AAT3174IWP-T1 - Skyworks Solutions, Inc.

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Typical Application

AAT3174

1μF

COUT

2.2μF

CIN

4.7μF

EN/SET

VIN

C1+ C1- C2+ C2-

OUT

VIN

(2.7V to 5.5V)

Enable or

S2Cwire

Flash

LED

GND

RSET

General Description

The AAT3174 is a high output current, high efficiency,

low noise, low profile charge pump DC/DC converter. The

device is ideal for multi-functional LED photo-flash appli-

cations where solution cost, size, and efficiency are

critical.

The AAT3174 is capable of driving a regulated output

current up to 800mA. Output current levels can be eas-

ily programmed in 16 steps through Skyworks’ Simple

Serial Control™ (S2Cwire™) interface controlled by a

single microcontroller GPIO line. This allows smooth

transitions and flexible adjustment of brightness in flash

or other lighting modes. The maximum output current

can also be set with an external RSET resistor.

The tri-mode (1X/1.5X/2X) operation of the internal

charge pump offers excellent power efficiency through-

out the output current range for both flash and movie

modes. Combined with a low external parts count (two

1μF flying capacitors and two small bypass capacitors at

VIN and OUT), the AAT3174 is ideally suited for small

battery-powered applications.

The AAT3174 has a thermal management system to pro-

tect the device in the event of a short-circuit condition at

the output pin. Built-in soft-start circuitry prevents

excessive inrush current during start-up. The shutdown

feature disconnects the load from VIN and reduces quies-

cent current to less than 1μA.

The AAT3174 is available in a Pb-free, thermally-enhanced

12-pin 3x3mm TDFN package and is specified over the

-40°C to +85°C temperature range.

Features

• Up to 800mA Output Current

• Tri-Mode 1X/1.5X/2X in Current Mode

• 16 Current Steps Set by S2Cwire

• External RSET to Set Maximum Current

• <1μA of Shutdown

• Small Application Circuit

• No Inductors

• Automatic Soft Start

• 12-Pin TDFN 3x3mm Package

• -40°C to +85°C Temperature Range

Applications

• Camcorders

• Camera Phones

• Digital Still Cameras

• PDAs and Notebook PCs

• Smart Phones

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

2Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Pin Descriptions

Pin # Symbol Function

1 VIN Input power supply pin. Requires 4.7μF bypass capacitor to ground.

2 C1+ Flying capacitor C1 positive terminal. Connect a 1μF capacitor between C1+ and C1-.

3 C1- Flying capacitor C1 negative terminal.

4 GND Ground connection.

5 FL Controlled current sink. Connect the ﬂ ash LED cathode to this pin.

6 RSET Connect resistor here to set maximum output current.

7 EN/SET

Charge pump enable / set input control pin. When in the low state, the AAT3174 is powered down and

consumes less than 1μA. When connected to logic high level, the AAT3174 charge pump is active. This

pin should not be left ﬂ oating.

8 N/C Not connected.

9 C2- Flying capacitor C2 negative terminal.

10 C2+ Flying capacitor C2 positive terminal. Connect a 1μF capacitor between C2+ and C2-.

11 OUT Charge pump output. Requires 2.2μF bypass capacitor to ground. Connect to ﬂ ash LED anode to drive

the LED.

12 VIN Input power supply pin. Requires 4.7μF bypass capacitor to ground.

EP Exposed paddle (bottom). Connect to GND directly beneath package.

Pin Configuration

TDFN33-12

(Top View)

VIN

C1+

C1-

GND

RSET

VIN

OUT

C2+

C2-

N/C

EN/SE

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

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 an FR4 board.

Absolute Maximum Ratings1

TA = 25°C, unless otherwise noted.

