AAT3670ISK-4.2-T1 - Skyworks Solutions, Inc.

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

General Description

The AAT3670 BatteryManager is a highly integrated sin-

gle-cell lithium-ion/polymer (Li-ion) battery charger and

system power management IC that enables simultane-

ous battery charging and full system usage without com-

promising the battery’s charge cycle life. It operates with

low-voltage AC adapter (ADP) and USB inputs and

requires a minimum number of external components.

The AAT3670 selects ADP or USB to power the system

load and charge the battery when ADP/USB power is

available. The AAT3670 precisely regulates battery

charge voltage and current for 4.2V Li-ion cells. Charge

current can be programmed up to 1.6A for ADP charging

and 0.9A or 0.1A for USB charging by resistors on the

ADPSET / USBSET pins. The charge termination current

threshold is set by an external resistor on the TERM pin.

The AAT3670 has a voltage-sensed charge current

reduction loop that enables system operation without a

power shortage. When the input voltage falls below the

programmable charge reduction threshold, the device

automatically reduces the charge current until the input

voltage returns to the threshold voltage.

Battery temperature and charge state are fully monitored

for fault conditions. In the event of a battery over-volt-

age/short-circuit/over-temperature condition, the char-

ger will automatically shut down, protecting the charging

device, control system, and battery. Two status monitor

output pins (STAT1 and STAT2) are provided to indicate

battery charge status by directly driving external LEDs.

The AAT3670 is available in a Pb-free, thermally-

enhanced, space-saving 24-pin 4 × 4mm QFN package.

Features

• ADP, USB, or Battery Powers System Load Through

Internal Current-Limited Switches

• Simultaneous Battery Charging and System Usage

• Voltage Sensed Charge Reduction Loop to Minimize

Charge Time, Even While the System Operates

• Digitized Thermal Loop

• Battery Power Enable (ENBAT)

• Battery Charge Timer (CT)

• Battery Temperature Monitoring (TS)

• Battery Charge Status Report (STATx)

• Automatic Recharge Sequencing

• Battery Under-Voltage, Over-Voltage, and Over-

Current Protection

• System Load Current Limiting

• Thermal Protection

• 24-pin 4 × 4mm QFN Package

Applications

• Cellular Telephones

• Digital Still Cameras

• Personal Data Assistants (PDAs)

• Hand Held PCs

• MP3 Players and PMP

• Other Li-ion Battery Powered Devices

Typical Application

System Load

OUT

BATS

BAT

VTS

CHRADP

CHRUSB

TERM

GND

STAT1

STAT2

ADP

USB

USBSEL

USBSET

ADPSET

USBLIM

ADPLIM

AAT3670

Adapter Input

USB Input

Enable

USB Hi/Lo Select

Enable Battery to OUT ENBAT

Single Cell

Li-Ion/Poly

Battery

CADP

10μF

CBAT

10μF

RTERM

CUSB

10μF

RADPSET RADPLIM

RUSBSET RUSBLIM

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Pin Descriptions

Pin # Name Type Function

1 USBSEL I Logic input. High for 100% USB charge current set by USBSET; low for 20% (constant cur-

rent charge mode) or 50% (trickle charge mode) charge current set by the USBSET resistor.

2, 3 OUT O System load output; a capacitor with a minimum value of 10μF (including all capacitance on

the load of OUT) is required.

4, 5 BAT I/O Battery pack input/output. For best operation, a 1μF ceramic capacitor should be placed

between BAT and GND.

6 ADP I AC adapter input, source of system load and battery charging. Minimum 1μF input capacitor.

7 VTS O Voltage reference for battery temperature sensing.

8TSI

Battery temperature sensing input. Use an NTC resistor from TS pin to ground and a 1%

standard resistor that has equal resistance of the NTC at 25°C from VTS to TS for battery

temperature sensing. Tie TS pin to ground to disable the temperature sensing function.

9 BATS I Battery sense pin.

10 CHRADP I/O

ADP voltage sensed charge reduction programmable pin. A resistor divider from ADP to this

pin and GND sets the charge reduction threshold. When this pin is open, the charge reduc-

tion threshold is 4.6V. If this pin is tied to the ADP pin, the charge reduction is disabled.

11 ADPLIM I Connect a resistor to this pin to set the ADP input current limit (including load switch and

charger currents).

12 USBLIM I Connect a resistor to this pin to set the USB input current limit (including load switch and

charger currents).

13 ADPSET I

Connect a resistor to this pin to set the ADP charge current (for trickle charge and constant

current charge). The CC current set by this pin should be less than the current limit set by

ADPLIM, otherwise the CC current will be limited by ADPLIM.

14 USBSET I

Connect a resistor to this pin to set the USB charge current (for trickle charge and constant

current charge). The CC current set by this pin should be less than the current limit set by

USBLIM, otherwise the CC current will be limited by USBLIM.

15 GND I/O Common ground.

16 TERM I Connect a resistor to this pin to program the charge termination current threshold. No termi-

nation current setting when this pin is pulled up to a logic high level.

17 EN I ADP/USB enable input. High or ﬂ oating (internal pull-up) to enable ADP/USB switch and ADP/

USB battery charging; low to disable ADP/USB switch and ADP/USB battery charging.

18 CT I

Battery charge timer input pin. Connect a capacitor to this pin to set the ADP charge timers.

No time-out for USB charging. Timers are disabled when this pin is grounded. The timer is

suspended if the battery temperature is not within 0 to 50ºC or is in charge reduction (either

due to the supply voltage dropping or the device temperature rising) is activated. The timer

continues where it left off after the battery temperature returns to normal and the device is

out of the charge reduction loops.

19 STAT2 O Open drain charger status reporting.

20 STAT1 O Open drain charger status reporting.

21 N/C No connection.

22 USB I USB input, source of system load and battery charging when ADP is not available. Minimum

1μF input capacitor.

