DATA SHEET

AAT1171

600mA Voltage-Scaling Step-Down Converter

for RF Power Amplifiers with Bypass Switch

General Description

The AAT1171 SwitchReg™ dynamically controls the oper-

ating voltage of a WCDMA or CDMA power amplifier

inside single-cell, lithium-ion battery-powered systems.

The AAT1171 outputs a voltage between 0.6V and 3.6V,

thereby optimizing the amplifier efficiency at both low

and high transmit levels.

The AAT1171 output voltage is controlled via an analog

signal from the baseband processor. It can deliver

600mA of continuous load current while maintaining a

low 45μA of no load quiescent current. The 2MHz switch-

ing frequency minimizes the size of external components

while keeping switching losses low. To further improve

system efficiency, an 85mΩ bypass MOSFET transistor is

also included to allow the PA to be powered directly from

the battery.

The AAT1171 maintains high efficiency thoughout the

entire load range in Light Load (LL) mode, and can be

forced into Pulse Wide Modulation (PWM) mode for low

noise operation or can be synchronized to an external

clock.

The AAT1171 is available in a Pb-free, space-saving

TDFN33-12 or 12-pin wafer-level chip scale package

(WLCSP) and is rated over the -40°C to +85°C tempera-

ture range.

Features

•

V

IN

Range: 2.7V to 5.5V

Variable Output Voltage: 0.6V to 3.6V

600mA Output Current

DAC Input: 0.2V to 1.2V

High Output Accuracy: ±3%

45μA No Load Quiescent Current

Internal Soft Start Limits Startup Current and Output

Voltage Overshoot

Synchronizable to External 19.8MHz System Clock

Over-Temperature and Current Limit Protection

Integrated 85mΩ Bypass MOSFET

2MHz Operation

PWM/LL Control with Override

Fast Start-Up:

▪

50μs (AAT1171-4, AAT1171-5)

▪

150μs (AAT1171-1)

100% Duty Cycle Operation

<30μs Output Voltage Response Time

3x3mm 12-Pin TDFN or 1.535x2.235mm 12-Pin

WLCSP Package

Temperature Range: -40°C to +85°C

•

Applications

• WCDMA or CDMA PA in Cellular Phones, Smartphones,

Feature Phones, etc.

• Express Card

• PCMCIA Data Cards

Typical Application

VIN

VCC

C

IN

4.7μF

LX

C

OUT

4.7μF

L1

2.2μH

0.6V - 3.6V

VIN

VCC

C

IN

4.7μF

LX

L1

4.7μH

0.6V - 3.6V

–

AAT1171-1/

AAT1171-4

BYPASS

MODE/SYNC

EN

DAC

GNDx2

VOUT

AAT1171-5

BYPASS

MODE/SYNC

EN

DAC

VOUT

–

C

OUT

10μF

V

CC2

V

CONT

V

REF

V

CC2

PA

GNDx2

V

REF

V

CC2

V

CONT

V

CC2

PA

DAC

Baseband

Processor

TX

RX

DAC

Baseband

Processor

TX

RX

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

201999B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2013

1

DATA SHEET

AAT1171

600mA Voltage-Scaling Step-Down Converter

for RF Power Amplifiers with Bypass Switch

Pin Descriptions

Pin #

TDFN33-12

1

2, 3

WLCSP-12

N/A

5, 9

Symbol

N/C

VOUT

Function

Not connected.

Feedback input pin. This pin is connected to the converter output. It is used to

complete the control loop, regulating the output voltage to the desired value.

When in bypass mode, a low resistance MOSFET is connected between this pin

and VIN.

Bias supply. Supply power for the internal circuitry. Connect to input power via

low pass

ﬁ

lter with decoupling to AGND.

Analog ground. Connect the return of all small signal components to this pin.

Control voltage input from a DAC. Input voltage between 0.2V and 1.2V to con-

trol output voltage of the converter. Force pin to 1.3V for bypass switch enable.

Enable DC/DC converter, active high.

Enable control to bypass the DC/DC converter when PA transmitting at full

power from low battery voltage. Active high.

This pin is used to program the device between PWM and LL mode:

HIGH - PWM Mode Only

LOW - LL Mode: PWM operation for loads above 100mA and variable switching

frequency for loads below 100mA. Connecting the SYNC pin to the system clock

(19.8MHz) will override the internal clock and force the switching frequency to

the external clock frequency divided by 10.

