AAT2265IJS-3.3-T1 - AnalogicTech

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

2265.2009.05.1.1 1

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General Description

The AAT2265 is designed for single-cell or dual-cell alka-

line, NiMH or NiCd battery-powered applications. It is a

high efficiency, synchronous, high frequency, step-up con-

verter with true output disconnect during shutdown

(<1.0μA), start-up inrush current limit, and limited short-

circuit protection.

The high 2MHz switching frequency and completely inte-

grated control circuitry minimize the total solution foot-

print area while maintaining excellent regulation, ripple,

and transient response throughout the full load range.

Light load switching frequency modulation and low qui-

escent current maintain high efficiency performance for

light load and sleep mode conditions.

With a 1A peak switch current limit, the AAT2265 is

capable of delivering 100mA to the load with a single AA

cell battery or up to 250mA from dual AA cell batteries.

The device has a 1.0V start-up voltage with operation

down to 0.8V, making it ideal for battery operated con-

sumer products that require higher voltages by replacing

two AA batteries with a single AA cell.

The AAT2265 is available in a Pb-free, space-saving

2.0x2.1mm 8-pin SC70JW package and is rated over the

-40°C to +85°C temperature range.

Features

• 100mA Output from a Single AA Cell Input

• 250mA Output from a Dual AA Cell Input

• VIN Operation Range: 0.8V to VOUT

• Up to 93% Efficiency

• Low Start-Up Voltage: 1.0V Typical

• Internal Synchronous Rectifier

• Current Mode Control with Internal Feedback and

Compensation

• 2MHz Switching Frequency

• 1A Current Limit

• Maintains High Efficiency Over the Output Current

Range for Improved Battery Life

• Low 65μA No Load Bias Current

• True Load Disconnect

• Limited Short-Circuit and Over-Current Protection

• Inrush Current Limit and Current Limited Soft Start

• Low Shutdown Current: <1.0μA

• -40°C to +85°C Temperature Range

• 2.0x2.1mm SC70JW-8 Package

Applications

• Bluetooth® Headsets

• Digital Cameras

• Medical Instruments

• Mobile Handsets

• MP3 and Portable Music Players

• Single AA Cell Consumer Products

Typical Application

2.2μH

4.7μF

VIN VOUT

VCC

VIN

OUT

GND

AAT2265

Dual-Cell to 3.3V Efficiency vs. Output Current

(VOUT = 3.3V; L = 2.2µH)

Output Current (mA)

Efficiency (%)

100

0.1 1 10 100 1000

VIN = 2.0V

VIN = 2.4V

VIN = 2.7V

VIN = 3.0V

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

2 2265.2009.05.1.1

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Pin Descriptions

Pin # Symbol Function

1 VCC Bias supply voltage after start-up and feedback to the output voltage error ampliﬁ er.

2EN

Enable pin. Logic high enables the IC. Logic low disables the IC and disconnects the load from the input.

Shutdown current is <1μA.

3 VIN Battery input voltage. Supplies the IC at start-up.

4LX

Inductor connection. Ties to the drains of the P-channel synchronous rectiﬁ er and the N-channel MOSFET

switch.

5 OUT Boost converter output voltage; connects to the P-channel synchronous MOSFET source. Bypass with

ceramic capacitor to GND.

6, 7, 8 GND Signal and power ground. Connect output capacitor return.

Pin Configuration

SC70JW-8

(Top View)

VIN

GND

OUT

VCC 1

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Absolute Maximum Ratings

Symbol Description Value Units

VNVIN, OUT, VCC, EN, LX to GND -0.3 to 6.0 V

TJJunction Temperature Range -40 to 150 °C

TOP Operating Temperature Range -40 to 85 °C

TLEAD Maximum Soldering Temperature (at leads, 10 sec) 300 °C

Thermal Characteristics1

Symbol Description Value Units

θJA Maximum Thermal Resistance 160 °C/W

PDMaximum Power Dissipation 625 mW

1. Mounted on an FR4 board.

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Electrical Characteristics1

VIN = 1.2V, TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.

