wide oper-
ating range. Fully integrated compensation simpli-
fies system design and lowers external parts count.
The AAT1156 is available in the 16-pin 3x3mm
QFN package and is rated over the -40°C to +85°C
temperature range.
Features
•V
IN Range: 2.7 to 5.5 Volts
• Up to 95% Efficiency
• 110mΩRDS(ON) Internal Switches
• <1µA Shutdown Current
• 1MHz Step-Down Switching Frequency
• Fixed or Adjustable VOUT ≥0.8V
• Integrated Power Switches
• Current Mode Operation
• Internal Compensation
• Stable with Ceramic Capacitors
• Internal Soft Start
• Over-Temperature Protection
• Current Limit Protection
• 16-Pin QFN 3x3mm Package
• -40°C to +85°C Temperature Range
Applications
• Cellular Phones
• Digital Cameras
• MP3 Players
• Notebook Computers
• PDAs
• Wireless Notebook Adapters
Typical Application
AAT1156 Efficiency
(VOUT = 2.5V; L = 4.7µ
µ
H; CDRH3D16)
Output Current (mA)
Efficiency (%)
50
55
60
65
70
75
80
85
90
95
100
1 10 100 1000
VIN = 3.0V
VIN = 3.6V
VIN = 4.2V
4.7µH
L1
2 x 22µF
C3, C4
10µF
C1
100
R1
0.1 µF
C2
C1 Murata 10µF 6.3V X5R GRM42-6X5R106K6.3
C3-C4 MuRata 22µF 6.3V GRM21BR60J226ME39L X5R 0805
2.5VINPUT
L1 Sumida CDRH3D16-4R7NC
187k
R3
59k
R4
LX 14
LL
6
EN
7
VCC
9
VP
10
NC
8
LX 13
PGND 3
VP
12
VP
11
FB 4
LX 15
PGND 2
PGND 1
SGND
5
NC 16
AAT1156
U1
Pin Descriptions
Pin Configuration
QFN33-16
(Top View)
VP
VP
VP
NC
PGND
PGND
PGND
1
2
3
4
LL
SGND
EN
16
15
14
13
5
6
7
8
12
11
10
9
NC
VC
C
LX
LX
LX
FB
Pin # Symbol Function
1, 2, 3 PGND Main power ground return pin. Connect to the output and input capacitor
return. (See board layout rules.)
4 FB Feedback input pin. This pin is connected to the converter output. It is
used to set the output of the converter to regulate to the desired value
via an internal resistive divider. For an adjustable output, an external
resistive divider is connected to this pin on the 1V model.
5 SGND Signal ground. Connect the return of all small signal components to this
pin. (See board layout rules.)
6 LL Mode selector switch. When pulled low, the device enters light load mode.
7 EN Enable input pin. A logic high enables the converter; a logic low forces
the AAT1156 into shutdown mode, reducing the supply current to less
than 1µA. The pin should not be left floating.
8, 16 NC Not internally connected.
9 VCC Bias supply. Supplies power for the internal circuitry. Connect to input
power via low pass filter with decoupling to SGND.
10, 11, 12 VP Input supply voltage for the converter power stage. Must be closely
decoupled to PGND.
13, 14, 15 LX Connect inductor to these pins. Switching node internally connected to
the drain of both high- and low-side MOSFETs.
EP Exposed paddle (bottom); connect to PGND directly beneath package.
AAT1156
1MHz 700mA Step-Down DC-DC Converter
21156.2005.11.1.2
Absolute Maximum Ratings1
Thermal Characteristics
Recommended Operating Conditions
Symbol Description Value Units
T Ambient Temperature Range -40 to 85 °C
Symbol Description Value Units
ΘJA Maximum Thermal Resistance (QFN33-16)350 °C/W
PDMaximum Power Dissipation (QFN33-16)4(TA= 25°C) 2.0 W
Symbol Description Value Units
VCC, V VCC, VPto GND 6 V
VLX LX to GND -0.3 to VP+0.3 V
VFB FB to GND -0.3 to VCC+0.3 V
VEN EN to GND -0.3 to 6 V
TJOperating Junction Temperature Range -40 to 150 °C
VESD ESD Rating2- HBM 3000 V
AAT1156
1MHz 700mA Step-Down DC-DC Converter
1156.2005.11.1.2 3
1. Stresses above those listed in Absolute Maximum Ratings may cause 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 100pF capacitor discharged through a 1.5kΩresistor into each pin.