23 CHRUSB I/O

USB voltage sensed charge reduction programmable pin. A resistor divider from USB to this

pin and GND sets the charge reduction threshold. When this pin is open, the charge reduc-

tion threshold is 4.5V. If this pin is tied to the USB pin, charge reduction is disabled.

24 ENBAT I Battery load switch enable, active high.

EP Exposed paddle (bottom). Connect to ground as closely as possible to the device.

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Pin Configuration

QFN44-24

(Top View)

USBSEL

OUT

BAT

ADP

VTS

BATS

CHRADP

ADPLIM

USBLIM

GND

TERM

USBSET

ADPSET

STAT2

STAT1

N/C

USB

CHRUSB

ENBAT

Absolute Maximum Ratings1

Symbol Description Value Units

VPADP, USB, BAT, OUT, BATS <30ms, Duty Cycle < 10% -0.3 to 7.0 V

VPADP, USB BAT, OUT, BATS Continuous -0.3 to 6 V

USBSEL, EN, ENBAT, STAT1, STAT2 -0.3 to 6 V

VNVTS, TS, CT, ADPLIM, USBLIM, ADPSET, USBSET, TERM, CHRADP, CHRUSB -0.3 to VP + 0.3 V

TJOperating Junction Temperature Range -40 to 150 °C

TLEAD Maximum Soldering Temperature (at Leads) 300 °C

Thermal Information2

Symbol Description Value Units

JA Maximum Thermal Resistance 50 °C/W

PDMaximum Power Dissipation 2.0 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 a FR4 board.

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Electrical Characteristics

VADP = 5V, TA = -40°C to +85°C; unless otherwise noted, typical values are TA = 25°C.

Symbol Description Conditions Min Typ Max Units

Operation

VADP

AC Adapter Operating Voltage

Range 4.35 5.5 V

VUSB USB Operating Voltage Range 4.35 5.5 V

VBAT Battery Operating Voltage Range 3.0 VBAT_EOC V

VUVLO_ADP ADP Under-Voltage Lockout Rising Edge 3.6 V

Hysteresis 0.3

VUVLO_USB USB Under-Voltage Lockout Rising Edge 3.6 V

Hysteresis 0.3

VUVLO_BAT BAT Under-Voltage Lockout Rising Edge 2.8 2.9 3.0 V

Hysteresis 0.1

IADP_OP ADP Normal Operating Current VADP = VEN = 5V, ICC = 1A 0.5 1 mA

IADP_SHDN ADP Shutdown Mode Current VADP = 5V, VEN = 0V, VENBAT = 0V, No Load 1 μA

IUSB_OP USB Normal Operating Current VUSB = VEN = 5V, ICC = 0.5A 0.5 1 mA

IUSB_SHDN USB Shutdown Mode Current VUSB = 5V, VEN = 0V, VENBAT = 0V, No Load 1 μA

IBAT_OP Battery Operating Current VBAT = VBAT_EOC, VADP = GND, VUSB = GND,

VENBAT = 5V, No Load 45 80 μA

IBAT_SLP Battery Sleep Current VBAT = VBAT_EOC, VADP = 5V or VUSB = 5V,

VEN = VENBAT = 5V 25μA

IBAT_SHDN Leakage Current from BAT Pin VBAT = VBAT_EOC, VENBAT = 0V 1 μA

Power Switches

RDS(ON)_SWA ADP-to-OUT FET On Resistance VADP = 5.0V 0.4 

RDS(ON)_SWU USB-to-OUT FET On Resistance VUSB = 5.0V 0.7 

RDS(ON)_SWB BAT-to-OUT FET On Resistance VBAT = 4.2V 0.1 0.2 

VBAT = 4.2V, TA = 25°C 165 m

RDS(ON)_CHA

ADP Battery Charging FET

On Resistance VADP = 5.0V 0.4 

RDS(ON)_CHU

USB Battery Charging FET

On Resistance VUSB = 5.0V 0.7 

Battery Charge Voltage Regulation

VBAT_EOC Output Charge Voltage Regulation1For 4.2V Cells 4.158 4.20 4.242 V

VMIN Preconditioning Voltage Threshold 2.8 2.9 3.0 V

VRCH Battery Recharge Voltage Threshold VBAT_EOC

-0.17

VBAT_EOC

-0.1

VBAT_EOC

-0.05 V

VCHR_TH

Default ADP Charge Reduction

Threshold

CHRADP Open; Reduce Charge Current

When ADP is Below VCHR_TH

4.6

Default USB Charge Reduction

Threshold

CHRUSB Open; Reduce Charge Current

When USB is Below VCHR_TH

4.5

VCHR_REG

CHRADP and CHRUSB Pin Voltage

Accuracy 1.9 2.0 2.1 V

1. The output charge voltage accuracy is specified over the 0° to 70°C ambient temperature range; operation over the -40°C to +85°C temperature range is guaranteed by

design.

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Electrical Characteristics (continued)

VADP = 5V, TA = -40°C to +85°C; unless otherwise noted, typical values are TA = 25°C.

