A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 1
www.analogictech.com
General Description
The AAT1218 is a general purpose DC/DC synchronous
boost (step-up) converter providing a tightly regulated
DC output voltage for continuous output currents up to
1A (minimum). The maximum peak current in the boost
switch is limited to a value of 2A (minimum). Operating
input voltage must be less than the output voltage and
in the 0.5V to 5.5V range, making the device well suited
to portable equipment and consumer appliances.
The boost output voltage is programmed from 2.5V to
5.5V with an external resistor divider. Optimized internal
compensation provides fast transient response with no
external components.
Synchronous rectification eliminates the need for an
external rectifier for output voltage less than 4.5V. Low
on-resistance internal switches provide efficiency up to
95%, which minimizes losses and simplifies packaging
and circuit board layout. An inductor, two resistors and
two ceramic output capacitors are all that are required to
implement a DC/DC boost solution.
The switching frequency is internally set to 1.2MHz to
minimize external filter size and optimize switching
losses.
Integrated soft-start ensures minimal inrush current.
The “anti-ring” circuit reduces stray EMI during light
load, discontinuous operation. Input quiescient current is
less than 400A at no load.
The device provides cycle-by-cycle current limit and over-
temperature protection to prevent device over-stress.
The AAT1218 is available in a Pb-free, 12-pin low profile
TDFN33 package with rating from -40°C to 85°C.
Features
2.5V to 5.5V Adjustable Output Voltage
0.5V Minimum Input Voltage
±2% Output Accuracy
No Schottky Diode Required (VOUT < 4.5V)
Up to 95% Efficiency
400A Standby Current
<1A Shutdown Current
Integrated Soft-Start Circuitry Limits Inrush Current
Constant Frequency 1.2MHz Operation
Inductor Height <1.8mm
Small Ceramic Capacitors
Anti-ring Circuit Reduces EMI
Current Mode Control
Fast, Stable Transient Response
No External Compensation
Cycle-by-Cycle Current Limit
Low Inrush Current with 0.7ms Soft-start
Low Output Ripple: <80mVpp for all Loading Conditions
(BW = 25MHz)
Over-Temperature Protection
Adjustable and Fixed Output Versions Available
Delivers 1A to 5V Output from a Single Cell Li+
Battery
Low-profile TDFN33-12 Package
Applications
DVD Players
Hard Disk Drive
MP3 Players
PDA
Portable Computers
Smart Phones
Typical Application
L1
2.2 µH
AAT1218-5.0
EN
GND
FB
CIN
22µF
0805
VIN:3.6V
LX OUT
PGND
VIN
VOUT: 5V @ 1A
COUT
44µF
(2x22µF)
0805
L1 2.2µH
AAT1218-1.2
EN
GND
FB
CIN
22µF
0805
VIN: 3.6V
R2
1.02M
LX OUT
PGND
VIN
VOUT: 5V @ 1A
COUT
44µF
(22µF x2)
0805
R3
324k
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
2 1218.2009.12.1.4
www.analogictech.com
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
2 1218.2009.12.1.4
www.analogictech.com
Pin Description
Pin # Symbol Description
1LX
Switching node tied to drain of internal N-channel MOSFET and source of internal P-channel MOSFET. Con-
nect this pin to the external power inductor.
2, 5 NC No connect.
3 VIN Input voltage for the controller.
4 EN Input enable pin.
6, 7 GND Non-power signal ground pin.
8FB
Feedback input pin. This pin is connected to an external resistor divider which determines the output voltage
setpoint.
9. 10 OUT Output pin; connected to the positive terminal of the output capacitor and to the external resistor divider.
11, 12 PGND Power ground pin. Connect this pin directly to input and output capacitors.
Pin Configuration
TDFN33-12
(Top View)
LX
N/C
VIN
1
EN
N/C
GND
PGND
PGND
OUT
OUT
FB
GND
2
3
4
5
6
12
11
10
9
8
7
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 3
www.analogictech.com
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 3
www.analogictech.com
Absolute Maximum Ratings1
Symbol Description Value Units
LX, VIN, EN, FB Voltage to PGND -0.3 to 6.0 V
PGND Voltage to GND -0.3 to 0.3 V
Operating Junction Temperature Range -40 to 150 °C
Maximum Soldering Temperature (at leads, 10 sec) 300 °C
Thermal Information
Symbol Description Value Units
PDMaximum Power Dissipation2TDFN33-1232000 mW
ΘJA Maximum Thermal Resistance TDFN33-12 50 °C/W
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. Mounted on 1.6mm thick FR4 circuit board.
