AAT1230ITP-1-T1 - AnalogicTech - Datasheet.Directory

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

1230.2009.06.1.7 1

www.analogictech.com

General Description

The AAT1230/1230-1 is a high frequency, high efficiency

boost converter capable of 18V maximum output volt-

age. The internal power switch can deliver 100mA load

current. It is the ideal power solution to power OLED,

LCD, and CCD applications operating from a single cell

lithium-ion battery.

Hysteretic control provides up to 2MHz switching fre-

quency and fast response to load transients with small,

low-cost external components. The fully integrated con-

trol IC simplifies the design while reducing the total PCB

footprint. The AAT1230/1230-1 offers a true load discon-

nect feature which isolates the load from the power

source when EN/SET is pulled low. This eliminates leak-

age current and maintains zero voltage at the output

while disabled.

The output voltage can be dynamically set by activating

one of two reference levels (FB1 or FB2) through the SEL

logic pin. Optionally, AnalogicTech’s Simple Serial Control™

(S2Cwire™) single wire interface provides dynamic pro-

grammability across a wide output voltage range through

the EN/SET pin.

The AAT1230/1230-1 are available in a Pb-free, thermal-

ly-enhanced 16-pin 3x4mm TDFN low-profile package or

a Pb-free 12-pin TSOPJW package.

Features

• V

IN Range: 2.7V to 5.5V

• Maximum Output: 18V @ 100mA

• True Load Disconnect

• Dynamic Voltage Control Options

• Hysteretic Control

▪ No External Compensation Components

▪ Excellent Load Transient Response

▪ High Efficiency at Light Load

• Up to 2MHz Switching Frequency

• Ultra-Small Inductor and Capacitors

• Integrated Low RDS(ON) MOSFET Switches

• Up to 85% Efficiency

• <1μA Shutdown Current

• Integrated Soft Start

• Two Turn-On Time Options

▪ AAT1230: TSS = 0.35ms

▪ AAT1230-1: TSS = 3.5ms

• Cycle-by-Cycle Current Limit

• Short-Circuit, Over-Temperature Protection

• Available in TSOPJW-12 or TDFN34-16 Package

• -40°C to +85°C Temperature Range

Applications

• CCD Bias Circuit

• Digital Still Cameras

• LCD Bias Circuit

• Mobile Handsets

• MP3 Players

• OLED Displays

• PDAs and Notebook PCs

Typical Application

LIN

EN/SET

PGND

2.2μF

2.2μH

Schottky

78.7kΩ

562Ω

2.2μF, 25

4.99kΩ

Enable/Set

Select

AAT1230/

AAT1230-1

FB1

FB2

SEL

18V @ 100mA

VIN

GND

VBAT

3.6V

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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Pin Descriptions

Pin #

Symbol Function

TSOPJW-12 TDFN34-16

1 15, 16 VP Input power pin; connected to the source of the P-channel MOSFET. Connect to the

input capacitor(s).

2 14 EN/SET IC active high enable pin. Alternately, input pin for S2Cwire control utilizing FB2

reference.

3 13 SEL Logic high selects FB1 high output reference; logic low selects FB2 low output refer-

ence. Pull low for S2Cwire control.

4 12 VIN Input voltage for the converter. Connect this pin directly to the VP pin.

5 11 N/C No connection.

6, 7 9, 10 SW Boost converter switching node. Connect the power inductor between this pin and

LIN pin.

8 6, 7, 8 PGND Power ground for the boost converter; connected to the source of the N-channel

MOSFET. Connect to the input and output capacitor return.

9 5 GND Ground pin.

10 4 FB2 Feedback pin for low output voltage set point. Pin set to 0.6V when SEL is low and

disabled when SEL is high. Voltage is set from 0.6V to 1.2V with S2Cwire control.

11 3 FB1 Feedback pin for high output voltage set point. Pin set to 1.2V when SEL is high and

disabled when SEL is low. Disabled with S2Cwire control.

12 1, 2 LIN Switched power input. Connected to the power inductor.

N/A EP Exposed paddle (bottom). Tied to SW pins. May be connected to SW pins or left

ﬂ oating.

Pin Configuration

TSOPJW-12 TDFN34-16

(Top View) (Top View)

EN/SET

SEL

VIN

N/C

LIN

FB1

FB2

GND

PGND

FB1

FB2

GND

LIN

PGND

EN/SET

SEL

VIN

N/C

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

1230.2009.06.1.7 3

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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.

AAT1230/1230-1 Feature Options

Part Number Soft Start Time, TSS Package

AAT1230ITP 0.35ms TSOPJW-12

AAT1230IRN 0.35ms TDFN34-16

AAT1230ITP-1 3.5ms TSOPJW-12

Absolute Maximum Ratings1

TA = 25°C, unless otherwise noted.

Symbol Description Value Units

VIN Input Voltage -0.3 to 6.0 V

SW Switching Node 20 V

LIN, EN/SET, SEL,

FB1, FB2 Maximum Rating VIN + 0.3 V

TJOperating Temperature Range -40 to 150 °C

TSStorage Temperature Range -65 to 150 °C

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

Recommended Operating Conditions

Symbol Description Value Units

θJA Thermal Resistance TDFN34-16 44 °C/W

TSOPJW-12 160

PDMaximum Power Dissipation (TA = 25°C) TDFN34-16 2270 mW

TSOPJW-12 625

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

4 1230.2009.06.1.7

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1. The AAT1230/1230-1 is guaranteed to meet performance specifications from 0°C to 70°C. Specification over the -40°C to +85°C operating temperature range is assured by

design, characterization, and correlation with statistical process controls.