Symbol Description Conditions Min Typ Max Units

Current Regulation

ILIM_ADP Maximum ADP Current Limit 1.6 A

ILIM_USB Maximum USB Current Limit 0.9 A

ILIM_BAT BAT_OUT Current Limit (Fixed) 2.3 A

ICH_CC_ADP ADP Charge Constant Current Charge Range 100 1600 mA

ICH_CC_USB_H

USB High-Power Charge Constant Current

Charge Range USBSEL = 5V 50 900 mA

ICH_CC_USB_L

USB Low-Power Charge Constant Current

Charge Range USBSEL = 0V 10 180 mA

ICH_CC/

ICH_CC

Current Regulation Tolerance ICH_CC_ADP = 1A; ICH_CC_USB_H

= 0.5A; ICH_CC_USB_L = 0.1A -12 12 %

ICH_TKL_ADP ADP Charge Trickle Charge 10 % ICH_CC_ADP

ICH_TKL_USB_H USB High-Power Charge Trickle Charge USBSEL = 5V 10 % ICH_CC_USBH

ICH_TKL_USB_L USB Low-Power Charge Trickle Charge USBSEL = 0V 50 % ICH_CC_USBL

VADPLIM ADPLIM Pin Voltage Regulation 2 V

VUSBLIM USBLIM Pin Voltage Regulation 2 V

VADPSET ADPSET Pin Voltage Regulation 2 V

VUSBSET USBSET Pin Voltage Regulation 2 V

VTERM TERM Pin Voltage Regulation 2 V

KI_CC_ADP

Constant Current Charge Current Set Factor:

ICH_ADP/IADPSET

29300

KI_CC_USBH

Constant Current Charge Current Set Factor:

ICH_USB/IUSBSET

USBSEL = 5V 17900

KI_CC_USBL

Constant Current Charge Current Set Factor:

ICH_USB/IUSBSET

USBSEL = 0V 3600

KI_LIM_ADP Current Limit Set Factor: ILIM_ADP/IADPLIM 27800

KI_LIM_USBH Current Limit Set Factor: ILIM_USB/IUSBLIM USBSEL = 5V 17600

KI_LIM_USBL Current Limit Set Factor: ILIM_USB/IUSBLIM USBSEL = 0V 3500

KI_TERM Termination Current Set Factor: ICH_TERM/ITERM 2000

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Electrical Characteristics (continued)

VADP = 5V, TA = -40°C to +85°C; unless otherwise noted, typical values are TA = 25°C.

Symbol Description Conditions Min Typ Max Units

Logic Control/Protection

VEN Input High Threshold 1.6 V

VEN Input Low Threshold 0.4 V

VSTATx Output Low Voltage STATx Pin Sinks 8mA 0.4 V

Fast Charge (Constant Current and Constant

Voltage Charges Together) Timeout CCT = 100nF ADP 6 hour

USB inﬁ nite

TTKL Trickle Charge Timeout ADP Tc/8

USB inﬁ nite

VOVP Battery Over-Voltage Protection Threshold VBAT_EOC +

0.1

VBAT_EOC

+ 0.15

VBAT_EOC

+ 0.2 V

IOCP Battery Charge Over-Current Protection Threshold In All Modes 100 %ICH_CC

IVTS VTS Sourcing Capability VVTS = 2.5V 1mA

TS1 TS Hot Temperature Fault Threshold 28 30 32 %VTS

Hysteresis 2

TS2 TS Cold Temperature Fault Threshold 70 72 74 %VTS

Hysteresis 2

TLOOP_IN Digital Thermal Loop Entry Threshold For ADP Charging 115 ºC

TLOOP_OUT Digital Thermal Loop Exit Threshold For ADP Charging 95 ºC

TLOOP_REG Digital Thermal Loop Regulated Temperature For ADP Charging 100 ºC

TSHDN Chip Thermal Shutdown Temperature Threshold 140 ºC

Hysteresis 15

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

Constant Current vs. Set Resistor

(VIN = 5V; VBAT = 3.5V)

Constant Current (A)

Set Resistor (kΩ

)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

10 100 1000

ADP

USBL

USBH

Adapter Mode Supply Current vs. ADPSET Resisto

(VIN = 5V; VBAT = 3.5V)

Supply Current (mA)

ADPSET Resistor (kΩ

)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

10 100 1000

ICCM

ITRICKLE

USB Mode Supply Current vs. USBSET Resistor

(USBL; VIN = 5V; VBAT = 3.5V)

Supply Current (mA)

USBSET Resistor (kΩ

)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

10 100 1000

ICCM

ITRICKLE

USB Mode Supply Current vs. USBSET Resisto

(USBH; VIN = 5V; VBAT = 3.5V)

Supply Current (mA)

USBSET Resistor (kΩ

)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

10 100 1000

ICCM

ITRICKLE

End of Charge Voltage vs. Supply Voltage

End of Charge Voltage (V)

Supply Voltage (V)

4.16

4.18

4.20

4.22

4.24

4.5 4.75 5.0 5.25 5.5

ADP

USBH

USBL

End of Charge Voltage vs. Temperature

End of Charge Voltage (V)

Temperature (°

4.16

4.18

4.20

4.22

4.24

-40 -15 10 35 60 8

USBH

USBL

ADP

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

Recharge Threshold Voltage vs. Temperature

(VIN = 5.0V)

Recharge Threshold Voltage (V)

Temperature (°

3.96

4.00

4.04

4.08

4.12

4.16

4.20

-40 -15 10 35 60 85

USBH

USBL

ADP

Preconditioning Threshold Voltage vs. Temperatur

(VIN = 5.0V)

Preconditioning Threshold

Voltage (V)

Temperature (°

2.75

2.80

2.85

2.90

2.95

3.00

3.05

-40 -15 10 35 60 85

USBH

USBL

ADP

BAT to OUT Switch Voltage vs. Load Current

(VBAT = 3.95V)

BAT to OUT Switch Voltage (V)

Load Current (mA)

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0.2

0.4

0.6

0.8

1.2

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200

25°C

+85°C

-40°C

Preconditioning Charging Current vs. Temperatur

(VIN = 5.0V)

Preconditioning Charging

Current (mA)

Temperature (°

100

120

-40 -15 10 35 60 85

ADP

USBH, USBL

Charging Current vs. Battery Voltage

(ADP; ADPSET = 57.6kΩ

)

Charging Current (mA)

Battery Voltage (V)