Symbol Description Value Units

VIN Input Voltage -0.3 to 6.0 V

VEN EN to GND Voltage -0.3 to 6.0 V

VEN(MAX) Maximum EN to Input Voltage VIN + 0.3 V

IOUT Maximum Output Current 1000 mA

TJOperating Temperature Range -40 to 150 °C

TSStorage Temperature Range -65 to 150 °C

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

Thermal Information2

Symbol Description Value Units

JA Thermal Resistance 50 °C/W

PDMaximum Power Dissipation 2.0 mW

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

4Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

1. The AAT3174 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. Mounted on an FR4 board.

Electrical Characteristics1

CIN = 4.7μF, C OUT = 2.2μF, C 1 = C2 = 1.0μF; 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

ICC Operating Current

1X, No Load Current 300

μA3.0 ≤ VIN ≤ 5.5, 1.5X Mode, No Load Current 2.0 4.0

3.0 ≤ VIN ≤ 5.5, 2X Mode, No Load Current 3.0 6.0

ISHDN(MAX) VIN Pin Shutdown Current EN = 0 1.0 μA

IOUT(MAX)2Maximum Output Current VF = 3.6V 800 mA

IDX Output Current Accuracy Programmed for 600mA; RSET = 187k540 660 mA

TSS Soft-Start Time 200 μs

VRSET RSET Pin Voltage 0.7 V

EN/SET

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

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

TEN/SET LO EN/SET Low Time 0.3 60 μs

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

TEN/SET HI MAX Maximum EN/SET High Time 60 μs

TOFF EN/SET Off Timeout 500 μs

TLAT EN/SET Latch Timeout 500 μs

Input Current EN/SET Input Leakage -1 1 μA

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Typical Characteristics

VIN = 3.6V, CIN = 4.7μF, C OUT = 2.2μF, C 1 = C2 = 1μF, TA = 25°C, unless otherwise noted.

Efficiency vs. Supply Voltage

Supply Voltage (V)

Efficiency (%)

100

2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2

ILED = 300mA

ILED = 150mA

Turn-On to 1X Mode

(VIN = 4.2V; ILED = 150mA)

Time (200µs/div)

(2V/div)

VOUT

(2V/div)

IIN

(200mA/div)

VSINK

(1V/div)

Turn-On to 1.5X Mode

(VIN = 3.2V; ILED = 150mA)

Time (200µs/div)

(2V/div)

VOUT

(2V/div)

IIN

(200mA/div)

VSINK

(1V/div)

Turn-On to 1X Mode

(VIN = 4.2V; ILED = 600mA)

Time (200µs/div)

(2V/div)

VOUT

(2V/div)

IIN

(500mA/div)

VSINK

(1V/div)

Turn-On to 2X Mode

(VIN = 3.2V; ILED = 600mA)

Time (200µs/div)

(2V/div)

VOUT

(2V/div)

IIN

(500mA/div)

VSINK

(1V/div)

Turn-Off from 1.5X Mode

(VIN = 3.2V; ILED = 150mA)

Time (200µs/div)

(2V/div)

IIN

(200mA/div)

(1V/div)

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

6Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Typical Characteristics

VIN = 3.6V, CIN = 4.7μF, C OUT = 2.2μF, C 1 = C2 = 1μF, TA = 25°C, unless otherwise noted.

Operating Characteristic

(VIN = 3.3V; 1.5X Mode; ILED = 300mA)

Time (2µs/div)

VIN

(100mV/div)

VSINK

(200mV/div)

VOUT

(200mV/div)

Operating Characteristic

(VIN = 2.9V; 2X Mode; ILED = 300mA)

Time (2µs/div)

VIN

(100mV/div)

VSINK

(200mV/div)

VOUT

(200mV/div)

LED Current vs. RSET

(Data = 1)

RSET (kΩ

)

ILED (mA)

100

200

300

400

500

600

700

800

900

1000

100 200 300 400 500 600 700 800 900 1000

TLAT vs. VIN

Input Voltage (V)

TLAT (µs)

100

120

140

160

2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 5.1 5.3 5.54.7 4.9

-40°C

25°C

85°C

TOFF vs. VIN

Input Voltage (V)

TOFF (µs)

100

120

140

160

180

3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 5.1 5.3 5.54.7 4.92.7 2.9

-40°C

25°C

85°C

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Typical Characteristics

VIN = 3.6V, CIN = 4.7μF, C OUT = 2.2μF, C 1 = C2 = 1μF, TA = 25°C, unless otherwise noted.