3. Derate 25mW/°C above 25°C ambient temperature.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
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4 1218.2009.12.1.4
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Electrical Characteristics
VIN = 1.2V, VOUT = 3.3V, COUT = 44F, TA = 25°C unless otherwise noted.
Symbol Description Conditions Min Typ Max Units
VIN
Minimum Start-Up Voltage ILOAD = 1mA 0.85 1 V
Minimum Start-Up Voltage Loaded
ILOAD = 300mA (Resistive) 1.4 V
Operating Input Voltage Range TA = -40°C to +85°C 0.5 VOUT -
0.5 V
VOUT_RANGE Output Voltage Range 2.5 5.5 V
VFB Feedback Voltage TA = -40°C to +85°C 1.164 1.200 1.236 V
IQ
Quiescient Current
Switching, No Load Operation,
Measured from VOUT
0.5 < VIN < VOUT - 0.5V, ILOAD = 0mA 300 700 A
Quiescient Current
Device Disabled (Shut Down) 0.5 < VIN < VOUT - 0.5V, VEN = 0 0.01 1 A
FOSC Switching Frequency 0.95 1.2 1.5 MHz
DC Minimum Operating Duty Cycle 0 %
Maximum Operating Duty Cycle 80 %
ILIMIT NMOS Current Limit TA = -40°C to +85°C 2.0 2.5 A
TSS Soft-Start Time VIN = 3.3V, VOUT = 5V, COUT = 10F 0.7 ms
NMOS Leakage NMOS Switch Leakage 0.1 5.0 A
PMOS Leakage PMOS Switch Leakage 0.1 5.0 A
NMOS On-Resistance NMOS Switch On-Resistance 180 m
PMOS On-Resistance PMOS Switch On-Resistance 250 m
VOUT Line Regulation VIN = 1.5 - (VOUT - 0.5),
ILOAD = 0mA to 1000mA 0.1 %
VOUT Load Regulation VIN = 1.5 - (VOUT - 0.5),
ILOAD = 0mA to 1000mA 0.5 %
VOUT(LINE_TRANSIENT)
Line Transient Response1VIN = 2.5V - 4.5V, VIN = 1V,
dVIN/dt = ±0.2V/s-3 3 % VOUT
VOUT(LOAD_TRANSIENT)
Load Transient Response1VIN = 2.5V, ILOAD = 50mA to 500mA,
dILOAD/dt = ±0.5A/s, CFF = 100pF -10 10 % VOUT
EN
VEN(L)
Logic Input Low Threshold for EN
0.6 V
VEN(H)
Logic Input High Threshold for EN
VOUT = 3.3V 0.85 V
VOUT = 5.0V 1.0
IEN Enable Input Low Current VIN = VOUT = 5.5V -1.0 1.0 A
1. Specifications are guaranteed by design and characterization.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 5
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Typical Characteristics
CIN = 22F, C OUT = 44F; L = 2.2H; TA = 25°C, unless otherwise noted.
AAT1218 ISD vs. Temperature
Temperature (°C)
ISD (µA)
0
0.2
0.4
0.6
0.8
1
85603510-15
-40
AAT1218 IQ vs. Temperature
(VOUT = 5.5V, Measured From VOUT)
Temperature (°C)
IQ_5.5V (µA)
85603510-15
-40
360
365
370
375
380
385
390
VEN(H) vs. Temperature
(VOUT = 5V)
Temperature (°C)
VEN(H) (V)
85603510-15
-40
0.74
0.78
0.82
0.86
0.9
0.94
VEN(L) vs. Temperature
(VOUT = 5.0V)
Temperature (°C)
VEN(L) (V)
85603510-15
-40
0.66
0.70
0.74
0.78
0.82
0.86
AAT1218 VFB vs. Temperature
Temperature (°C)
VFB (V)
85603510-15
-40
1.164
1.173
1.182
1.191
1.200
1.209
1.218
1.227
1.236
Maximum Load Current vs. VIN
Input Voltage (V)
Load Current (mA)
3.352.852.35 4.854.353.851.851.35
0.85
10
100
1000
10000
VOUT = 3.3V
VOUT = 5V
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
6 1218.2009.12.1.4
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
6 1218.2009.12.1.4
www.analogictech.com
Typical Characteristics
CIN = 22F, C OUT = 44F; L = 2.2H; TA = 25°C, unless otherwise noted.