2. Total input current with prescribed FB resistor network can be reduced with larger resistor values.

Electrical Characteristics1

TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C, VIN = 3.6V.

Symbol Description Conditions Min Typ Max Units

Power Supply

VIN Input Voltage Range 2.7 5.5 V

VOUT(MAX) Maximum Output Voltage 18 V

VUVLO UVLO Threshold

VIN Rising 2.7 V

Hysteresis 150 mV

VIN Falling 1.8 V

IQQuiescent Current SEL = GND, VOUT = 14V, IOUT = 0, Switching22.0 mA

SEL = GND, FB2 = 1.5V, Not Switching 40 70 μA

ISHDN VIN Pin Shutdown Current EN/SET = GND 1.0 μA

IOUT Output Current 2.7V < VIN < 5.5V, VOUT = 18V 100 mA

FB1 FB1 Reference Voltage IOUT = 0 to 100mA, VIN = 2.7V to 5.0V, SEL = High 1.164 1.2 1.236 V

FB2 FB2 Reference Voltage IOUT = 0 to 100mA, VIN = 2.7V to 5.0V, SEL = Low 0.582 0.6 0.618 V

ΔVLOADREG Load Regulation IOUT = 0 to 100mA 0.01 %/mA

ΔVLINEREG/

ΔVIN

Line Regulation VIN = 2.7V to 5.5V 0.6 %/V

RDS(ON)L Low Side Switch On Resistance 0.06 Ω

RDS(ON)IN

Input Disconnect Switch On

Resistance 0.18 Ω

TSS Soft-Start Time From Enable to Output

Regulation; VOUT = 15V

AAT1230 0.35 ms

AAT1230-1 3.5 ms

TSD

Over-Temperature Shutdown

Threshold 140 °C

THYS Shutdown Hysteresis 15 °C

ILIM N-Channel Current Limit VIN = 3.6V 3.0 A

SEL, EN/SET

VSEL(L) SEL Threshold Low VIN = 2.7V 0.4 V

VSEL(H) SEL Threshold High VIN = 5.5V 1.4 V

VEN/SET(L) Enable Threshold Low VIN = 2.7V 0.4 V

VEN/SET(H) Enable Threshold High VIN = 5.5V 1.4 V

TEN/SET LO EN/SET Low Time 0.3 75 μs

TEN/SET HI MIN Minimum EN/SET High Time 50 ns

TEN/SET HI MAX Maximum EN/SET High Time 75 μs

TOFF EN/SET Off Timeout 500 μs

TLAT EN/SET Latch Timeout 500 μs

IEN/SET EN/SET Input Leakage -1 1 μA

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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Typical Characteristics

Efficiency vs. Load

(VOUT = 18V)

Output Current (mA)

Efficiency (%)

0.1 1 10 100

VIN = 5V

VIN = 4.2V VIN = 3.6V

DC Regulation

(VOUT = 18V)

Output Current (mA)

Output Error (%)

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

0.1 1 10 100

VIN = 5V

VIN = 4.2V

VIN = 3.6V

VIN = 2.7V

Efficiency vs. Load

(VOUT = 15V)

Output Current (mA)

Efficiency (%)

VIN = 5V

0.1 1 10 100

VIN = 4.2V VIN = 3.6V

DC Regulation

(VOUT = 15V)

Output Current (mA)

Output Error (%)

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

0.1 1 10 100

VIN = 5V

VIN = 4.2V

VIN = 3.6V

VIN = 2.7V

Efficiency vs. Load

(VOUT = 12V)

Output Current (mA)

Efficiency (%)

0.1 1 10 100

VIN = 5V

VIN = 4.2V VIN = 3.6V

DC Regulation

(VOUT = 12V)

Output Current (mA)

Output Error (%)

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

0.1 1 10 100

VIN = 5V

VIN = 4.2V

VIN = 3.6V

VIN = 2.7V

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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Typical Characteristics

Line Regulation

(VOUT = 18V)

Input Voltage (V)

Accuracy (%)

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

2.5 3 3.5 4 4.5 5 5.5 6

IOUT = 60mA

IOUT = 40mA

IOUT = 10µA

Output Voltage Error vs. Temperature

(VIN = 5V; VOUT = 18V; IOUT = 100mA)

Temperature (°

Output Error (%)

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

-40 -15 10 35 60 85

No Load Input Current vs. Input Voltage

(VOUT = 18V; EN = High)

Input Voltage (V)

Supply Current (mA)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

2.5 3 3.5 4 4.5 5 5.5 6

No Load Input Current vs. Temperature

(VIN = 3.6V; VOUT = 18V)

Temperature (°

Supply Current (mA)

1.62

1.64

1.66

1.68

1.70

1.72

1.74

1.76

1.78

-40 -15 10 35 60 85

Output Ripple

(VIN = 4.2V; VOUT = 18V; IOUT = 100mA)

Output Voltage

(top) (V)

Inductor Current

(bottom) (A)

Time (500ns/div)