VIH vs. VIN Over Temperature

Input Voltage (V)

VIH (V)

0.4

0.5

0.6

0.7

0.8

0.9

1.0

3.1 3.3 3.5 3.7 3.92.7 2.9 4.1 4.3 4.5 5.1 5.3 5.54.7 4.9

-40°C

25°C

85°C

VIL vs. VIN Over Temperature

Input Voltage (V)

VIL (V)

0.4

0.5

0.6

0.7

0.8

0.9

1.0

3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 5.1 5.3 5.54.7 4.92.7 2.9

-40°C

25°C85°C

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

8Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Functional Description

The AAT3174 is a high efficiency, low noise, dual stage

tri-mode 1X/1.5X/2X charge pump device intended for

photo-flash LED applications. The device requires only

four external components: two ceramic capacitors for

the charge pump flying capacitors, one ceramic capacitor

for CIN, and one ceramic capacitor for COUT

The charge pump is designed to deliver regulated load

currents up to 800mA. The dual stage charge pump sec-

tion contains soft-start circuitry to prohibit excessive

inrush current during start-up. System efficiency is

maximized with a tri-mode, dual stage charge pump

topology. The internal clock oscillator at 1MHz allows the

use of small external components.

The tri-mode charge pump operation further optimizes

power conversion efficiency. Depending upon the vari-

ance of load current (at different modes), input voltage,

and nominal LED forward voltage, the charge pump will

operate in a 1X, 1.5X, or 2X mode to generate the output

voltage required to power the load for a given controlled

constant current. This results in significant power sav-

ings over voltage doubling architectures, especially when

the LEDs are also operated at lower current levels in

movie, viewing, or flashlight modes.

S2Cwire Serial Interface

The AAT3174 utilizes Skyworks single wire S2Cwire inter-

face to enable/disable the charge pump and adjust the

output current at 16 current levels. Each code defines the

output current to be a percentage of the maximum cur-

rent set by the resistor at the RSET pin (see Table 1).

Data Total Output (% of IMAX)

1 100.0

2 89.1

3 79.4

4 70.8

5 63.1

6 56.2

7 50.1

8 44.7

9 39.8

10 35.5

11 31.6

12 28.2

13 25.1

14 22.4

15 20.0

16 0.0

Table 1: Current Level Settings.

Functional Block Diagram

Charge Pump

Section 1

Charge Pump

Section 2

1MHz

Oscillator

Soft-Start

Control

C1+ C1- C2+ C2-

OUT

RSET

GND

EN/SET

VIN

System Control;

Cwire;

Timing

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

AAT3174

EN/SET

VIN

C1+C1-C2+C2-

VOUT

2.7V

to 5.5V

Flash

LED

GND

4.7μF

1μF

OUT

2.2μF

RSET ENFL

Figure 1: Flash/Torch Control Using the RSET Pin.

S2Cwire Serial Interface Timing

EN/SET

2n-1 n ≤ 16

Data Reg 0n

THI

TLO TLAT TOFF

The S2Cwire interface records rising edges of the EN/SET

pin and decodes them into 16 individual current level

settings with Code 1 reserved for maximum current.

Once EN/SET has been held in the logic high state for

time TLAT

, the programmed current is seen at the current

source outputs and the internal data register is reset to

0. For subsequent current level programming, the num-

ber of rising edges corresponding to the desired code

must be entered on the EN/SET pin.

When EN/SET is held low for an amount of time greater

than TOFF

, the AAT3174 enters into shutdown mode and

draws less than 1μA from VIN. Data and address regis-

ters are reset to 0 during shutdown.

Application Information

Flash/Torch Control Using the RSET Pin

An alternative method can be used for flash/torch con-

trol that eliminates the need to use the S2Cwire single-

wire interface. By using any typical digital I/O port, an

additional enable can be created (see Figure 1).

The I/O port output configuration can be any one of open-

drain NMOS, open-drain PMOS, or push-pull type. The

control will always act as an active-low flash enable or,

equivalently, an active-high torch enable (see Table 2).

EN ENFL Mode

0 0 Off

0 1 Off

1 0 Flash

1 1 Torch

Table 2: Flash/Torch Control Modes.

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

10 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

According to I/O port type, the following equations can

be used to calculate appropriate resistor values.

For an open-drain NMOS I/O port output configuration,

the line is pulled low to GND or left floating, according to

state. To calculate the appropriate R1 and R2 resistor

values, first calculate the R1 resistor value needed for the

desired torch level LED current:

600mA · 187kΩ

LED

(

torch

)

R1 =

Next, choose R2 based on the desired flash level LED cur-

rent:

R1 · 600mA · 187kΩ

R1 · ILED (flash) - 600mA · 187kΩ

R2 =

The current and resistance values used in the equations

come from the conditions placed on the IDX parameter of

the Electrical Characteristics table.