3. Mounted on a demo board (FR4, in still air).
4. Derate 20mW/°C above 25°C.
Electrical Characteristics
VIN = VCC = VP= 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= 25°C.
Symbol Description Conditions Min Typ Max Units
VIN Input Voltage Range 2.7 5.5 V
VOUT Output Voltage Tolerance VIN = VOUT + 0.2 to 5.5V, -3 3 %
IOUT = 0 to 700mA
VIL Input Low Voltage 0.6 V
VIH Input High Voltage 1.4 V
VUVLO Under-Voltage Lockout VIN Rising, VEN = VCC 2.5 V
VIN Falling, VEN = VCC 1.2
VUVLO(HYS) Under-Voltage Lockout Hysteresis 250 mV
IIL Input Low Current VIN = VFB = 5.5V 1.0 µA
IIH Input High Current VIN = VFB = 0V 1.0 µA
IQQuiescent Supply Current No Load, LL = 0V; VFB = 0V, 220 350 µA
VIN = 4.2V, TA= 25°C
ISHDN Shutdown Current VEN = 0V, VIN = 5.5V 1.0 µA
ILIM Current Limit TA= 25°C 1.2 A
RDS(ON)H High Side Switch On Resistance TA= 25°C 110 150 mΩ
RDS(ON)L Low Side Switch On Resistance TA= 25°C 100 150 mΩ
∆VOUT(VOUT*∆VIN) Load Regulation VIN = 4.2V, ILOAD = 0 to 700mA ±0.9 %
DVOUT/VOUT Line Regulation VIN = 2.7 to 5.5V ±0.1 %/V
FOSC Oscillator Frequency TA= 25°C 750 1000 1350 kHz
TSD Over-Temperature Shutdown 140 °C
Threshold
THYS Over-Temperature Shutdown 15 °C
Hysteresis
AAT1156
1MHz 700mA Step-Down DC-DC Converter
41156.2005.11.1.2
Typical Characteristics
No Load Supply Current vs. Input Voltage
Input Voltage (V)
Supply Current (µ
µ
A)
0
50
100
150
200
250
300
2.5 3 3.5 4 4.5 5 5.5
-40°C
25°C
85°C
Load Transient Response
(50mA-680mA; VIN = 3.6V; VOUT = 0.8V)
Output Voltage
(top) (20mV/div)
Time (10µ
µ
sec/div)
Inductor and Load Current
(bottom) (500mA/div)
0.67
0.69
0.71
0.73
0.75
0.77
0.79
0.81
0.83
Ø
Ø
Line Transient
(IOUT = 500mA; VO = 0.8V)
Input Voltage
(top) (V)
Output Voltage (AC coupled)
(bottom) (mV)
2.8
3
3.2
3.4
3.6
3.8
4
4.2
4.4
-20
-10
0
10
20
30
40
50
60
Time (20µsec/div)
Output Ripple
(0.8V; 700mA; VIN = 3.6V)
Time (250ns/div)
Output Voltage
(AC coupled) (top) (mV)
Inductor Current
(bottom) (A)
-60
-50
-40
-30
-20
-10
0
10
20
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
Soft Start
(0.8V; 700mA; VIN = 3.6V)
Time (100µ
µ
s/div)
Enable and Output Voltage
(top) (V)
Inductor Current
(bottom) (A)
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
Output Ripple
(0.8V; 10mA; VIN = 3.6V)
Time (2µ
µ
s/div)
Output Voltage
(AC coupled) (top) (mV)
Inductor Current
(bottom) (A)
-60
-50
-40
-30
-20
-10
0
10
20
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
AAT1156
1MHz 700mA Step-Down DC-DC Converter
1156.2005.11.1.2 5
Typical Characteristics
N-Channel RDSON vs. Input Voltage
Input Voltage (V)
RDSON (mΩ
Ω
)
0
20
40
60
80
100
120
140
160
180
200
2.5 3.53454.5 5.5
120°C
25°C85°C
100°C
Frequency vs. Input Voltage
Input Voltage (V)
Frequency (MHz)
0.94
0.95
0.96
0.97
0.98
0.99
1
1.01
1.02
2.7 3.2 3.7 4.2 4.7 5.2 5.7
P-Channel RDSON vs. Input Voltage
Input Voltage (V)
RDSON (mΩ
Ω
)
0
20
40
60
80
100
120
140
160
180
200
2.5 3.53454.5 5.5
120°C
25°C85°C
100°C
Frequency vs. Temperature
(VIN = 3.6V)
Temperature (°
°
C)
Frequency (MHz)
0.6
0.7
0.8
0.9
1
1.1
1.2
-40 -20 0 20 40 60 80 100