Symbol Description Conditions Min Typ Max Units

VIN

Minimum Start-Up Voltage ILOAD = 1mA; VOUT = 3.3V 1.0 V

Operating Input Voltage Range IOUT ≤ 50mA 0.8 VOUT

VOUT Output Voltage Accuracy VIN = 1.0V to 2.5V, PWM Mode; VOUT

= 3.3V VOUT - 0.1 VOUT + 0.1 V

Quiescent Supply Current (Light Load

Operation)2

No Load 65 115 μA

ISHDN Shutdown Current EN = 0V, VIN = 3.3V 1.0 μA

RDS(ON)H PMOS On-Resistance TA = 25°C 750 mΩ

RDS(ON)L NMOS On-Resistance TA = 25°C 400 mΩ

ILIMIT NMOS Current Limit 0.6 1.0 A

IPFM PFM Light Load Current Threshold 20 mA

ηEfﬁ ciency IOUT = 50mA, L = 2.2μH, VIN = 1.8V 89 %

ΔVOUT/

VOUT

Load Regulation ILOAD = 0 to 100mA 1.5 %

ΔVOUT/

VOUT/ΔVIN

Line Regulation VIN = 0.8V to 2.5V; IOUT = 50mA 0.2 %/V

FOSC Switching Frequency TA = 25°C 1.8 2.0 2.2 MHz

DTYMAX Maximum Duty Cycle 90 %

VTH(L-IN) Logic Input Low Threshold for EN 0.4 V

VTH(H-IN) Logic Input High Threshold for EN 1.0 V

1. The AAT2265 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correla-

tion with statistical process controls.

2. IQ = IQ_VOUT + IQ_VCC.

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Typical Characteristics

Single-Cell to 3.3V Efficiency vs. Output Current

(VOUT = 3.3V; L = 2.2µH)

Output Current (mA)

Efficiency (%)

100

0.1 1 10 100 1000

VIN = 1.2V

VIN = 1.5V

VIN = 1.8V

Single-Cell to 3.3V Load Regulation

(VOUT = 3.3V; L = 2.2µH)

Output Current (mA)

VOUT Error (%)

0.1 1 10 100 1000

-3

-2

-1

VIN = 1.2V

VIN = 1.5V

VIN = 1.8V

Dual-Cell to 3.3V Efficiency vs. Output Current

(VOUT = 3.3V; L = 2.2µH)

Output Current (mA)

Efficiency (%)

100

0.1 1 10 100 1000

VIN = 2.0V

VIN = 2.4V

VIN = 2.7V

VIN = 3.0V

Dual-Cell to 3.3V Load Regulation

(VOUT = 3.3V; L = 2.2µH)

Output Current (mA)

VOUT Error (%)

0.1 1 10 100 1000

-3

-2

-1

VIN = 2.0V

VIN = 2.4V

VIN = 2.7V

VIN = 3.0V

Line Transient Response

(VIN = 1.9V to 2.4V; VOUT = 3.3V; IOUT = 50mA; COUT = 4.7µF)

Time (100µs/div)

Input Voltage (top) (V)

Output Voltage (bottom) (V)

1.4

1.9

2.4

2.9

3.20

3.25

3.30

3.35

Load Transient Response

(VIN = 1.2V; VOUT = 3.3V; IOUT = 50mA to 100mA; COUT = 4.7µF)

Time (200µs/div)

Output Voltage (top) (V)

Output Current (bottom) (A)

3.2

3.3

3.4

3.5

0.00

0.05

0.10

0.15

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Typical Characteristics

No Load Input Current vs. Input Voltage

(VEN = VIN; VOUT = 3.3V)

Input Voltage (V)

Input Current (µA)

0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0

120

150

180

210

240

270

300

Maximum Load Current Capability for a

4% Drop in Output Voltage vs. Input Voltage

(VOUT = 3.3V)

Input Voltage (V)

Load Current (mA)

1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0

100

200

300

400

500

600

Switching Frequency vs. Temperature

(VIN = 2V; IOUT = 100mA)

Temperature (°C)

Frequency Variation (%)

-50 -20 10 40 70-35 -5 25 55 85

-15

-10

-5

VIH and VIL vs. Input Voltage

Input Voltage (V)

VIH and VIL (V)

0.55

0.60

0.65

0.70

0.75

0.80

0.8 1.6 2.4 3.21.2 2.0 2.8 3.6

VIH

VIL

Minimum Start-Up Input Voltage

vs. Load Current

Load Current (mA)

Input Voltage (V)

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

0 20 40 60 80 100 120 140 160

Constant Current Load

Resistive Load

Output Voltage Error vs. Temperature

(VIN = 1.5V; VOUT = 3.3V)

Temperature (°C)

Output Voltage Error (%)

-40 0 40 80-20 20 60 100

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

IOUT = 1mA

IOUT = 10mA

IOUT = 50mA

IOUT = 100mA

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

2265.2009.05.1.1 7

www.analogictech.com

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

2265.2009.05.1.1 7

www.analogictech.com

Typical Characteristics

Full Load Output Ripple

(VIN = 1.2V; VOUT = 3.3V; IOUT = 100mA)

Time (200ns/div)

VOUT (top) (V)

VLX (middle) (V)