Maximum Load Current at Startup vs. VIN
Input Voltage (V)
Load Current (mA)
3.352.852.35 4.854.353.851.851.35
0.85
10
100
1000
10000
VOUT = 3.3V
VOUT = 5V
AAT1218 3.3V Output Efficiency
ILOAD (mA)
Efficiency (%)
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100 1000
VIN = 1.2V
VIN = 1.5V
VIN = 1.8V
VIN = 2.4V
AAT1218 5.0V Output Efficiency
ILOAD (mA)
Efficiency (%)
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100 1000
VIN = 1.2V
VIN = 1.5V
VIN = 2.4V
AAT1218 5.0V Output Efficiency
ILOAD (mA)
Efficiency (%)
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100 1000 10000
VIN = 3.0V
VIN = 3.3V
VIN = 3.6V
VIN = 4.2V
Load Transient
(VIN = 2.0V; VOUT = 3.3V; COUT = 44µF; CFF = 100pF)
Time (100µs/div)
VOUT
(200mV/div)
ILOAD
(0.25A/div)
3.3V
500mA
50mA
Soft Start Waveform
(VIN = 1.5V; VOUT = 5V; Load = 100mA)
Time (200µs/div)
LX
(4V/div)
VOUT
(4V/div)
IIN
(0.5A/div)
VEN
(1V/div)
0
0
0
0
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 7
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 7
www.analogictech.com
Typical Characteristics
VIN = 3.6V, VOUT = 3.6V, CIN = 22F, C OUT = 44F; L = 2.2H; TA = 25°C, unless otherwise noted.
Anti-Ringing Operation
(VIN = 3V; VOUT = 5V; Load = 10mA)
Time (0.2µs/div)
LX
(2V/div)
VOUT
(AC Coupled)
(20mV/div)
0
0
Power Saving Mode Waveform
(VIN = 3.6V; VOUT = 5V; Load = 5mA)
Time (4µs/div)
LX
(2V/div)
VOUT
(AC Coupled)
(20mV/div)
VIN
(AC Coupled)
(20mV/div)
IL
(250mA/div) 0
0
0
0
PWM Mode Waveform
(VIN = 3.6V; VOUT = 5V; Load = 1A)
Time (0.4µs/div)
LX
(2V/div)
VOUT
(AC Coupled)
(20mV/div)
VIN
(AC Coupled)
(20mV/div)
IL
(1A/div)
0
0
0
0
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
8 1218.2009.12.1.4
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
8 1218.2009.12.1.4
www.analogictech.com
Functional Description
The AAT1218 is a synchronous step-up DC-DC converter.
It utilizes internal MOSFETs to achieve high efficiency
over the full load current range. It operates at a fixed
switching frequency of 1.2MHz, and uses the slope com-
pensated current mode architecture. The device can
operate at 0.5V input after start up. The typical start-up
voltage is 0.85V.
Synchronous Rectification
The AAT1218 integrates a synchronous rectifier to
improve efficiency and eliminate the external rectifier
diode if output voltage is lower than 4.5V. The synchro-
nous rectifier is used to reduce conduction loss contrib-
uted by the forward voltage of the external rectifier
diode. It is implemented by a PMOS driven by a gate
driver with break-before-make timing. When the output
voltage is greater than 4.5V, an external rectifier diode
is necessary for proper operation.
Low Voltage Start-Up
The AAT1218 can start up at supply voltages as low as
1V. During the start-up phase, the internal low voltage
start-up circuitry controls the NMOS switch to soft-start
the device. A comparator (VOUT GOOD Comp) monitors
the output voltage. If VOUT exceeds 2.3V, the device exits
start-up phase and enters normal operation mode. The
internal circuitry power supply of the device is connected
to VIN during start-up phase and automatically switches
to VOUT during normal operation.