DC Regulation
(VOUT = 0.6V)
Output Current (A)
Output Error (%)
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
0.0001 0.001 0.01 0.1 1
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
Output Voltage vs. Temperature
(VIN = 4.2V; VOUT = 0.8V; 400mA VOUT)
Temperature (°
°
C)
Output Voltage Error (%)
-0.4
-0.3
-0.2
-0.1
0.1
0.0
-40 -20 0 20 40 60 80 100
AAT1156
1MHz 700mA Step-Down DC-DC Converter
61156.2005.11.1.2
AAT1156
1MHz 700mA Step-Down DC-DC Converter
1156.2005.11.1.2 7
Functional Block Diagram
VP= 2.7V to 5.5VVCC
ENSGND PGND
LOGIC
1.0V REF
Temp.
Sensing
OSC
OP. AMP
L
X
FB DH
DL
CMP
1MΩ
LL
Operation
Control Loop
The AAT1156 is a peak current mode step-down
converter. The inner, wide bandwidth loop controls
the inductor peak current. The 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 st ability for
duty cycles greater than 50%. The loop appears
as a voltage-programmed current source in paral-
lel 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 external volt age feedback resistive
divider divides the output voltage to the error ampli-
fier reference voltage of 0.6V. The voltage error
amplifier DC gain is limited. This eliminates the
need for external compensation components, while
still providing sufficient DC loop gain for good load
regulation. The voltage loop crossover frequency
and phase margin are set by the output capacitor.
Soft Start/Enable
Soft st art increases the inductor current limit point in
discrete steps once the input voltage or enable
input is applied. It limits the current surge seen at
the input and eliminates output voltage overshoot.
When pulled low, the enable input forces the
AAT1156 into a non-switching shutdown state. The
total input current during shut down is less than 1µA.
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 C2 (shown in the
schematic in Figure 1) filters the input noise asso-
ciated with the power switching.
AAT1156
1MHz 700mA Step-Down DC-DC Converter
81156.2005.11.1.2
Current Limit and Over-Temperature
Protection
For overload conditions, the peak input current is lim-
ited. 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.
Inductor
The output inductor is selected to limit the ripple cur-
rent to a predetermined value, typically 20% to 40%
of the full load current at the maximum input 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. Some inductors may meet the peak and
average current ratings yet result in excessive losses
due to a high DCR. Always consider the losses asso-
ciated with the DCR and its effect on the total con-
verter efficiency when selecting an inductor.
For a 0.7A, 1.5V output with the ripple set to 40%
at a maximum input voltage of 4.2V, the maximum
peak-to-peak ripple current is 280mA. The induc-
tance value required is 3.44µH.
The factor "k" is the fraction of full load selected for
the ripple current at the maximum input voltage.
For ripple current at 40% of the full load current, the
peak current will be 120% of full load. Selecting a
standard value of 3.3µH gives 42% ripple current.