17.0

17.2

17.4

17.6

17.8

18.0

18.2

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

Output Ripple

(VIN = 3.6V; No Load; VOUT = 12V)

Output Voltage

(top) (V)

Inductor Current

(bottom) (A)

Time (500µs/div)

11.0

11.2

11.4

11.6

11.8

12.0

12.2

-0.1

0.1

0.2

0.3

0.4

0.5

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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Typical Characteristics

Load Transient Response

(VIN = 4.2V; IOUT = 20mA–60mA; VOUT = 18V)

Output Voltage (V) (top)

Inductor Current (A) (bottom)

Time (200µs/div)

17.80

17.85

17.90

17.95

18.00

18.05

18.10

-0.3

0.0

0.3

0.6

0.9

1.2

1.5

Load Transient Response

(VIN = 3.6V; IOUT = 20mA–60mA; VOUT = 12V)

Output Voltage (V) (top)

Inductor Current (A) (bottom)

Time (200µs/div)

11.80

11.85

11.90

11.95

12.00

12.05

12.10

-0.30

0.00

0.30

0.60

0.90

1.20

1.50

P-Channel RDS(ON) vs. Input Voltage

Input Voltage (V)

RDS(ON) (mΩ

)

100

120

140

160

180

200

220

240

260

280

300

2.5 3 3.5 4 4.5 5 5.5 6

120°C100°C

85°C

25°C

N-Channel RDS(ON) vs. Input Voltage

Input Voltage (V)

RDS(ON) (mΩ

)

100

110

2.5 3 3.5 4 4.5 5 5.5 6

120°C100°C

85°C

25°C

AAT1230 Soft Start

(VIN = 3.6V; CIN = 2.2µF; IOUT = 100mA; VOUT = 12V)

Enable Voltage (middle) (V)

Output Voltage (top) (V)

Input Current

(bottom) (A)

Time (200µs/div)

-16

-12

-8

-4

-0.4

0.0

0.4

0.8

1.2

1.6

2.0

2.4

2.8

AAT1230-1 Soft Start

(VIN = 3.6V; CIN = 2.2µF; IOUT = 100mA; VOUT = 18V)

Enable Voltage (middle) (V)

Output Voltage (top) (V)

Input Current

(bottom) (A)

Time (1ms/div)

-20

-15

-10

-5

-0.2

0.0

0.4

0.8

1.2

1.6

2.0

2.4

2.8

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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Functional Description

The AAT1230/1230-1 consists of a DC/DC boost control-

ler, an integrated slew rate controlled input disconnect

MOSFET switch, and a MOSFET power switch. A high

voltage rectifier, power inductor, output capacitor, and

resistor divider network are required to implement a DC/

DC boost converter.

Control Loop

The AAT1230/1230-1 provides the benefits of current

mode control with a simple hysteretic feedback loop. The

device maintains exceptional DC regulation, transient

response, and cycle-by-cycle current limit without addi-

tional compensation components.

The AAT1230/1230-1 modulates the power MOSFET

switching current in response to changes in output volt-

age. This allows the voltage loop to directly program the

required inductor current in response to changes in the

output load.

The switching cycle initiates when the N-channel MOSFET

is turned ON and current ramps up in the inductor. The

ON interval is terminated when the inductor current

reaches the programmed peak current level. During the

OFF interval, the input current decays until the lower

threshold, or zero inductor current, is reached. The lower

current is equal to the peak current minus a preset hys-

teresis threshold - which determines the inductor ripple

current. The peak current is adjusted by the controller

until the output current requirement is met.

The magnitude of the feedback error signal determines

the average input current. Therefore, the AAT1230/1230-

1 controller implements a programmed current source

connected to the output capacitor and load resistor.

Functional Block Diagram

Control

VREF1

Output

Soft-Start

Timer

Select

FB1

FB2

SEL

EN/SET

VP LIN

VIN

PGND

GND

VREF2

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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There is no right-half plane zero, and loop stability is

achieved with no additional compensation components.

Increased load current results in a drop in the output

feedback voltage (FB1 or FB2) sensed through the feed-

back resistors (R1, R2, R3). The controller responds by

increasing the peak inductor current, resulting in higher

average current in the inductor. Alternatively, decreased

output load results in an increase in the output feedback

voltage (FB1 or FB2 pin). The controller responds by

decreasing the peak inductor current, resulting in lower

average current in the inductor.

At light load, the inductor OFF interval current goes

below zero and the boost converter enters discontinuous

mode operation. Further reduction in the load results in

a corresponding reduction in the switching frequency.

The AAT1230/1230-1 provide pulsed frequency opera-

tion which reduces switching losses and maintains high

efficiency at light loads.

Operating frequency varies with changes in the input

voltage, output voltage, and inductor size. Once the

boost converter has reached continuous mode, further

increases in the output load will not significantly change

the operating frequency. A small 2.2μH (±20%) inductor

is selected to maintain high frequency switching (up to

2MHz) and high efficiency operation for outputs from

10V to 18V.

Output Voltage Programming

The output voltage may be programmed through a resis-

tor divider network located from output capacitor to FB1/

FB2 pins to ground. Pulling the SEL pin high activates the

FB1 pin which maintains a 1.2V reference voltage, while

the FB2 reference is disabled. Pulling the SEL pin low

activates the FB2 pin which maintains a 0.6V reference,

while the FB1 reference is disabled. This function allows

dynamic selection between two distinct output voltages

across a 2X range (maximum). An additional resistor

between FB1 and FB2 allows the designer to program the

outputs across a reduced <2X range.