200

400

600

800

1000

1200

2.5 2.9 3.3 3.7 4.1 4.5

Charging Current vs. Battery Voltage

(USBH; USBSET = 71.5kΩ

)

Charging Current (mA)

Battery Voltage (V)

100

200

300

400

500

600

2.5 2.9 3.3 3.7 4.1 4.5

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

Charging Current vs. Battery Voltage

(USBL; USBSET = 71.5kΩ

)

Charging Current (mA)

Battery Voltage (V)

100

120

2.5 2.9 3.3 3.7 4.1 4.5

Constant Charge Current vs. Temperatur

(VIN = 5.0V)

Constant Charge Current (mA)

Temperature (°

100

200

300

400

500

600

700

800

900

1000

1100

-40 -15 10 35 60 85

ADP

USBL

USBH

Constant Charging Current vs. Supply Voltage

(ADP; CHRADP = Open; ADPSET = 57.6kΩ

)

Constant Charging Current (mA)

Supply Voltage (V)

200

400

600

800

1000

1200

4.0 4.5 5.0 5.5 6.0

VBAT = 3.3V, 3.6V, 3.9V

Constant Charging Current vs. Supply Voltage

(ADP; CHRADP = USB; ADPSET = 57.6kΩ

)

Constant Charging Current (mA)

Supply Voltage (V)

200

400

600

800

1000

1200

4.0 4.5 5.0 5.5 6.

VBAT = 3.9V

VBAT = 3.6V

VBAT = 3.3V

Constant Charging Current vs. Supply Voltage

(USBL; CHRUSB = Open; USBSET = 71.5kΩ

)

Constant Charging Current (mA)

Supply Voltage (V)

100

120

4.0 4.5 5.0 5.5 6.0

VBAT = 3.3V, 3.6V

VBAT = 3.9V

Constant Charging Current vs. Supply Voltage

(USBL; CHRUSB = USB; USBSET = 71.5kΩ

)

Constant Charging Current (mA)

Supply Voltage (V)

100

120

4.0 4.5 5.0 5.5 6.0

VBAT = 3.3V

VBAT = 3.6V

VBAT = 3.9V

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

Constant Charging Current vs. Supply Voltage

(USBH; CHRUSB = Open; USBSET = 71.5kΩ

)

Constant Charging Current (mA)

Supply Voltage (V)

100

200

300

400

500

600

4.0 4.5 5.0 5.5 6.

VBAT = 3.3V

VBAT = 3.6V

VBAT = 3.9V

Constant Charging Current vs. Supply Voltage

(USBH; CHRUSB = USB; USBSET = 71.5kΩ

)

Constant Charging Current (mA)

Supply Voltage (V)

100

200

300

400

500

600

4.0 4.5 5.0 5.5 6.0

VBAT = 3.3V

VBAT = 3.6V

VBAT = 3.9V

Constant Charging Current vs.

Supply Voltage

(ADP; CHRADP = Open; VBAT = 3.6V; ADPSET = 57.6kΩ

)

Constant Charging Current (mA)

Supply Voltage (V)

200

400

600

800

1000

1200

4.3 4.4 4.5 4.6 4.7 4.8 4.9

25°C

-40°C

+85°C

Constant Charging Current vs.

Supply Voltage

(USBL; CHRUSB = Open;

VBAT = 3.6V; USBSET = 71.5k

)

Constant Charging Current (mA)

Supply Voltage (V)

100

120

4.3 4.4 4.5 4.6 4.7 4.8 4.9

+85°C+25°C

-40°C

Constant Charging Current vs.

Supply Voltage

(USBH; CHRUSB = Open; VBAT = 3.6V; USBSET = 71.5k

)

Constant Charging Current (mA)

Supply Voltage (V)

100

200

300

400

500

600

4.3 4.4 4.5 4.6 4.7 4.8 4.9

25°C

-40°C

+85°C

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

201879B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

VIH vs. Supply Voltage

(ADP or USBL or USBH; EN = Rising)

VIH (V)

Supply Voltage (V)

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

-40°C 25°C

85°C

VIL vs. Supply Voltage

(ADP or USBL or USBH; EN = Falling)

VIL (V)

Supply Voltage (V)

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

-40°C25°C

+85°C

VIH vs. Supply Voltage

(ENBAT = Rising)

VIH (V)

Battery Voltage (V)

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

-40°C25°C

85°C

VIL vs. Supply Voltage

(ENBAT = Falling)

VIL (V)

Battery Voltage (V)

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

-40°C25°C

85°C

Adapter and Charging Current vs. Output Current

(VBAT = 3.6V)

Current (mA)

Output Current (mA)

200

400

600

800

1000

1200

1400

1600

1800

0 200 400 600 800 1000

IADP

ICH

USB and Charging Current vs. Output Current

(USBL; VBAT = 3.6V)

Current (mA)

Output Current (mA)

-1000

-800

-600

-400

-200

200

400

0 200 400 600 800 1000

ICH

IUSBL

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

USB and Charging Current vs. Output Current

(USBH; VBAT = 3.6V)

Current (mA)

Output Current (mA)

-200

200

400

600

800

1000

1200

0 200 400 600 800 1000

IUSBH

ICH

ADP Charge Current vs. Time

ADP Voltage (top) (V)

ADP Peripheral Current

Consumption (middle) (A)

ADP Charge Current (A)

Time

4.0

4.5

5.0

012345

0.0

0.5

1.0

0.0

0.5

Charge Reduction

Mode Activated

USB Charge Current vs. Time

(USBH)

USB Voltage (top) (V)

USB Peripheral Current

Consumption (middle) (A)

USB Charge Current (A)

Time

4.0

4.5

5.0

01 2 3 4

0.0

0.5

0.0

0.5

Charge Reduction

Mode Activated

CT Current vs. Temperature

(CT = 0.1µF)