Inductor Current (bottom) (A)

3.28

3.30

3.32

0.2

0.4

0.6

3.3V

Light Load Output Ripple

(VIN = 1.2V; VOUT = 3.3V; IOUT = 10mA)

Time (5µs/div)

VOUT (top) (V)

VLX (middle) (V)

Inductor Current (bottom) (A)

3.28

3.30

3.32

0.0

0.2

0.4

3.3V

Soft-Start Inrush Current

(VIN = 2.4V; VOUT = 3.3V; IOUT = 100mA)

Time (50µs/div)

Output Voltage (top) (V)

Enable Voltage (middle) (V)

Input Current (bottom) (A)

0.0

0.2

0.4

Soft-Start Inrush Current

(VIN = 1.2V; VOUT = 3.3V; IOUT = 40mA)

Time (500µs/div)

Output Voltage (top) (V)

Enable Voltage (middle) (V)

Input Current (bottom) (A)

0.0

0.2

0.4

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

8 2265.2009.05.1.1

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Functional Description

The AAT2265 synchronous step-up converter is targeted

for single- or dual-cell alkaline, NiMH and NiCd battery

applications. It has a 1V typical start-up voltage with

operation after start-up to 0.8V.

The high 2MHz switching frequency of the AAT2265

facilitates output filter component size reduction for

improved power density and reduced overall footprint. It

also provides greater bandwidth and improved transient

response over other lower frequency step-up converters.

The compensation and feedback is integrated with only

three external components (CIN, COUT

, L).

Low RDS(ON) synchronous power switches provide high

efficiency for heavy load conditions. Switching frequency

modulation and low quiescent current maintains this

high efficiency for light load and sleep mode conditions.

In addition to the improved efficiency, the synchronous

boost has the added performance advantage of true load

disconnect during shutdown (<1μA shutdown current),

inrush current limit, and short-circuit protection.

PWM / Light Load Control

The AAT2265 is a high frequency PWM peak current mode

control step-up converter. For light load conditions (10 to

20mA and below), the converter transitions to a variable

frequency (Light Load) mode to reduce the dominant

switching losses. In addition to Light Load operation, a

zero current comparator blocks reverse current in the

P-channel synchronous MOSFET, forcing DCM operation at

light load. These controls, along with very low quiescent

current, help to maintain high efficiency over the com-

plete load range without the compromise of increased

output voltage ripple during light load conditions.

Functional Block Diagram

Voltage

Reference

Logic

VREF

OUT

GND

Comp.

VINVCC

Mode

Control

Low Voltage

Start-Up

Current Limit

Current

Sense

Error

Amp.

2MHz

Oscillator

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Start-up and Inrush Current Limit

The start-up sequence of the AAT2265 varies depending

upon whether the input voltage is greater than or less

than 2V. Above 1V, a start-up oscillator operating at 25%

duty cycle controls the synchronous power stage and

charges the output to 2V. For an input voltage greater

than 2V, the output is charged at a constant current of

300mA until the output reaches a voltage level just below

the input voltage. The step-up converter then takes con-

trol and continues to charge the output to the steady-

state voltage. The step-up converter N-channel switch

current is limited to 1A and the typical start-up time is

approximately 1ms dependant upon load conditions.

Shutdown and Output Disconnect

A typical synchronous step-up (boost) converter has a

conduction path from the input to the output via the

body diode of the P-channel MOSFET. The AAT2265

design disconnects this body diode from the output and

eliminates this conduction path. This enables the

AAT2265 to provide true load disconnect during shut-

down and inrush current limit at turn-on.

Short-Circuit Protection

The AAT2265 is designed to function from a single AA

cell battery which is typically in the range of 1.5V to 0.8V

during discharge. The part is guaranteed to operate at

0.8V with less than 50mA load current because the con-

trol circuitry is powered off the output of the boost. This

unique mode of operation allows the device to run down

to very low input voltages while maintaining control of

regulation, temperature and short circuit protection. The

P-channel synchronous MOSFET body diode disconnect

feature also gives the AAT2265 the ability to provide

limited output short-circuit current protection. However,

when the output is shorted directly to ground, there is a

loss of control circuitry, so the short circuit protection is

limited by the current source of the battery. For single

cell AA, the device can withstand a dead short. But

since the control circuitry is not functional during the

short circuit event, the part can be damaged if a source

greater than an AA battery is used to power the device.

A resistive short where the output does not go below

approximately 2V will be short circuit protected even at

higher than 1.5V input voltage levels.