Functional Block Diagram
C
OUT
R1
R2
PWM
Logic
Shutdown
Control
+
Comp
EA
+
VOUT
SHUTDOWN
PGND
EN
FB
OUT
Oscillator
1.2MHz
Antiringing
Control
Bandgap
1.2V
Start-Up
Oscillator
+
V
OUT
GOOD
MUX
Current
Sense
Slope
Compensation
To V
IN
2.3V
L1
V
IN
1.4V–5.5V VIN
LX
C
IN
GND
Start-Up
Current Limit
Vss
Soft Start
Enable Logic
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 9
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Integrated Soft-Start
During start-up, the AAT1218's integrated soft-start cir-
cuitry gradually increases the peak inductor current until
it reaches normal operating value. The inrush current
during start-up can thus be minimized.
Current Mode PWM Control
The AAT1218 is based on a slope compensated current
mode control topology. It operates at a fixed frequency
of 1.2MHz. At the beginning of each clock cycle, the main
switch (NMOS) is turned on and the inductor current
starts to ramp up. After the maximum duty cycle or if the
sense current signal is equal to the error amplifier (EA)
output, the main switch is turned off and the synchro-
nous switch (PMOS) is turned on. This control scheme
has intrinsic cycle-by-cycle current limiting, which can
prevent the main switch from overstress and prevent
saturation of the external inductor.
Power Saving Mode
At very light load, the AAT1218 automatically switches
into Power Saving Mode to improve efficiency. In this
mode, the PWM control will skip some pulses to maintain
regulation. If load increases and output voltage drops,
the device will automatically switch back to regular PWM
mode and maintain regulation.
Anti-ringing Control
Anti-ringing circuitry is included to remove the high fre-
quency ringing that appears on the LX pin when the
inductor current decreases to zero. In this case, ringing
on the LX pin is caused by energy stored in parasitics of
the MOSFETs and the inductor. The anti-ringing circuitry
clamps the voltage to battery voltage internally and thus
dampens the ringing.
Device Enable
When EN is set logic high, the AAT1218 begins operation.
If EN is set logic low, the device is goes into shutdown
mode and consumes less than 1A current. After start-
up, the internal circuitry is supplied by VOUT during normal
operation. However, if shutdown mode is enabled, the
internal circuitry will again be supplied by the battery.
Application Information
Setting the Output Voltage
An external resistor divider is used to set the output volt-
age. The output voltage of the switching regulator (VOUT)
is determined by the following equation:
⎛⎞
⎝⎠
VOUT = 1.20V · 1 +
R1
R2
VOUT R1 (Ω) R2 (Ω)
3.3V 1.02M 576k
5.0V 1.02M 324k
Table 1: Resistor Selection Example for Output
Voltage Setting.
Fixed output voltage devices are also available for 3.3V
and 5V outputs. These devices integrate the feedback
network into the die and can save two external resistors.
Do not connect any component to the FB pin and leave
it floating.
Inductor Selection
The AAT1218's high switching frequency of 1.2MHz
allows for small surface mount inductors. For most
designs, the AAT1218 operates with inductors of 2.2H
to 10H depending on input/output voltage and load cur-
rent. First determine the worst case VIN, VOUT
, and IOUT
.
Then use the equation below to select the proper induc-
tor value; assume the converter is operating in continu-
ous current mode and is in steady state:
D = 1 -
VIN
VOUT
IPEAK = IRMS +
ΔI
2
ΔI = VIN · D
L · fSW
is the converter efficiency, IPEAK is the peak inductor
current, I is the peak-peak inductor ripple current, IRMS
is the RMS current of the inductor current. fsw is the
switching frequency, L is the inductance value and D is
the steady state duty cycle.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
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Fit the proper L into the equations to meet the following
criteria:
1. The DC current rating of the inductor must be high-
er than IPEAK to avoid magnetic saturation. Cored
inductor devalues when core temperature increases,
so verify the inductor of choice with its temperature
characteristics in mind.
2. The inductor ripple current I is typically set for
20% to 40% of the peak inductor current.