Alternatively, the output voltage may be dynamically

programmed to any of 16 voltage levels using the

S2Cwire serial digital input. The single wire S2Cwire inter-

face provides high-speed output voltage programmabil-

ity across a 2X output voltage range. S2Cwire functional-

ity is enabled by pulling the SEL pin low and providing

S2Cwire digital clock input to the EN/SET pin. Table 2

details the FB2 reference voltage versus S2Cwire rising

clock edges.

Soft Start / Enable

The input disconnect switch is activated when a valid

input voltage is present and the EN/SET pin is pulled

high. The slew rate control on the P-channel MOSFET

ensures minimal inrush current as the output voltage is

charged to the input voltage, prior to switching of the

N-channel power MOSFET. Monotonic turn-on is guaran-

teed by the built-in soft-start circuitry. Soft-start elimi-

nates output voltage overshoot across the full input

voltage range and all loading conditions.

Fast and slow start-up time options are available. The

AAT1230 provides start-up to regulated output voltage

within 0.35ms of a low-to-high transition on the EN/SET

pin. Alternatively, the AAT1230-1 provides start-up to

regulated output voltage within 3.5ms of a low-to-high

transition on the EN/SET pin, which dramatically reduces

inrush current. A longer soft-start, or turn-on, time is a

preferred feature in battery-powered systems that

exhibit higher source impedances.

Some applications may require the output to be active

when a valid input voltage is present. In these cases,

add a 10kΩ resistor between the VIN, VP, and EN/SET

pins to avoid startup issues.

Current Limit and

Over-Temperature Protection

The switching of the N-channel MOSFET terminates

when current limit of 3.0A (typical) is exceeded. This

minimizes power dissipation and component stresses

under overload and short-circuit conditions. Switching

resumes when the current decays below the current

limit.

Thermal protection disables the AAT1230/1230-1 when

internal dissipation becomes excessive. Thermal protec-

tion disables both MOSFETs. The junction over-tempera-

ture threshold is 140°C with -15°C of temperature hys-

teresis. The output voltage automatically recovers when

the over-temperature or over-current fault condition is

removed.

Under-Voltage Lockout

Internal bias of all circuits is controlled via the VIN input.

Under-voltage lockout (UVLO) guarantees sufficient VIN

bias and proper operation of all internal circuitry prior to

soft start.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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Application Information

Selecting the Output Diode

To ensure minimum forward voltage drop and no recov-

ery, high voltage Schottky diodes are considered the

best choice for the AAT1230/1230-1 boost converter.

The AAT1230/1230-1 output diode is sized to maintain

acceptable efficiency and reasonable operating junction

temperature under full load operating conditions. Forward

voltage (VF) and package thermal resistance (θJA) are the

dominant factors to consider in selecting a diode. The

diode’s published current rating may not reflect actual

operating conditions and should be used only as a com-

parative measure between similarly rated devices. 20V

rated Schottky diodes are recommended for outputs less

than 15V, while 30V rated Schottky diodes are recom-

mended for outputs greater than 15V.

The switching period is divided between ON and OFF

time intervals.

= TON + TOFF

During the ON time, the N-channel power MOSFET is

conducting and storing energy in the boost inductor.

During the OFF time, the N-channel power MOSFET is

not conducting. Stored energy is transferred from the

input battery and boost inductor to the output load

through the output diode. Duty cycle is defined as the

ON time divided by the total switching interval.

+ T

OFF

D =

= T

⋅ F

The maximum duty cycle can be estimated from the

relationship for a continuous mode boost converter.

Maximum duty cycle (DMAX) is the duty cycle at minimum

input voltage (VIN(MIN)).

OUT

+ V

- V

IN(MIN)

)

OUT

+ V

)

MAX

The average diode current during the OFF time can be

estimated.

OUT

1 - D

MAX

AVG(OFF)

The following curves show the VF characteristics for dif-

ferent Schottky diodes (100°C case). The VF of the

Schottky diode can be estimated from the average cur-

rent during the off time.

LIN 12

FB1 11

FB2 10

GND 9

PGND 8

SW 7

6N/C

5VIN

4SEL

3EN/SET

2VP

JP1

JP2

VIN

U1 AAT1230/1230-1 TSOPJW12

C1 10V 0603 2.2μF

C2 25V 0805 2.2μF

D1 30V 0.5A MBR0530T1 SOD-123

L1 2.2μH SD3814-2R2

R1 78.7k 0603

R2 562 0603

R3 4.99k 0603

R4 10k 0603

2.2μH

Schottky

78.7k

2.2μF

VOUT

562

4.99k

10K

Select

Enable

Figure 1: AAT1230/1230-1 Demo Board Schematic.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

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Forward Voltage (V)

Forward Current (mA)

100

1000

10000

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70

B340LA

MBR0530

ZHCS350

BAT42W

The average diode current is equal to the output cur-

rent.

IAVG(TOT) = IOUT

The average output current multiplied by the forward

diode voltage determines the loss of the output diode.

PLOSS(DIODE) = IAVG(TOT) · VF

= IOUT · VF

Diode junction temperature can be estimated.