CT Current (nA)

Temperature (°

532

534

536

538

540

542

544

546

548

550

-40 -15 10 35 60 85

Preconditioning

Constant

Current

CT Timeout vs. Temperature

(CT = 0.1µF)

CT Timeout (Hour)

Temperature (°

-40 -15 10 35 60 85

Preconditioning

Constant Current

CT Pin Capacitance vs. Counter Timeout

Capacitance (µF)

Time (hours)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 102030405060

Constant Current Timeout

Preconditioning Timeout

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

Percentage of VVTS vs. Temperature

(ADP or USBH or USBL; VIN = 5V)

Percentage of VVTS (%)

Temperature (°

-40 -15 10 35 60 85

VTS1

VTS2

Total Input Current vs. Output Current

(VBAT = 3.6V)

Input Current (mA)

Output Current (mA)

200

400

600

800

1000

1200

1400

1600

1800

0 200 400 600 800 100

IADP

IUSBH

IUSBL

Transient Response of OUT

When Switching from ADP to BAT

(VADP = 5V ➜ 0V)

Voltage (V)

5OUT

ADP

BAT

Time (500µs/div)

Transient Response of OUT

When Switching from BAT to ADP

(VADP = 0V ➜ 5V)

Voltage (V)

Time (500µs/div)

OUT

ADP

BAT

Transient Response of OUT

When Switching From USBH to BAT

(VUSBH = 5V ➜ 0V; RLOAD = 7.8Ω)

Voltage (V)

Time (500µs/div)

BAT OUT

USBH

Transient Response of OUT

When Switching From BAT to USBH

(VUSBH = 0V ➜ 5V; RLOAD = 7.8Ω)

Voltage (V)

Time (500µs/div)

OUT

BAT USBH

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

Transient Response of OUT

When Switching From USBL to BAT

(VUSBL = 5V ➜ 0V; RLOAD = 50Ω)

Voltage (V)

Time (500µs/div)

OUT

BAT

USBL

Transient Response of OUT

When Switching From BAT to USBL

(VUSBL = 0V ➜ 5V; RLOAD = 50Ω)

Voltage (V)

Time (500µs/div)

OUT

BAT

USBL

Transient Response of OUT

When Switching From USBL to ADP

(VADP = 5V ➜ 0V; RLOAD = 50Ω)

Voltage (V)

Time (500µs/div)

ADP

OUT

USBL

Transient Response of OUT

When Switching From ADP to USBL

(VADP = 0V ➜ 5V; RLOAD = 50Ω)

Voltage (V)

Time (500µs/div)

USBL

ADP

OUT

Transient Response of OUT

When Switching From ADP to USBH

(VADP = 0V ➜ 5V; RLOAD = 7.8Ω)

Voltage (V)

Time (100µs/div)

USBH

OUT

ADP

Transient Response of OUT

When Switching From USBH to ADP

(VADP = 5V ➜ 0V; RLOAD = 7.8Ω)

Voltage (V)

Time (100µs/div)

OUT

USBH

ADP

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Typical Characteristics

Transient Response of OUT When ADP is On

When USBH Switching from On to Off

(VUSBH = 5V ➜ 0V; RLOAD = 7.8Ω)

Voltage (V)

Time (500µs/div)

ADP

USBH

OUT

Transient Response of OUT When ADP is On

When USBH Switching from Off to On

(VUSBH = 0V ➜ 5V; RLOAD = 7.8Ω)

Voltage (V)

Time (500µs/div)

OUT

ADP

USBH

Transient Response of OUT

When Switching From ADP to USBL

(VUSBL = 5V ➜ 0V; RLOAD = 50Ω)

Voltage (V)

Time (500µs/div)

USBL

ADP, OUT

Transient Response of OUT

When Switching From USBL to ADP

(VUSBL = 0V ➜ 5V; RLOAD = 50Ω)

Voltage (V)

Time (500µs/div)

USBL

ADP, OUT

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Functional Description

The AAT3670 is a dual input dynamic battery charge and

power control IC. The dual input capability is designed to

accommodate both AC power adapter and USB port

power sources. In addition, this device also provides

dynamic power control to charge a single cell Li-ion bat-

tery cell and power a system simultaneously.

The device contains separate charge regulation pass

devices to control the charge current or voltage for both

the adapter (ADP) and USB (USB) input power paths.

The AAT3670 also contains three additional load switch-

es to control and route input power to charge the bat-

tery, supply the system load and manage power from the

battery to the system load. This charge control and

switch array permits dynamic charging of the battery cell

and control of power to the system load simultaneously.

When an input power source is applied to the AAT3670,

the device selects the adapter or USB input to provide

power to the system load and charge the battery. If power

is present on both the ADP and USB inputs, the system

will select the ADP input since it provides greater power

levels and charges the battery with a greater current.

Without a valid ADP/USB supply present, the battery will

power the system load as long as the battery voltage is

greater than 2.9V. The battery voltage sense circuit will

disconnect the battery from the load if the cell voltage

falls below 2.9V to protect the battery cell from over-

discharge which would result in shortened battery life.

The system load current drawn from the battery is limited

internally. The AAT3670 precisely regulates battery charge

voltage and current for 4.2V Li-ion battery cells, and the

battery charge current can be programmed up to 1.6A for

Functional Block Diagram

Charge

System

Control

Temperature and

Current Sense

Voltage

Sense

Ref.

Temp.

Sense

Ref.