Higher inductance means less inductor ripple current;
larger size inductors can handle more power. However,
larger size inductors also have higher profiles and are
more expensive. For optimum load transient and effi-
ciency performance, low DCR inductors should be select-
ed. Table 2 lists some surface mount inductors which are
suitable for typical AAT1218 applications.
Input Capacitor
Select a 4.7F to 10F X7R or X5R ceramic capacitor for
the input. The input capacitor provides a low impedance
loop for the edges of pulsed current drawn by the
AAT1218. Low ESR/ESL X7R and X5R ceramic capaci-
tors are ideal for this function. To minimize stray induc-
tance, the capacitor should be placed as close as pos-
sible to the IC. This keeps the high frequency content of
the input current localized, minimizing EMI and input
voltage ripple.
Always examine the ceramic capacitor DC voltage coef-
ficient characteristics to derive the proper value. For
example, the capacitance of a 10F, 6.3V, X5R ceramic
capacitor with 5.0V DC applied is actually about 6F.
Output Capacitor
The output capacitor limits the output ripple and pro-
vides holdup during large load transitions. When choos-
ing the output capacitor, first consider the acceptable
output ripple level (Vtoatal) and solve for COUT from the
equations below; assume that output current remains
constant in steady state:
ΔV =
ΔVTOTAL = ΔV + ΔVESR = ΔV + IOUT · RESR
IOUT · D
COUT · FSW
A 10F to 47F X5R or X7R ceramic capacitor typically
provides sufficient bulk capacitance to stabilize the out-
put during large load transitions and has the ESR and
ESL characteristics necessary for low output ripple.
In addition, the output voltage droop during load tran-
sient is related to the capacitance of the ceramic output
capacitor. A larger output capacitor helps to reduce volt-
age droop.
Rectifier Diode Selection
A rectifier diode must be added (D1 in Figure 1) when the
output voltage is greater than 4.5V. The Schottky diode
is optional for output voltages less than 4.5V, but can
improve efficiency by about 2% to 3%. A low forward
voltage Schottky diode is recommended. Its voltage rat-
ing should be higher than the output voltage. Thus,
diodes with 10V or more reverse voltage are recom-
mended. The diode rated current can be slightly less than
the peak inductor current to save cost and board space.
Manufacturer Part Number
L
(μH)
Max DCR
(mΩ)
Rated DC Current
(A)
Size
WxLxH (mm)
Sumida
2D14
2.2 94 1.50
3.2x3.2x1.553.3 125 1.2
4.7 169 1.0
CR54
2.2 23.4 3.84
5.6x6.1x4.853.3 28.6 3.20
5.0 44.2 2.60
CDRH4D22/HP
2.2 44.3 3.2
5.0x5.0x2.43.5 65.1 2.5
4.7 82.6 2.2
CDRH5D14/HP
2.0 57 3.2
6.0x6.3x1.53.3 96 2.6
5.1 140 2.0
Table 2: AAT1218 Typical Surface Mount Inductors.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
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Load Disconnect in Shutdown
In a conventional synchronous step-up converter, a con-
duction path exists from battery to output through the
body diode of the PMOS during shutdown. To avoid out-
put side circuitry drawing current from VIN, special appli-
cation circuitry such as that shown in Figure 1 is neces-
sary to disconnect the output from VIN during shutdown.
PCB Layout Guidance
The AAT1218 typically operates at 1.2MHz. Since this is
a high frequency for DC-DC converters, PCB layout is
critical to guarantee satisfactory performance. It is rec-
ommended to make traces of the power loop as short
and wide as possible, especially where the switching
node is involved. First, the inductor and input and output
capacitors should be placed close to the IC. Feedback
and shutdown traces should avoid proximity to large AC
signals, e.g. the power inductor and switching nodes.
The optional rectifier diode (D1 in Figure 1 and Figure 2)
can improve efficiency and alleviate the stress on the
integrated PMOS device. The diode should also be close
to the inductor and the chip to form the shortest possible
switching loop. While the two layer PCB shown in Figures
3 and 4 is sufficient for low to moderate power applica-
tions, large and integral multi-layer ground planes are
ideal for high power applications since the large area of
copper has lower resistance and higher thermal dissipa-
tion capability. The converter’s grounds should join at
one point only. Figure 1 illustrates the schematic for a
typical AAT1218 application.