Input supply voltage for the converter. Must be closely decoupled.

Main power ground. Connect to the output and input capacitor return.

Switching node. Connect the inductor to this pin. It is connected internally to

the drain of both low- and high-side MOSFETs.

Exposed paddle (bottom). Connect to ground directly beneath the package.

4

5

6

7

8

7

6

1

2

3

VCC

AGND

DAC

EN

BYPASS

9

4

MODE/SYNC

10

11

12

EP

12

8, 11

10

N/A

VIN

PGND

LX

Pin Configuration

TDFN33-12

(Top View)

WLCSP-5

(Top View)

11: PGND

8: PGND

N/C

VOUT

VCC

AGND

DAC

1

2

3

4

5

6

12

11

10

9

8

7

LX

PGND

VIN

MODE/SYNC

BYPASS

EN

LX

VOUT

MODE/SYNC

BYPASS

10

9

4

3

11

8

5

2

12

7

6

1

VIN

VCC

AGND

DAC

5: VOUT

2: EN

2

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

201999B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2013

DATA SHEET

AAT1171

600mA Voltage-Scaling Step-Down Converter

for RF Power Amplifiers with Bypass Switch

Absolute Maximum Ratings

1

Symbol

V

CC

, V

IN

V

LX

V

OUT

V

N

T

J

T

LEAD

Description

Input Voltage and Bias Power to GND

LX to GND

VOUT to GND

EN, DAC, BYPASS, MODE/SYNC to GND

Operating Junction Temperature Range

Maximum Soldering Temperature (at leads, 10 sec)

Value

6.0

-0.3 to V

IN

+ 0.3

-0.3 to V

IN

+ 0.3

-0.3 to 6.0

-40 to 150

300

Units

V

°C

Thermal Information

2

Symbol

P

D

θ

JA

Description

Maximum Power Dissipation, T

A

= 25°C

Thermal Resistance, T

A

= 25°C

TDFN33-12

2, 3

WLCSP-12

2, 4

TDFN33-12

WLCSP-12

Value

2.0

0.88

50

114

Units

W

°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 FR4 board; for the WLCSP package, use the NSMD (none-solder mask defined) pad style for tighter control on the copper etch process.

3. Derate 20mW/°C above 25°C ambient.

4. Derate 8.8mW/°C above 25°C ambient.

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

201999B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2013

3

DATA SHEET

AAT1171

600mA Voltage-Scaling Step-Down Converter

for RF Power Amplifiers with Bypass Switch

Electrical Characteristics

1

T

A

= -40°C to +85°C, unless otherwise noted. V

IN

= V

CC

= 3.6V; typical values are T

A

= 25°C.

Symbol

V

IN

V

UVLO

V

OUT

V

DACIN

I

Q

I

SHDN

I

LIM

Description

Input Voltage

UVLO Threshold

UVLO Hysteresis

V

OUT

Programmable Range

Input Voltage Range from DAC

Quiescent Current

Shutdown Current

P-Channel Current Limit

High Side Switch On Resistance

Low Side Switch On Resistance

Bypass Switch Resistance

LX Leakage Current

Conditions

V

IN

Rising

Min

2.7

Typ

2.6

200

Max

5.5

Units

V

mV

V

μA

A

mΩ

μA

%

%/V

kΩ

V

MHz

°C

mA

μs

V

μA

μs

0.6

0.2

No Load, Light Load

No Load, PWM, V

CC

Bias Current

EN = AGND = PGND, MODE/SYNC = V

IN

or

GND

T

A

= 25°C

45

420

3.6

1.2

70

1.0

1.2

R

DS(ON)H

R

DS(ON)L

R

DS(ON)BP

I

LXLEAK

∆V

OUT

/

Load Regulation

V

OUT

∆V

OUT

/

Line Regulation

V

OUT

/∆V

IN

R

OUT

Feedback Impedance

V

OUT

Output Voltage Accuracy

F

OSC

Oscillator Frequency

T

SD

Over-Temperature Shutdown Threshold

T

HYS

Over-Temperature Shutdown Hysteresis

I

LL

Light Load Load Current Threshold

t

VOUTS

Output Voltage Settling Time

PWM/Light Load/EN

Enable Threshold Low

V

EN(L)