A 3.3µH inductor selected from the Sumida
CDRH3D16 series has a 63mΩDCR and a 1.1A
DC current rating. At full load, the inductor DC loss
is 31mW which amounts to less than 3% loss in
efficiency for a 0.7A, 1.5V output.
Input Capacitor
The primary function of the input capacitor is to pro-
vide a low impedance loop for the edges of pulsed
current drawn by the AAT1156. A low ESR/ESL
ceramic capacitor is ideal for this function. To mini-
mize stray inductance, the capacitor should be
placed as closely as possible to the IC. This keeps
the high frequency content of the input current local-
ized, minimizing radiated and conducted EMI while
facilitating optimum performance of the AAT1156.
Ceramic X5R or X7R capacitors are ideal for this
function. The size required will vary depending on
V
OUT
V
OUT
1.5
V
1.5V
L = ⋅ 1 -
L = 3.44µH
L = ⋅ 1 -
I
O
⋅ k ⋅ F
V
IN
0.7A ⋅ 0.4 ⋅ 1MHz
4.2V
⎝
⎠
⎛
⎝⎞
⎠
Figure 1: AAT1156 Evaluation Board Schematic—Lithium-Ion to 2.5V Converter.
4.7µH
L1
2 x 22µF
C3, C4
10µF
C1
100
R1
0.1 µF
C2
C1 Murat a 10µF 6.3V X5R GRM42-6X5R 106K6.3
C3, C4 MuRata 22µF 6.3V GRM21BR60J226ME396 X5R 0805
Vout+Vin+
L1 Sumida CDRH3D16-4R 7NC
14
LL
6
EN
7
VCC
9
VP
10
N/C
8
13
3
VP
12
VP
11
4
15
2
1
SGND
PGND
LX
N/C
LX
PGND
FB
LX
PGND
5
16
AAT1156
U1
100k
R6
200k
R3
59k
R4
Enable
100K
R2
LL
the load, output voltage, and input voltage source
impedance characteristics. Values range from 1µF
to 10µF. The input capacitor RMS current varies
with the input voltage and output volt age. The equa-
tion for the RMS current in the input capacitor is:
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 cur-
rent. Losses associated with the input ceramic
capacitor are typically minimal and are not an
issue. Proper placement of the input capacitor is
shown in the reference design layout in Figure 2.
Output Capacitor
Since there are no external compensation compo-
nents, 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, 0.7A design using the 3.3µH inductor,
two 22µF capacitors provide a stable output. In
addition to assisting in stability, the output capacitor
limits the output ripple and provides holdup during
large load transitions. The output capacitor RMS
ripple current is given by:
For an X7R or X5R ceramic capacitor, the ESR is
so low that dissipation due to the RMS current of
the capacitor is not a concern. Tantalum capacitors
with sufficiently low ESR to meet output volt age rip-
ple requirements also have an RMS current rating
well beyond that actually seen in this application.
Layout
Figures 2 and 3 display the suggested PCB layout
for the AAT1156. The following guidelines should
be used to help ensure a proper layout.
1. The input capacitor (C1) should connect as
closely as possible to VP(Pins 10, 11, and 12)
and PGND (Pins 1, 2, and 3).
2. C3, C4, and L1 should be connected as closely
as possible. The connection from L1 to the LX
node should be as short as possible.
3. The feedback trace (Pin 4) should be separate
from any power trace and connect as closely
as possible to the load point. Sensing along a
high-current load trace will degrade DC load
regulation.
4. The resistance of the trace from the load return
to the PGND (Pins 1, 2, and 3) should be kept
to a minimum. This will help to minimize any
error in DC regulation due to differences in the
potential of the internal signal ground and the
power ground.
5. Low pass filter R1 and C2 provide a cleaner
bias source for the AAT1156 active circuitry.
C2 should be placed as closely as possible to
SGND (Pin 5) and VCC (Pin 9).