TJ(DIODE) = TAMB + ΘJA · PLOSS(DIODE)

Output diode junction temperature should be maintained

below 110ºC, but may vary depending on application

and/or system guidelines. The diode θJA can be mini-

mized with additional PCB area on the cathode. PCB

heatsinking the anode may degrade EMI performance.

The reverse leakage current of the rectifier must be con-

sidered to maintain low quiescent (input) current and

high efficiency under light load. The rectifier reverse cur-

rent increases dramatically at high temperatures.

Selecting the Boost Inductor

The AAT1230/1230-1 controller utilizes hysteretic con-

trol and the switching frequency varies with output load

and input voltage. The value of the inductor determines

the maximum switching frequency of the AAT1230/1230-

1 boost converter. Increased output inductance decreas-

es the switching frequency, resulting in higher peak cur-

rents and increased output voltage ripple. To maintain

2MHz maximum switching frequency and stable opera-

tion, an output inductor sized from 1.5μH to 2.7μH is

recommended.

A better estimate of DMAX is possible when VF is known.

OUT

+ V

- V

IN(MIN)

)

OUT

+ V

)

MAX

Where VF is the Schottky diode forward voltage. If not

known, it can be estimated at 0.5V. Manufacturer’s spec-

ifications list both the inductor DC current rating, which

is a thermal limitation, and peak inductor current rating,

which is determined by the saturation characteristics.

Measurements at full load and high ambient temperature

should be completed to ensure that the inductor does not

saturate or exhibit excessive temperature rise.

The output inductor (L) is selected to avoid saturation at

minimum input voltage, maximum output load condi-

tions. Peak current may be estimated using the following

equation, assuming continuous conduction mode. Worst-

case peak current occurs at minimum input voltage

(maximum duty cycle) and maximum load. Switching

frequency can be estimated from the curves and assumes

a 2.2μH inductor.

Output Current (mA)

Switching Frequency (MHz)

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

40 50 60 70 80 90 100

VIN = 2.7V

VOUT = 15V

VIN = 2.7V

VOUT = 18V

VIN = 3.0V

VOUT = 15V

VIN = 3.0V

VOUT = 18V

VIN = 3.6V

VOUT = 15V

VIN = 3.6V

VOUT = 18V

Output Current (mA)

Switching Frequency (MHz)

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

40 50 60 70 80 90 100

VIN = 3.6V

VOUT = 10V

VIN = 3.6V

VOUT = 12V

VIN = 2.7V

VOUT = 12V

VIN = 2.7V

VOUT = 10V

VIN = 3.0V

VOUT = 10V

VIN = 3.0V

VOUT = 12V

OUT

(1 - D

MAX

)

MAX

IN(MIN)

PEAK

= +

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

12 1230.2009.06.1.7

www.analogictech.com

At light load and low output voltage, the controller

reduces the operating frequency to maintain maximum

operating efficiency. As a result, further reduction in out-

put load does not reduce the peak current. Minimum

peak current can be estimated from 0.5A to 0.75A.

The RMS current flowing through the boost inductor is

equal to the DC plus AC ripple components. Under worst-

case RMS conditions, the current waveform is critically

continuous. The resulting RMS calculation yields worst-

case inductor loss. The RMS current value should be

compared against the manufacturer’s temperature rise,

or thermal derating, guidelines.

PEAK

RMS

For a given inductor type, smaller inductor size leads to

an increase in DCR winding resistance and, in most

cases, increased thermal impedance. Winding resistance

degrades boost converter efficiency and increases the

inductor’s operating temperature.

PLOSS(INDUCTOR) = IRMS2 · DCR

To ensure high reliability, the inductor temperature

should not exceed 100ºC. In some cases, PCB heatsink-

ing applied to the AAT1230/1230-1 LIN node (non-switch-

ing) can improve the inductor’s thermal capability. PCB

heatsinking may degrade EMI performance when applied

to the SW node (switching) of the AAT1230/1230-1.

Shielded inductors provide decreased EMI and may be

required in noise sensitive applications. Unshielded chip

inductors provide significant space savings at a reduced

cost compared to shielded (wound and gapped) induc-

tors. In general, chip-type inductors have increased

winding resistance (DCR) when compared to shielded,

wound varieties.

Selecting the Boost Capacitors

The high output ripple inherent in the boost converter

necessitates low impedance output filtering. Multi-layer

ceramic (MLC) capacitors provide small size and ade-

quate capacitance, low parasitic equivalent series resis-

tance (ESR) and equivalent series inductance (ESL), and

are well suited for use with the AAT1230/1230-1 boost

regulator. MLC capacitors of type X7R or X5R are recom-

mended to ensure good capacitance stability over the full

operating temperature range.

The output capacitor is sized to maintain the output load

without significant voltage droop (ΔVOUT) during the

power switch ON interval, when the output diode is not

conducting. A ceramic output capacitor from 2.2μF to

4.7μF is recommended. Typically, 25V rated capacitors

are required for the 18V boost output. Ceramic capaci-

tors sized as small as 0805 are available which meet

these requirements.

MLC capacitors exhibit significant capacitance reduction

with applied voltage. Output ripple measurements should

confirm that output voltage droop is acceptable. Voltage

derating can minimize this factor, but results may vary

with package size and among specific manufacturers.

Output capacitor size can be estimated at a switching

frequency (FSW) of 500kHz (worst-case).