For examples of standard 1% values where the LED flash

current level is targeted for 700mA, see Table 3.

(kΩ)

ILED

Torch (mA)

ILED

Flash (mA)

920 193 122 703

732 205 153 701

649 210 173 707

562 223 200 703

Table 3: Open-Drain I/O Example Resistor Values.

If the I/O port must be configured as an open-drain PMOS

type output, the appropriate equations can be generated

from these same concepts. As done in the previous exam-

ple, the necessary values can then be calculated.

As a reference, the equations applicable to the PMOS

case are:

600mA · 187kΩ

ILED (flash)

R1 =

VIO

0.7

ILED (torch)

600mA · 187kΩ

R2 =

- 1

The value to use for VIO must come from the I/O supply

voltage used in the system. 0.7V is the typical value of

the VRSET parameter found in the Electrical Characteristics.

For a push-pull I/O port output configuration, first calcu-

late the overall RSET value needed for the desired flash

level LED current:

600mA · 187kΩ

ILED (flash)

RSET =

Next, choose a reasonable value for R1. A value that is

slightly larger than RSET

, calculated from above, is appro-

priate. Calculate R2 and then calculate the torch mode

current level that results:

RSET · R1

R1 - RSE

R2 =

ILED (torch) = 600mA · 187kΩ · -

R2 - R1

R1 · R2

VIO

0.7V · R2

⎛

⎝⎞

⎠

Once again, the current and resistance values used in

the equations come from the conditions placed on the IDX

parameter of the Electrical Characteristics table. 0.7V is

the typical value for the VRSET parameter. The value to

use for VIO must come from the I/O supply voltage used

in the system.

Example standard 1% values are provided in Table 4.

(kΩ)

ILED

Torch (mA)

ILED

Flash (mA)

169 1000 95 776

165 1000 111 792

162 1000 124 805

160 1000 132 813

Table 4: Push-Pull I/O Example Resistor Values.

In all of the approaches mentioned, the open-drain

NMOS or PMOS type configurations offer the most flexi-

bility for current level selection.

When configured as an output, if the I/O port is only

push-pull type, then the equivalent open-drain NMOS

can also be realized. To realize this, activate the port as

output only when driving the line low. Otherwise, to

release the line, set the port to be tri-stated.

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Device Power Efficiency

The AAT3174 power conversion efficiency depends on

the charge pump mode. By definition, device efficiency

is expressed as the output power delivered to the LED

divided by the total input power consumed.

η = POU

When the input voltage is sufficiently greater than the

LED forward voltage, the device optimizes efficiency by

operating in 1X mode. In 1X mode, the device is working

as a bypass switch and passing the input supply directly

to the output. The power conversion efficiency can be

approximated by,

= ≈

VF · ILED

VIN · IIN

VIN

Due to the very low 1X mode quiescent current, the

input current nearly equals the current delivered to the

LED. Further, the low-impedance bypass switch intro-

duces negligible voltage drop from input to output.

The AAT3174 further maintains optimized performance

and efficiency by detecting when the input voltage is not

sufficient to sustain LED current. The device automati-

cally switches to 1.5X mode when the input voltage

drops too low in relation to the LED forward voltage.

In 1.5X mode, the output voltage can be boosted to 3/2

the input voltage. The 3/2 conversion ratio introduces a

corresponding 1/2 increase in input current. For ideal

conversion, the 1.5X mode efficiency is given by:

= =

VF · ILED

VIN · 1.5IIN

1.5 · VIN

Similarly, when the input falls further, such that 1.5X

mode can no longer sustain LED current, the device will

automatically switch to 2X mode. In 2X mode, the out-

put voltage can be boosted to twice the input voltage.

The doubling conversion ratio introduces a correspond-

ing doubling of the input current. For ideal conversion,

the 2X mode efficiency is given by:

= =

VF · ILED

VIN · 2IIN

2 · VIN

LED Selection

The AAT3174 is designed to drive high-intensity white

LEDs. It is particularly suitable for LEDs with an operat-

ing forward voltage in the range of 4.2V to 1.5V.