V
OUT
⋅
(V
IN
- V
OUT
)
1
I
RMS
=
⋅
L
⋅
F
⋅
V
IN
2
⋅
3
V
O
⎛
V
O
⎞
I
RMS
= I
O
⋅ ⋅ 1 -
V
IN
⎝ V
IN
⎠
AAT1156
1MHz 700mA Step-Down DC-DC Converter
1156.2005.11.1.2 9
Figure 2: QFN Evaluation Board Top Side. Figure 3: QFN Evaluation Board Bottom Side.
Thermal Calculations
There are three types of losses associated with the AAT1156: MOSFET switching losses, conduction losses,
and quiescent current losses. The conduction losses are due to the RDS(ON) characteristics of the internal P-
and N-channel MOSFET power devices. At full load, assuming continuous conduction mode (CCM), a simpli-
fied form of the total losses is given by:
where IQis the AAT1156 quiescent current.
Once the total losses have been determined, the junction temperature can be derived from the θJA for the
QFN33-16 package.
Adjustable Output
Resistors R3 and R4 of Figure 1 force the output to regulate higher than 0.6V. The optimum value for R4 is
59kΩ. Values higher than this may cause problems with stability, while lower values can degrade light load
efficiency. For a 2.5V output with R4 set to 59kΩ, R3 is 187kΩ.
Figure 4: R3 vs. VOUT for Adjustable Output Using the AAT1156.
Output Voltage (V)
R3 (kΩ
Ω
)
0
50
100
150
200
250
300
350
400
450
500
1 1.5 2 2.5 3.53 4 4.5 5 5.
5
R4=59kΩ
⎛⎞
⎝⎠
R3 = -1 · R4 = - 1 · 59kΩ = 187kΩ
VO
VREF
⎛⎞
⎝⎠
2.5V
0.6V
TJ= P · ΘJA + TAMB
IO2 ⋅ (RDSON(HS) ⋅ VO + RDSON(LS) ⋅ (VIN - VO))
P = + (tsw ⋅ F ⋅ IO ⋅ VIN + IQ) ⋅ VIN
VIN
AAT1156
1MHz 700mA Step-Down DC-DC Converter
10 1156.2005.11.1.2
Design Example
Specifications
IOUT 0.7A
IRIPPLE 40% of Full Load at Max VIN
VOUT 2.5V
VIN 2.7V to 4.2V (3.6V nominal)
FS1MHz
TAMB 85°C
Maximum Input Capacitor Ripple:
Inductor Selection:
Select Sumida inductor CDRH3D16 or CDRH4D28 4.7µH.
V
O
V
O
2.5
V
2.5V
∆I = ⋅ 1 - = ⋅ 1- = 220mA
L ⋅ F
V
IN
4.7µH ⋅ 1MHz
4.2V
I
PK
= I
OUT
+ ∆I = 0.7A + 0.11A = 0.81A
2
P = I
O2
⋅ DCR = (0.7A)
2
⋅ 80mΩ = 40mW
⎛
⎝⎞
⎠
⎛
⎝⎞
⎠
V
OUT
V
OUT
2.5
V
2.5V
L = ⋅ 1 - = ⋅ 1 - = 4.82µH
I
O
⋅ k ⋅ F
V
IN
0.7A ⋅ 0.3 ⋅ 1MHz
4.2V
⎛
⎝⎞
⎠⎛
⎝⎞
⎠
1 0.34Arms, VIN = 2 x VO
OO
RMS O
IN IN
VV
II
VV
⎛⎞
=· · -=
⎝⎠
P = esr · IRMS
2 = 5mΩ · 0.342 A = 0.6mW
AAT1156
1MHz 700mA Step-Down DC-DC Converter
1156.2005.11.1.2 11
AAT1156
1MHz 700mA Step-Down DC-DC Converter
12 1156.2005.11.1.2
Output Capacitor Ripple Current:
AAT1156 Dissipation:
Figure 5: 0.8V Solution.