Applications Information

Inductor Selection

The AAT2265 is designed to operate with a 2.2μH induc-

tor for all input/output voltage combinations. The induc-

tor saturation current rating should be greater than the

NMOS current limit specification listed in the Electrical

Characteristics table. If necessary, the peak inductor cur-

rent can exceed the saturation level by a small amount

with no significant effect on performance. Table 1 pro-

vides a list of some suggested inductor manufacturers

and their part numbers.

Output and Input Capacitor Selection

Surface mount X5R or X7R ceramic capacitors are sug-

gested for both the output and the input. For the output

capacitor (C1 in Figure 4) a 4.7μF, 10V, X5R ceramic

capacitor is necessary for stability, transient response,

and ripple performance. The same 0805 sized capacitor

is used for the input (C2 of Figure 4). If desired, a

smaller, 0603 sized, 4.7μF, 6.3V, X5R ceramic capacitor

can be substituted for the input capacitor (C2). Suggested

ceramic capacitor suppliers are listed in Table 1.

PCB Layout Guidelines

Figures 1, 2, and 3 display the evaluation board layout

and suggested component placement. Due to the high

switching speed of the AAT2265, it is important that the

evaluation board layout be followed. Even the best

switch-mode power supply design cannot overcome the

problems that can be caused by a poor layout.

For the AAT2265, it is necessary that C1 and C2 be

placed as close as possible to the IC with a good low

impedance path to the GND pins of the IC. It is also

good practice to minimize the length of the trace from

the OUT pin to the output inductor. This prevents switch-

ing noise from radiating into other high noise sensitive,

high impedance circuits.

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Figure 1: AAT2265 Evaluation Board Figure 2: Component Placement.

Top Side.

Figure 3: AAT2265 Evaluation Board

Bottom Side.

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Advanced Analogic Technologies, Inc.

3230 Scott Boulevard, Santa Clara, CA 95054

Phone (408) 737-4600

Fax (408) 737-4611

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 speciﬁ cations or to discontinue any product or service without notice. Except as provided in AnalogicTech’s terms and

conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties

relating to ﬁ tness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate

design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to

support this warranty. Speciﬁ c 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.

2.2μH

4.7μF

U1 AAT2265 SC70JW-8

L1 SD3118-2R2

C1, C2 4.7μF 10V 0805 X5R

VOUT

VIN

Enable

VCC

VIN

4OUT 5

GND 6

GND 7

GND 8

AAT2265

Figure 4: AAT2265 Evaluation Board Schematic.

Manufacturer Value Part Voltage Case Size Part Number

Murata

www.murata.com 4.7μFOutput or Input Capacitor 10V 0805 GRM21BR61A475KA73L

Input Capacitor 6.3V 0603 GRM188R60J475KE19D

TDK

www.tdk.com 4.7μFOutput or Input Capacitor 10V 0805 C2012X5R1A475K

Input Capacitor 6.3V 0603 C1608X5ROJ475K

Taiyo Yuden

www.t-yuden.com 4.7μFOutput or Input Capacitor 10V 0805 LMK212BJ475MG

Input Capacitor 6.3V 0603 JMK107BJ475MA

Manufacturer Value Part ISAT DCR Case Size Part Number

Sumida

www.sumida.com 2.2μH Inductor 1.50A 75mΩ3.2 x 3.2 x 1.55 CDRH2D14-2R2

Cooper Electronics

www.cooperet.com 2.2μH Inductor 1.62A 69mΩ3.1 x 3.1 x 1.85 SD3118-2R2

Table 1: Suggested Component Selection.

AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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AAT2265

Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW PackageSwitchRegTM

PRODUCT DATASHEET

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Advanced Analogic Technologies, Inc.

3230 Scott Boulevard, Santa Clara, CA 95054

Phone (408) 737-4600

Fax (408) 737-4611

brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.

Ordering Information

Voltage Package Marking1Part Number (Tape and Reel)2

3.0V SC70JW-8 AAT2265IJS-3.0-T1

3.3V SC70JW-8 ZIXYY AAT2265IJS-3.3-T1

3.6V SC70JW-8 AAT2265IJS-3.6-T1

5.0V SC70JW-8 AAT2265IJS-5.0-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

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Package Information

SC70JW-8

0.225

0.075

0.45

0.10

0.05

2.10

0.30

2.00

0.20

1.75

0.10

0.85

0.15

0.05

1.10 MAX

0.100

2.20

0.20

0.048REF

0.50 BSC 0.50 BSC 0.50 BSC

All dimensions in millimeters.

1. XYY = assembly and date code.

2. Sample stock is generally held on part numbers listed in BOLD. Other output voltages can be factory programmed in 100mV intervals from 2.5V to 5.0V. Contact your local

sales representative for availability and minimum order quantities.