The charge pump device can also drive other loads that

have similar characteristics to white LEDs. For various

load types, the AAT3174 provides a high-current, pro-

grammable ideal constant current source.

Capacitor Selection

Careful selection of the four external capacitors CIN, C1,

C2, and COUT is important because they will affect turn-on

time, output ripple, and transient performance. Optimum

performance will be obtained when low equivalent series

resistance (ESR) ceramic capacitors are used. In gen-

eral, low ESR may be defined as less than 100m. A

value of 1μF for the flying capacitors is a good starting

point when choosing capacitors. If the LED current sinks

are only programmed for light current levels, then the

capacitor size may be decreased.

Ceramic composition capacitors are highly recommended

over all other types of capacitors for use with the

AAT3174. Ceramic capacitors offer many advantages

over their tantalum and aluminum electrolytic counter-

parts. A ceramic capacitor typically has very low ESR, is

lowest cost, has a smaller PCB footprint, and is non-

polarized. Low ESR ceramic capacitors help maximize

charge pump transient response. Since ceramic capaci-

tors are non-polarized, they are not prone to incorrect

connection damage.

Equivalent Series Resistance

ESR is an important characteristic to consider when

selecting a capacitor. ESR is a resistance internal to a

capacitor that is caused by the leads, internal connec-

tions, size or area, material composition, and ambient

temperature. Capacitor ESR is typically measured in

milliohms for ceramic capacitors and can range to more

than several ohms for tantalum or aluminum electrolytic

capacitors.

Ceramic Capacitor Materials

Ceramic capacitors less than 0.1μF are typically made

from NPO or C0G materials. NPO and C0G materials

generally have tight tolerance and are very stable over

temperature. Larger capacitor values are usually com-

posed of X7R, X5R, Z5U, or Y5V dielectric materials.

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

12 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

Large ceramic capacitors are often available in lower-

cost dielectrics, but capacitors greater than 4.7μF are

not typically required for AAT3174 applications.

Capacitor area is another contributor to ESR. Capacitors

that are physically large will have a lower ESR when

compared to an equivalent material smaller capacitor.

These larger devices can improve circuit transient

response when compared to an equal value capacitor in

a smaller package size.

Thermal Protection

The AAT3174 has a thermal protection circuit that will

shut down the charge pump if the die temperature rises

above the thermal limit, as is the case during a short-

circuit of the OUT pin.

PCB Layout

To achieve adequate electrical and thermal performance,

careful attention must be given to the PCB layout. In the

worst-case operating condition, the chip must dissipate

considerable power at full load. Adequate heat-sinking

must be achieved to ensure intended operation.

Figure 2 illustrates an example of an adequate PCB lay-

out. The bottom of the package features an exposed

metal paddle. The exposed paddle acts, thermally, to

transfer heat from the chip and, electrically, as a ground

connection.

The junction-to-ambient thermal resistance (JA) for the

package can be significantly reduced by following a

couple of important PCB design guidelines.

The PCB area directly underneath the package should be

plated so that the exposed paddle can be mated to the

top layer PCB copper during the re-flow process. This

area should also be connected to the top layer ground

pour when available. Further, multiple copper plated

thru-holes should be used to electrically and thermally

connect the top surface paddle area to additional ground

plane(s) and/or the bottom layer ground pour.

The chip ground is internally connected to both the paddle

and the GND pin. The GND pin conducts large currents

and it is important to minimize any differences in potential

that can result between the GND pin and exposed paddle.

It is good practice to connect the GND pin to the exposed

paddle area using a trace as shown in Figure 2.

Figure 2: Example PCB Layout.

The flying capacitors C1 and C2 should be connected

close to the chip. Trace length should be kept short to

minimize path resistance and potential coupling. The

input and output capacitors should also be placed as

close to the chip as possible.

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

202100A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 25, 2012

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

TDFN33-12 RSXYY AAT3174IWP-T1

Skyworks Green™ products are compliant with

all applicable legislation and are halogen-free.

For additional information, refer to Skyworks

Deﬁnition of Green™, document number

SQ04-0074.

Package Information

TDFN33-123

Top View Bottom View

Detail "A"

Side View

3.00

0.05

Index Area Detail "A"

1.70

0.05

3.00

0.05

0.23

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.

AAT3174

DATA SHEET

High Current, High Efficiency Charge Pump

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