OUT

BAT

BATS

VTS

GND

CHRUSB

CHRADP

USBSEL

USBLIM

ADPLIM

USBSET

ADPSET

TERM

ENBAT

STAT2STAT1

USB

ADP

Switch 1

Switch 2

Switch 3

ADP Charge

USB Charge

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

ADP charging and up to 0.9A for USB charging. During

battery charge, the AAT3670 pre-conditions (trickle

charge) the battery with lower current when the battery

voltage is less than 2.9V, and it charges the battery in a

constant current mode when the battery voltage is above

2.9V. When the battery voltage rises to 4.2V, the charger

will automatically switch to a constant voltage mode until

the charge current is reduced to the programmed charge

termination current threshold. The internal arrangement

of load switches and charge regulation device also pro-

vide dynamic power sourcing to the system load. If the

system load exceeds the input current supply from the

adapter or USB source, additional current can be sourced

from the battery cell. At all times, the device will manage

distribution of power between the source, the battery and

the system simultaneously in order to support system

power needs and charge the battery cell with the maxi-

mum amount of current possible.

The AAT3670 has a unique internal charge current

reduction loop control that will prevent an input source

from overload. In the case of USB charging from a USB

port VBUS supply, there are two events which need to be

guarded against. The first is charging from a defective or

inadequate USB host supply; the second problem could

arise if the programmed USB charge current plus the

system supply demand through the AAT3670 exceeds

the ability of a given USB port. In either case, the

AAT3670 charge reduction (CHR) loop will activate when

the input source to the USB input drops below the VCHR_TH

threshold of 4.5V. The CHR loop will automatically reduce

the charge current to the battery until the supply voltage

recovers to a point above the VCHR_TH threshold. The CHR

loop protection system also operates in the adapter input

mode with a 4.6V VCHR_TH threshold. This protects the

charger, system and source supply in the event an

adapter or power source does not meet the ADP charg-

ing mode specification. In USB or adapter mode charg-

ing, the CHR system will permit the charging of a battery

cell with the maximum possible amount of charge cur-

rent for any given source fault condition.

During battery charging, the device temperature will

rise. In some cases with adapter (ADP) charging, the

power dissipation in the device may cause the junction

temperature to rise to close to its thermal shutdown

threshold. In the event of an internal over-temperature

condition caused by excessive ambient operating tem-

perature or excessive power dissipation condition, the

AAT3670 enables a digitally controlled thermal loop sys-

tem that will reduce the charging current to prevent the

device from thermal shutdown. The digital thermal loop

will maintain the maximum possible battery charging

current for the given set of input to output power dissi-

pation and ambient temperature conditions. The digital

thermal loop control is dynamic in the sense that it will

continue to adjust the battery charging current as oper-

ating conditions change. The digital thermal loop will

reset and resume normal operation when the power dis-

sipation or over-temperature conditions are removed.

Battery temperature and charge state are fully moni-

tored for fault conditions. In the event of an over-volt-

age, over-current, or over-temperature failure, the

device will automatically shut down, thus protecting the

charging device, control system, and the battery under

charge. In addition to internal charge controller thermal

protection, the AAT3670 also provides a temperature

sense feedback function (VTS/TS pins) from the battery

to shut down the device in the event the battery exceeds

its own thermal limit during charging. All fault events are

reported to the user by two simple status LEDs.

Charging Operation

The AAT3670 has four basic modes for the battery

charge cycle regardless of which charge input function is

selected, either the adapter input or USB input: pre-

conditioning/trickle charge, constant current fast charge,

constant voltage, and end of charge/sleep mode.

Battery Preconditioning

Before the start of charging, the AAT3670 checks sev-

eral conditions in order to assure a safe charging envi-

ronment. The input supply must be above the minimum

operating voltage, or under-voltage lockout threshold

(VUVLO), for the charging sequence to begin. Also, the cell

temperature, as reported by a thermistor connected to

the TS pin from the battery, must be within the proper

window for safe charging. When these conditions have

been met and a battery is connected to the BAT pin, the

AAT3670 checks the state of the battery via the battery

voltage sensing (BATS) pin. If the cell voltage is below

the preconditioning voltage threshold (VMIN), the AAT3670

begins preconditioning the cell.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

The battery preconditioning trickle charge current is

equal to the fast charge constant current divided by 10

for the adapter and USB high input modes. For example,

if the programmed fast charge current is 500mA, then

the preconditioning mode (trickle charge) current will be

50mA. In the USB low charging mode, the precondition-

ing current is set to the programmed fast charge current

divided by two. Cell preconditioning is a safety precau-

tion for a deeply discharged battery and also aids in

limiting power dissipation in the charge control pass

transistor when the voltage across the device is at the

greatest potential.

Fast Charge/Constant Current Charging

Battery cell preconditioning continues until the voltage

measured by the battery sense (BATS) pin exceeds the

preconditioning voltage threshold (VMIN). At this point,

the AAT3670 begins constant-current charging fast

charging phase. The fast charge constant current (ICC)

level is determined by the charge mode (ADP, USBH or

USBL) and is programmed by the user via the RADPSET and

RUSBSET resistors. The AAT3670 remains in constant cur-

rent charge mode until the battery reaches the voltage

regulation point, VBAT_EOC.

Constant Voltage Charging

The charge control system transitions to a regulated con-

stant voltage charging mode when the battery voltage

reaches output charge regulation threshold (VBAT_EOC) dur-

ing constant current fast charge phase. The regulation

voltage level is factory programmed to 4.2V (±1%). The

charge current in the constant voltage mode drops as the

battery cell under charge reaches its maximum capacity.

End of Charge Cycle Termination

and Recharge Sequence

When the charge current drops to the user programmed

charge termination current at the end of the constant volt-

age charging phase, the device terminates charging and

enters the sleep state. The charger will remain in the sleep

state until the battery voltage decreases to a level below

the battery recharge voltage threshold (VRCH). The charge

termination current is programmed via the RTERM resistor.