OUT

· D

MAX

· ΔV

OUT

The boost converter input current flows during both ON

and OFF switching intervals. The input ripple current is

less than the output ripple and, as a result, less input

capacitance is required. A ceramic output capacitor from

1μF to 3.3μF is recommended. Minimum 6.3V rated

ceramic capacitors are required at the input. Ceramic

capacitors sized as small as 0603 are available which

meet these requirements.

The AAT1230/1230-1 provides excellent load transient

response, but large capacitance tantalum or solid-electro-

lytic capacitors may be desired. These can replace (or be

used in parallel with) ceramic capacitors. Both tantalum

and OSCON-type capacitors are suitable due to their low

ESR and excellent temperature stability (although they

exhibit much higher ESR than MLC capacitors). Aluminum-

electrolytic types are less suitable due to their high ESR

characteristics and temperature drift. Unlike MLC capaci-

tors, these types are polarized and proper orientation on

input and output pins is required. 30% to 70% voltage

derating is recommended for tantalum capacitors.

Setting the Output Voltage

The output voltage may be programmed through a resis-

tor divider network located from the output to FB1 and

FB2 pins to ground. Pulling the SEL pin high activates the

FB1 pin which maintains a 1.2V reference voltage, while

the FB2 reference is disabled. Pulling the SEL pin low

activates the FB2 pin which maintains a 0.6V reference,

while the FB1 reference is disabled.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

1230.2009.06.1.7 13

www.analogictech.com

The AAT1230/1230-1 output voltage can be programmed

by one of three methods. First, the output voltage can

be static by pulling the SEL logic pin either high or low.

Second, the output voltage can be dynamically adjusted

between two pre-set levels within a 2X operating range

by toggling the SEL logic pin. Third, the output can be

dynamically adjusted to any of 16 preset levels within a

2X operating range using the integrated S2Cwire single

wire interface via the EN/SET pin.

Option 1: Static Output Voltage

A static output voltage can be configured by pulling the

SEL either high or low. SEL pin high activates the FB1

reference pin to 1.2V (nominal). Alternatively, the SEL

pin is pulled low to activate the FB2 reference at 0.6V

(nominal). Table 1 provides details of resistor values for

common output voltages from 10V to 18V for SEL = High

and SEL = Low options.

In the static configuration, the FB1 pin should be directly

connected to FB2. The resistor between FB1 and FB2 pins

is not required. See Table 1 for static output voltages with

SEL = High or SEL = Low. SEL = High corresponds to

VOUT(1) and SEL = Low corresponds to VOUT(2).

Option 2: Dynamic Voltage

Control Using SEL Pin

The output may be dynamically adjusted between two

output voltages by toggling the SEL logic pin. Output

voltages VOUT(1) and VOUT(2) correspond to the two output

references, FB1 and FB2. Pulling the SEL logic pin high

activates VOUT(1), while pulling the SEL logic pin low acti-

vates VOUT(2).

The minimum output voltage must be greater than the

specified maximum input voltage plus margin to main-

tain proper operation of the AAT1230/1230-1 boost con-

verter. In addition, the ratio of output voltages VOUT(2)/

VOUT(1) is always less than 2.0, corresponding to a 2X

(maximum) programmable range.

See Table 1 for dynamic output voltage settings when

toggling between SEL = High and SEL = Low. SEL = High

corresponds to VOUT(1) and SEL = Low corresponds to

VOUT(2).

VOUT(1)

(SEL = High)

VOUT(2)

(SEL = Low)

R3 = 4.99kΩ

R1 (kΩ) R2 (kΩ)

10.0V – 36.5 0

12.0V – 44.2 0

15.0V – 57.6 0

16.0V – 61.9 0

18.0V – 69.8 0

– 10.0V 78.7 0

– 12.0V 95.3 0

– 15.0V 121 0

– 16.0V 127 0

– 18.0V 143 0

12.0V 10.0V 75 3.32

15.0V 10.0V 76.8 1.65

16.0V 10.0V 76.8 1.24

18.0V 10.0V 78.7 0.562

15.0V 12.0V 90.9 3.01

16.0V 12.0V 93.1 2.49

18.0V 12.0V 93.1 1.65

18.0V 15.0V 115 3.32

Table 1: SEL Pin Voltage Control Resistor Values

(1% resistor tolerance).

Option 3: Dynamic Voltage

Control Using S2Cwire Interface

The output can be dynamically adjusted by the host con-

troller to any of 16 pre-set output voltage levels using

the integrated S2Cwire interface. The EN/SET pin serves

as the S2Cwire interface input. The SEL pin must be

pulled low when using the S2Cwire interface.

S2Cwire Serial Interface

AnalogicTech’s S2Cwire serial interface is a proprietary

high-speed single-wire interface available only from

AnalogicTech. The S2Cwire interface records rising edges

of the EN/SET input and decodes into 16 different states.

Each state corresponds to a voltage setting on the FB2

pin, as shown in Table 2.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

14 1230.2009.06.1.7

www.analogictech.com

S2Cwire Serial Interface Timing

The S2Cwire serial interface has flexible timing. Data can

be clocked-in at speeds up to 1MHz. After data has been

submitted, EN/SET is held high to latch the data for a

period TLAT

. The output is subsequently changed to the

predetermined voltage. When EN/SET is set low for a

time greater than TOFF

, the AAT1230/1230-1 is disabled.