FB
VIN
EN
GND
VOUT
AAT1218
CIN
22μF COUT1
22μF
COUT2
2.2μF
L1 2.2μH
R2
576kΩ
R1
1.02MΩ
VOUT
3.3V
LX
D1 (Optional)
R3 510kΩ
R4
510kΩ
ON/OFF Control
Q1 Si2305DS
Q2
2N3904
PGND
Figure 1: AAT1218 Application Schematic with Load Disconnect Circuit.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
12 1218.2009.12.1.4
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Evaluation Board Schematic
C1
22μF
C4
100pF
Opt.
.
R1
1.02M 576K VOUT = 3.3V
470K VOUT = 3.8V
324K VOUT = 5V
R2
R3
1M
L1 2.2μH
PGND
PGND
1
2
3
ENABLE
JP2
VIN
VOUT
GND
GND
LX
PGND
GND
R10
0R
FB
EN
VIN
LX
VOUT
AAT1218-TDFN33-12
LX
1
N/C
2
VIN
3
EN
4
N/C
5
GND
6GND 7
FB 8
OUT 9
OUT 10
PGND 11
PGND 12
EXP PAD
U1
PGND
D1
B230LA C3
22μF
C2
22μF
Figure 2: AAT1218 Evaluation Board Schematic.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 13
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 13
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Evaluation Board Layout
Figure 3: AAT1218 Evaluation Board Figure 4: AAT1218 Evaluation Board
Top Side Layout. Bottom Side Layout.
Designator Description Footprint Comment
C1 Capacitor, Ceramic, Murata, GRM21BR60J226ME39, X5R, 22F, ±20%, 6.3V 0805 22F
C2 Capacitor, Ceramic, Murata, GRM21BR60J226ME39, X5R, 22F, ±20%, 6.3V 0805 22F
C3 Capacitor, Ceramic, Murata, GRM21BR60J226ME39, X5R, 22F, ±20%, 6.3V 0805 22F
C4 Capacitor, Ceramic, Murata, GRM1885C1H101JA01B, C0G, 100pF, ±5%, 50V 0603 100pF
D1 Schottky Diode, Vishay, B230LA Diode
JP2 Header, 3-Pin SMALLHDR1X3
L1 Inductor, Sumida CDRH4D28 2.2H
R1 Chip Resistor, Panasonic, 1.02M, 1/16W, 1% 0603 1.02M
R2 Chip Resistor, Panasonic, 590K, 1/16W, 1% 0603 590K
R3 Chip Resistor, Panasonic, 1M, 1/16W, 5% 0603 1M
R10 Chip Resistor, Panasonic, 0R, 1/16W, 5% 0603 0R
U1 AAT1218-TDFN33-12, AnalogicTech TDFN33-12 Boost Reg.
Table 3: AAT1218 Evaluation Board Bill of Materials.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
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A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
14 1218.2009.12.1.4
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Ordering Information
Description Package Marking1Part Number (Tape and Reel)2
Adjustable Output Voltage TDFN33-12 2EXYY AAT1218IWP-1.2-T13
Fixed 3.3V Output Voltage TDFN33-12 5PXYY AAT1218IWP-3.3-T13
Fixed 5V Output Voltage TDFN33-12 5RXYY AAT1218IWP-5.0-T13
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/aboutus/quality.php.
Package Information
TDFN33-124
Top View Bottom View
Detail "A"
Side View
3.00
±
0.05
Index Area Detail "A"
1.70
±
0.05
3.00
±
0.05
0.05
±
0.05
0.23
±
0.05
0.75
±
0.05
2.40
±
0.05
Pin 1 Indicator
(optional)
0.43
±
0.05
0.45
±
0.050.23
±
0.05
0.1 REF
C0.3
All dimensions in millimeters.
1. XYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
3. Product not available for U.S. market.
4. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing
process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection.
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 15
www.analogictech.com
A AT 1218
High Current, 1.2MHz Synchronous Boost ConverterSwitchRegTM
PRODUCT DATASHEET
1218.2009.12.1.4 15
www.analogictech.com
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Phone (408) 737-4600
Fax (408) 737-4611
© Advanced Analogic Technologies, Inc.
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