When the input supply is disconnected, the charger also

automatically enters power-saving sleep mode. Only

consuming an ultra-low 1μA in sleep mode, the AAT3670

minimizes battery drain when not charging. This feature

is particularly useful in applications where the input sup-

ply level may fall below the usable range of the charge

reduction control or under-voltage lockout level. In such

cases where the AAT3670 input voltage drops, the

device will enter the sleep mode and automatically

resume charging once the input supply has recovered

from its fault condition.

Constant Current

Charge Phase

Constant Voltage

Charge Phase

Preconditioning

Trickle Charge

Phase

End of Charge Voltage

Constant Current Mode

Voltage Threshold

Regulated Current

Trickle Charge

I = Max CC

Charge Termination Current

(4.2V)

(2.9V)

Figure 1: Current vs. Voltage Profile During Charging Phases.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Switch

UVLO

VP> VUVLO

Power On

Reset

Fault

Condition

Monitor

OV, OT,

Battery Temp.

Sense

VTS1 < TS < VTS2

Preconditioning

Test

VMIN > VBAT

Current Phase

Test

VEOC > VBAT

Voltage Phase

Test

IBAT > ITERM

Charge

Complete

Recharge Test

VRCH > VBAT ?

Sleep

Mode

Thermal

Loop Enable

Thermal Loop

Current Reduction

Device

Temp. Monitor

TJ> 110degC

Input Voltage

Level Test

VADP < VCHR_TH

Constant Current

Charging Mode

Constant Voltage

Charge Mode

Voltage

Regulation

Enable

Low Current

Conditioning

Charge

Battery

Temperature

Fault

Shutdown

Mode

Charge Timer

(Enable on

Charger reset)

Yes

Charge Reduction

Mode

Yes

Expire

Set

Enable

Dynamic Charge

VEN_BAT > VEN

Current Limit

Test

IOUT > ILIM

IOUT + IBAT > ILIM ?

Connect

ADP to BAT

and OUT

Power

Reduce Charging

Current to BAT

Yes

YesYes

NoYes

Yes

Figure 2: AAT3670 Operational Flow Chart.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Applications Information

AC Adapter/USB System Power Charging

Adapter Input Mode

In the adapter mode, constant current charge levels up

to 1.6A may be programmed by the user. The AAT3670

system control will always select the adapter input over

the USB supply input when ever voltage is present on

the ADP pin. The ADP input will operate over a range

from 4.35V to 5.5V.

The constant fast charge current for the adapter input

mode is set by the RADPSET resistor connected between the

ADPSET pin and ground. The battery preconditioning or

trickle charge current is fixed at 10% of the programmed

fast charge constant current level. Refer to Table 2 for

recommended RADPSET values for a desired constant cur-

rent charge level. Battery charging states will be indi-

cated via the STAT1 and STAT2 display LEDs. Please

refer to the Battery Charge Status Indication discussion

for further details on data reporting.

ADP Charge Reduction

Under normal operation, the AAT3670 should be operated

from an adapter power source with a sufficient capacity

to supply the desired constant charge current plus any

additional load which may be placed on the source by the

operating system. In the event that the power source to

the ADP pin is unable to provide the programmed fast

charge constant current, or if the system under charge

must also share supply current with other functions, the

AAT3670 will automatically reduce the ADP fast charge

current level to maintain the integrity of the source sup-

ply, power the operating system, and charge the battery

cell with the remaining available current.

The ADP charge reduction system becomes active when

the voltage on the ADP input falls below the ADP charge

reduction threshold (VCHRADP), which is preset to 4.6V.

Should the input supply drop below the VCHRADP threshold,

the charge reduction system will reduce the fast charge

current level in a linear fashion until the voltage sensed

on the ADP input recovers to a point above the charge

reduction threshold voltage. The ADP charge reduction

threshold (VCHRADP) may be externally set to a value other

than 4.6V by placing a resistor divider network between

the ADP pin and ground with the center connected to the

CHRADP pin. The ADP charge reduction feature may be

disabled by shorting the CHRADP pin directly to the ADP

input pin.

The following equation may be used to approximate the

ADP charge reduction threshold above or below 4.5V:

Eq. 1:

VADPCHR = 2.0V

(R12/[R12 + R11])

where R11 and R12 < 500k.

850k

650k

R11

R12

VCHR = 2.0V

VADP ADP

CHRADP

Figure 3: Internal Equivalent Circuit for the

CHRADP Pin.

Adapter Input Charge Inhibit and Resume

The AAT3670 has an under-voltage lockout (UVLO) and

power on reset feature to protect the charger IC in the

event the input supply to the adapter pin drops below

the UVLO threshold. Under a UVLO condition, the char-

ger will suspend the charging process. When power is

re-applied to the adapter pin or the UVLO condition

recovers, the system charge control will asses the state

of charge on the battery cell and will automatically

resume charging in the appropriate mode for the condi-

tion of the battery.

USB Input Mode

The AAT3670 provides an input for intelligent USB charg-

ing. When no voltage is present on the adapter input pin,

the charge controller will automatically switch to accept-

ing power from the USB input. The USB charge mode

provides two programmable fast charge levels, USB high

(USBH) and USB low (USBL). The USBH mode can be set

as high as 900mA; however for most applications utiliz-

ing a USB port as the source supply, 500mA is the typical

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

default USBH value and USBL is subsequently set for

100mA. In the USBL fast charge mode, the constant

charging current is set to 20 percent of the programmed

USBH. More simply put, the USBL low fast charge level

= USBH divided by five. The USBH or USBL modes may

be externally selected by USB select pin (USBSEL).

In the USBH mode, the battery cell preconditioning or

trickle charge current is fixed at 10 percent of the pro-

grammed fast charge constant current. In the USBL mode,

the trickle charge current is only reduced to 50 percent of

the programmed fast charge constant current level.