When disabled, the register is reset to the default value,

which sets the FB2 pin to 0.6V if EN is subsequently

pulled high.

S2Cwire Output Voltage Programming

The AAT1230/1230-1 is programmed through the S2Cwire

interface according to Table 2. The rising clock edges

received through the EN/SET pin determine the feedback

reference and output voltage set-point. Upon power up

with the SEL pin low and prior to S2Cwire programming,

the default feedback reference voltage is set to 0.6V.

EN/SET

Rising

Edges

FB2

Reference

Voltage (V)

EN/SET

Rising

Edges

FB2

Reference

Voltage (V)

1 0.60 (Default) 9 0.92

2 0.64 10 0.96

3 0.68 11 1.00

4 0.72 12 1.04

5 0.76 13 1.08

6 0.80 14 1.12

7 0.84 15 1.16

8 0.88 16 1.20

Table 2: S2Cwire Voltage Control Settings

(SEL = Low).

PCB Layout Guidelines

Boost converter performance can be adversely affected

by poor layout. Possible impact includes high input and

output voltage ripple, poor EMI performance, and reduced

operating efficiency. Every attempt should be made to

optimize the layout in order to minimize parasitic PCB

effects (stray resistance, capacitance, inductance) and

EMI coupling from the high frequency SW node.

A suggested PCB layout for the AAT1230/1230-1 boost

converter is shown in Figures 3 and 4. The following PCB

layout guidelines should be considered:

1. Minimize the distance from Capacitor C1 and C2

negative terminal to the PGND pins. This is espe-

cially true with output capacitor C2, which conducts

high ripple current from the output diode back to the

PGND pins.

2. Place the feedback resistors close to the output ter-

minals. Route the output pin directly to resistor R1 to

maintain good output regulation. R3 should be routed

close to the output GND pin, but should not share a

significant return path with output capacitor C2.

3. Minimize the distance between L1 to D1 and switch-

ing pin SW; minimize the size of the PCB area con-

nected to the SW pin.

4. Maintain a ground plane and connect to the IC RTN

pin(s) as well as the GND terminals of C1 and C2.

5. Consider additional PCB area on D1 cathode to

maximize heatsinking capability. This may be neces-

sary when using a diode with a high VF and/or ther-

mal resistance.

6. When using the TDFN33-12 package, connect paddle

to SW pin or leave floating. Do not connect to RTN/

GND conductors.

7. To avoid problems at startup, add a 10kΩ resistor

between the VIN, VP and EN/SET pins (R4). This is

critical in applications requiring immunity from input

noise during “hot plug” events, e.g. when plugged

into an active USB port.

EN/SET

2n-1 n ≤ 16

Data Reg 0n-1

THI

TLO TLAT TOFF

Figure 2: S2Cwire Timing Diagram to Program the Output Voltage.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

1230.2009.06.1.7 15

www.analogictech.com

Figure 3: AAT1230/1230-1 Evaluation Figure 4: AAT1230/1230-1 Evaluation

Board Top Side. Board Bottom Side.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

16 1230.2009.06.1.7

www.analogictech.com

Boost Converter Design Example

Specification

VOUT = 16V

IOUT = 100mA

VIN = 2.7V to 4.2V (3.6V nominal)

TAMB = 50°C

Schottky Diode

MAX

= = = 0.831

- V

IN(MIN)

16 - 2.7

2.7

OFF(DIODE)

= = = 0.592A = 592mA

OUT

1 - D

MAX

0.1A

1 - 0.831

For Schottky diode MBR0530, VF  0.32 @ 600mA, θJA  206°C/W in SOD-123 package.

PLOSS(DIODE) = IOUT · VF = (0.1A)(0.32V) = 0.032W = 32mW

TJ(DIODE) = TAMB + θJA · PLOSS(DIODE)

= 50 + 206 · (0.032)

= 50 + 6.6

= 56.6°C

16V Output Inductor

OUT

+ V

- V

IN(MIN)

OUT

+ V

MAX

16 + 0.32 - 2.7

16 + 0.32

= = 0.834

From Switching Frequency vs. IOUT curves estimated switching frequency of AAT1230/1230-1 with VOUT = 16V and IOUT

= 100mA, FSW = 800kHz.

OUT

1 - D

MAX

IN(MIN)

PEAK

= +

0.100

1 - 0.840

0.834 (2.7V)

0.8M

2.2µH

= 0.625 + 0.640

PEAK

RMS

= = = 730m

1265

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

1230.2009.06.1.7 17

www.analogictech.com

For Coiltronics inductor SD3814-2R2, ISAT = 1.90A, IRMS(MAX) = 1.43A and DCR = 77mΩ.

PLOSS(INDUCTOR) = IRMS2 · DCR

= (0.730)2 (0.077)

= 0.041W

= 41mW

16V Output Capacitor

OUT

· D

MAX

· ΔV

OUT

= 1.05µF; use 2.2µF/25V MLC

ΔV

OUT

= 0.1V

=(0.1A) (0.84)

(0.8kHz) (0.1V)

AAT1230/1230-1 Losses

IRMS(ON) = IPEAK · DMAX

= 1.270

= 0.527A

= 527mA

0.834

IRMS(OFF) = IPEAK · (1 - DMAX)

= 1.270

= 0.298A

= 298mA

0.166

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

18 1230.2009.06.1.7

www.analogictech.com

From datasheet curves, VIN = 3.6V, TCASE = 100°C, TSOPJW-12:

RDS(ON)L = 75mΩ, RDS(ON)IN = 220mΩ, θJA = 160°C/W.