V

EN(H)

Enable Threshold High

I

EN

Input Low Current

t

EN

Turn-On Enable Response Time

V

DAC

= 1.3V or BYPASS = VIN

V

CC

= 5.5V, V

LX

= 0 to V

CC

, EN = 0V

I

LOAD

= 0 to 500mA

1.6

230

85

1

0.5

0.2

V

DAC

= 0.6V, I

LOAD

= 0

1.746

170

1.8

2.0

140

15

100

1.854

V

OUT

= 0.6V to V

OUT(MAX)

, MODE/SYNC = V

IN

30

0.6

V

CC

= 5.5V

AAT1171-1: EN = Low to High, MODE/SYNC

= High, V

DAC

= 1.2V

AAT1171-4/AAT1171-5: EN = Low to High,

MODE/SYNC = High, V

DAC

= 1.2V

Sync to 19.8MHz

2

1.4

-1.0

150

50

19.8

V

IN

-

0.4

1.0

MODE/SYNC

F

MODE/SYNC

Synchronization Frequency

V

MODE/

MODE/SYNC High Level Threshold

SYNC(H)

MHz

V

0.4

V

μA

V/V

V

MODE/

SYNC(L)

MODE/SYNC Low Level Threshold

V

SYNC

= GND or V

CC

-1.0

3

I

MODE/SYNC

MODE/SYNC Low Current

DAC Input

Gain

Output Voltage/DAC Voltage

3

1.0

1. The AAT1171 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. Please contact Sales for other synchronization frequencies.

3. Please contact Sales for other output voltage/DAC voltage gains.

4

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

201999B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2013

DATA SHEET

AAT1171

600mA Voltage-Scaling Step-Down Converter

for RF Power Amplifiers with Bypass Switch

Typical Characteristics

Efficiency vs. Output Current

(LL Mode; V

OUT

= 3.3V)

100

90

1.0

Load Regulation

(LL Mode; V

OUT

= 3.3V)

Output Voltage Error (%)

V

IN

= 3.9V

Efficiency (%)

0.5

80

70

60

50

40

0.1

V

IN

= 5.0V

V

IN

= 3.6V

V

IN

= 4.2V

V

IN

= 5.0V

0.0

-0.5

V

IN

= 4.2V

1

10

100

1000

-1.0

0.1

1

10

100

1000

Output Current (mA)

Efficiency vs. Output Current

(PWM Mode; V

OUT

= 3.3V)

90

80

Load Regulation

(PWM Mode; V

OUT

= 3.3V)

1.0

Output Voltage Error (%)

100

Efficiency (%)

70

60

50

40

30

20

10

0

0.1

1

10

0.5

V

IN

= 5.0V

V

IN

= 3.6V

V

IN

= 4.2V

V

IN

= 5.0V

0.0

V

IN

= 3.6V

-0.5

V

IN

= 4.2V

1

10

100

1000

100

1000

-1.0

0.1

Output Current (mA)

Efficiency vs. Output Current

(LL Mode; V

OUT

= 2.5V)

V

IN

= 3.0V

Output Voltage Error (%)

100

90

1.0

Load Regulation

(LL Mode; V

OUT

= 2.5V)

Efficiency (%)

0.5

80

70

60

50

40

0.1

1

10

V

IN

= 5.0V

V

IN

= 4.2V

V

IN

= 4.2V

V

IN

= 5.0V

0.0

-0.5

V

IN

= 3.0V

100

1000

-1.0

0.1

1

10

100

1000

Output Current (mA)

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

201999B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2013

5

参数名称	属性值
最大工作温度	85 Cel
最小工作温度	-55 Cel
负偏差	10 %
正偏差	10 %
额定直流电压urdc	10 V
加工封装描述	芯片, ROHS COMPLIANT
无铅	Yes
欧盟RoHS规范	Yes
状态	ACTIVE
端子涂层	锡
安装特点	表面贴装
制造商系列	GRM21
尺寸编码	0805
电容	4.7 uF
包装形状	矩形的 PACKAGE
电容类型	陶瓷
端子形状	WRAPAROUND
温度系数	15%
温度特性代码	×5R
多层	Yes

C1608X5ROJ475K

C1608X5ROJ475K概述

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