AAT1156 Efficiency
(VOUT = 0.8V; L = 2.2µ
µ
H; CDRH3D16)
Output Current (mA)
Efficiency (%)
20
30
40
50
60
70
80
90
100
1 10 100 1000
VIN = 2.7V
VIN = 3.6V
VIN = 4.2V
2.2µH
L1
2 x 22µF
C3, C4
10µF
C1
100
R1
0.1 µF
C2
C1 Murat a 10µF 6.3V X5R GRM 42-6X5R 106K6.3
C3, C4 MuRata 22µF 6.3V GRM21BR60J226ME39L X5R 0805
0.8VINPUT
L1 Sumida CD RH3D16-2R2NC
19.6k
R3
59k
R4
14
LL
6
EN
7
VCC
9
VP
10
N/C
8
13
3
VP
12
VP
11
4
15
2
1
SGND
PGND
LX
N/C
LX
PGND
FB
LX
PGND
5
16
AAT1156
U1
TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + 50°C/W · 0.141W = 92°C
PTOTAL + (tsw · F · IO + IQ) · VIN
IO2 · (RDSON(HS) · VO + RDSON(LS) · (VIN -VO))
VIN
=
=+ (20nsec · 1MHz · 0.7A + 300µA) · 4.2V = 0.141W
(0.7A)2 · (0.17Ω · 2.5V + 0.16Ω · (4.2V - 1.5V))
4.2V
1
23
1 2.5V · (4.2V - 2.5V)
4.7µH · 1MHz · 4.2V
23
RMS
IN
ILFV
=·
··
·· = 62mArms
·
VOUT · (VIN - VOUT)=
Pesr = esr · IRMS2 = 5mΩ · (62 mA)2 = 19µW
Surface Mount Inductors
Surface Mount Capacitors
Manufacturer Part Number Value Voltage Temp. Co. Case
MuRata GRM40 X5R 106K 6.3 10µF 6.3V X5R 0805
MuRata GRM42-6 X5R 106K 6.3 10µF 6.3V X5R 1206
MuRata GRM21BR60J226ME39L 22µF 6.3V X5R 0805
Max DC Size (mm)
Manufacturer Part Number Value Current DCR L x W x H Type
TaiyoYuden NPO5DB4R7M 4.7µH 1.4A 0.038 5.9x6.1x2.8 Shielded
Toko A914BYW-3R5M-D52LC 3.5µH 1.34A 0.073 5.0x5.0x2.0 Shielded
Sumida CDRH4D28-4R7 4.7µH 1.32A 0.072 4.7x4.7x3.0 Shielded
Sumida CDRH3D16-2R2 2.2µH 1.2A 0.050 3.8x3.8x1.8 Shielded
Sumida CDRH3D16-3R3 3.3µH 1.1A 0.063 3.8x3.8x1.8 Shielded
Sumida CDRH3D16-4R7 4.7µH 0.9 0.080 3.8x3.8x1.8 Shielded
Sumida CDRH5D28-4R2 4.2µH 2.2A 0.031 5.7x5.7x3.0 Shielded
Sumida CDRH5D18-4R1 4.1µH 1.95A 0.057 5.7x5.7x2.0 Sielded
MuRata LQH55DN4R7M03 4.7µH 2.7A 0.041 5.0x5.0x4.7 Non-Shielded
MuRata LQH66SN4R7M03 4.7µH 2.2A 0.025 6.3x6.3x4.7 Shielded
AAT1156
1MHz 700mA Step-Down DC-DC Converter
1156.2005.11.1.2 13
Ordering Information
Package Information
3.000 ± 0.05
Pin 1 Dot By Marking
1.55 ± 0.15
0.400 ± 0.05
3.000 ± 0.05 0.500 ± 0.05
0.850 ± 0.05
Pin 1 Identification
0.025 ± 0.025
0.203 ± 0.0254
0.230 ± 0.05
Top View Bottom View
Side View
1
13
5
9
Output Voltage Package Marking1Part Number (Tape and Reel)2
0.6V (Adj VOUT ≥0.8V) QFN33-16 LUXYY AAT1156IVN-T1
AAT1156
1MHz 700mA Step-Down DC-DC Converter
14 1156.2005.11.1.2
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737-4600
Fax (408) 737-4611
1. XYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
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