PLOSS(RDSON) = IRMS(ON)2 · (RDS(ON)L + RDS(ON)IN) + IRMS(OFF)2 · RDS(ON)IN

= 0.5272 (0.220 + 0.075) + 0.2982 · 0.075

= 0.082 + 0.007

= 89mW

TJ(MAX) = TAMB + θJA · PLOSS(RDSON)

= 50 + 160 (0.089)

= 50 + 14.2

= 64.2°C

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

1230.2009.06.1.7 19

www.analogictech.com

1. Results may vary depending on test method used and specific manufacturer.

Manufacturer Part Number

Rated IF(AV)

Current (A)1

Rated Voltage

(V)

Thermal Resistance

(ΘJA, °C/W)1Case

Diodes, Inc.

B340LA 3.00 40 25 SMA

SD103AWS 0.35 30 625 SOD-323

BAT42WS 0.20 30 625 SOD-323

B0520WS 0.50 20 426 SOD-323

ON Semi MBR130LSFT 1.00 30 325 SOD-123

MBR0530T 0.50 30 206 SOD-123

Zetex ZHCS350 0.35 40 330 SOD-523

BAT54 0.20 30 330 SOT-23

Table 3: Typical Surface Mount Schottky Rectifiers for Various Output Loads.

(select TJ < 110°C in application circuit).

Manufacturer Part Number Inductance (μH)

Max DC ISAT

Current (A) DCR (Ω)

Size (mm)

LxWxH Type

Sumida CDR4D11/HP-2R4 2.4 1.70 105 4.8x4.8x1.2 Shielded

Sumida CDRH4D18-2R2 2.2 1.32 75 5.0x5.0x2.0 Shielded

Murata LQH55DN2R2M03 2.2 3.20 29 5.0x5.7x4.7 Non-Shielded

Murata LQY33PN2R2M02 2.2 0.72 360 3.2x3.2x0.85 Non-Shielded

Taiyo Yuden NR40182R2 2.2 2.70 60 4.0x4.0x1.8 Shielded

Taiyo Yuden NR30152R2 2.2 1.48 60 3.0x3.0x1.5 Shielded

Taiyo Yuden NR40102R2 2.2 1.15 150 4.0x4.0x1.0 Shielded

Taiyo Yuden CBC3225T2R2MR 2.2 1.13 80 3.2x2.5x2.5 Non-Shielded

Coiltronics SD3814-2R2 2.2 1.90 77 3.8x3.8x1.4 Shielded

Coiltronics SD3114-2R2 2.2 1.48 86 3.1x3.1x1.4 Shielded

Coiltronics SD3112-2R2 2.2 1.12 140 3.1x3.1x1.2 Shielded

Table 4: Typical Surface Mount Inductors for Various Output Loads

(select IPEAK < ISAT).

Manufacturer Part Number Type Value (μF) Voltage (V) Temp. Co.

Footprint

LxWxH (mm)

Murata GRM188R60J475KE19D Ceramic 2.2 6.3 X5R 0603

Murata GRM188R61A225KE34D Ceramic 2.2 10 X5R 0603

Murata GRM188R61C225KA88 Ceramic 2.2 16 X5R 0805

Murata GRM21BR61E225KA12L Ceramic 2.2 25 X5R 0805

Murata GRM188R61E105KA12D Ceramic 1.0 25 X5R 0603

Table 5: Typical Surface Mount Capacitors for Various Output Loads.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

20 1230.2009.06.1.7

www.analogictech.com

1. XYY = assembly and date code.

2. Sample stock is generally held on part numbers listed in BOLD.

3. 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.

Ordering Information

Package Marking1Part Number (Tape and Reel)2

TSOPJW-12 RDXYY AAT1230ITP-T1

TDFN34-16 RDXYY AAT1230IRN-T1

TSOPJW-12 TJXYY AAT1230ITP-1-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/about/quality.aspx.

Package Information3

TSOPJW-12

0.20 + 0.10

- 0.05

0.055 ± 0.045 0.45 ± 0.15

7° NOM

4° ± 4°

3.00 ± 0.10

2.40 ± 0.10

2.85 ± 0.20

0.50 BSC 0.50 BSC 0.50 BSC 0.50 BSC 0.50 BSC

0.15 ± 0.05

0.9625

0.0375

1.00 + 0.10

- 0.065

0.04 REF

0.010

2.75 ± 0.25

All dimensions in millimeters.

AAT1230

18V 100mA Step-Up ConverterSwitchRegTM

PRODUCT DATASHEET

1230.2009.06.1.7 21

www.analogictech.com

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.

TDFN34-16

3.000

0.050 1.600

0.050

0.050 0.229

0.051

(4x)

0.850 MAX

4.000

0.050

3.300

0.050

Index Area

Detail "A"

Top View Bottom View

Side View

0.350

0.100

0.230

0.0500.450

0.050

Detail "A"

Pin 1 Indicator

(optional)

C0.3

All dimensions in millimeters.