When the USBSEL pin is connected to a logic high level,

the USBH level will be active. Conversely, when USBSEL

is pulled to a logic low level (ground) the USBL level will

be used for fast charging. Refer to Table 2 for the recom-

mended RUSBSET value to program the desired USB input

constant current charge levels.

USB Charge Reduction

In many instances, product system designers have an

issue of not knowing the real properties of a potential

USB port to be used to supply power to the battery char-

ger. Typical powered USB ports commonly found on

desktop and notebook PCs should supply up to 500mA.

In the event a USB port being used to supply the charger

is unable to provide the programmed fast charge cur-

rent, or if the system under charge must also share sup-

ply current with other functions causing an overload to

the USB port, the AAT3670 will automatically reduce

USB fast charge current to maintain port integrity and

protect the host system.

The USB charge reduction system becomes active when

the voltage on the USB input falls below the USB charge

reduction threshold (VCHRUSB), which is typically 4.5V.

Regardless of which USB charge function is selected

(USBH or USBL), the charge reduction system will

reduce the fast charge current level in a linear fashion

until the voltage sensed on the USB input recovers

above the charge reduction threshold voltage. The USB

charge reduction threshold (VCHRUSB) may be externally

set to a value lower than 4.5V by placing a resistor

divider network between VUSB and ground with the cen-

ter connected to the CHRUSB pin. The USB charge

reduction feature may be disabled by shorting the

CHRUSB pin directly to the USB input pin.

The following equation may be used to approximate a

USB charge reduction threshold below 4.5V:

Eq. 2:

VUSBCHR = 2.0V

(R2/[R2 + R1])

where R1 and R2 < 1M

1.0 M

800k

VCHR = 2.0V

VUSB USB

CHRUSB

Figure 4: Internal Equivalent Circuit for the

CHRUSB Pin.

USB Input Charge Inhibit and Resume

The AAT3670 under-voltage lockout (UVLO) and power-

on reset feature will function when the USB input pin

voltage level drops below the UVLO threshold. At this

point the charger will suspend charging. When power is

re-applied to the USB pin or the UVLO condition recovers,

the system charge control will assess the state of charge

on the battery cell and will automatically resume charging

in the appropriate mode for the condition of the battery.

End of Charge Termination

The AAT3670 provides a user-programmable charge ter-

mination current at the end of the charge cycles. When

the battery cell voltage as sensed by the BATS pin

reaches 4.2V, the charge control will transition from con-

stant current fast charge mode to constant voltage

mode. In constant voltage mode, the battery cell voltage

will be regulated at 4.2V. The charge current will drop as

the battery reaches its full charge capacity. When the

charge current drops to the programmed end of charge

(EOC) current, the charge cycle is complete and the

charge controller terminates the charging process.

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

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

The charge termination current is user programmed by

the value of RTERM, which is connected between the TERM

pin and ground. Use the values listed in Table 1 to set

the desired charge termination current. The programmed

charge termination current will remain at the same set

level regardless of which fast charge ADP, USBH or USBL

constant current mode is selected.

ITERM (mA) RTERM (kW)

320 11.0

174 21.0

125 30.9

95 41.2

77 51.1

64 61.9

58 71.5

50 80.6

49 90.9

42 100.0

37 110.0

Table 1: Charge Termination Current

Programming Resistor Values.

If the desired end of charge termination current level is

not listed in Table 1, the TERM resistor value may be

calculated by the following equation:

For the Adapter input mode:

⎛⎞

⎝⎠

RTERM = K · VTERM

ICC

Where:

K = KI_TERM = 2000

VTERM = 2V

ICC = Fast charge constant current

The constants K and VTERM are specified in the Typical

Characteristics section of this datasheet.

The end-of-charge termination current function can be

disabled by pulling the TERM pin high via connecting the

TERM pin to the BAT pin. In this state, the end-of-charge

function will be disabled and the battery will float charge

in the constant voltage mode indefinitely or until the cell

voltage is brought below the constant voltage threshold.

System Power Output

The power to the system is supplied via the OUT pin. OUT

will source power from either the ADP or USB inputs when

an external power source is applied. When the battery

charging function is complete and the charging power

source is removed, the system will be powered from the

battery via Load Switch 3, referring to the AAT3670 block

diagram. The maximum current that can be supplied from

the ADP or USB inputs to a system load is bounded by the

user programmed ADPLIM and USBLIM level. If the cur-

rent consumption from the system load exceeds that of

the ADP or USB input sources, the IC will draw current

from the battery to make up the difference as long as the

battery cell voltage remains above 2.9V. Power from the

battery to the OUT pin is controlled by the ENBAT func-

tion. When the ENBAT is disabled the leakage current

from the battery to the load is less than 1μA.

Battery Connection and

Battery Voltage Sensing

Battery Connection

The single cell Li-ion battery should be connected

between the BAT pin and ground. The internal load

switching network will connect the battery to the system

load and apply the charging current.

Battery Voltage Sensing

The BATS pin is provided to employ an accurate voltage

sensing capability to measure the terminal voltage at the

battery cell being charged. This function reduces mea-

sured battery cell voltage error between the battery

terminal and the charge control IC. The AAT3670 charge

control circuit will base charging mode states upon the

voltage sensed at the BATS pin. The BATS pin must be

connected to the battery terminal for correct operation.

If the battery voltage sense function is not needed, the

BATS pin should be terminated directly to the BAT pin. If

there is concern of the battery sense function inadver-

tently becoming an open circuit, the BATS pin may be

terminated to the BAT pin using a 10k resistor. Under

normal operation, the connection to the battery terminal

will be close to 0; if the BATS connection becomes an

open circuit, the 10k will provide feedback to the BATS

pin from the BAT connection will a 1mV or less loss in

sensed voltage accuracy.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Enable

The AAT3670 provides an enable function to control the

charger IC on and off. The enable (EN) pin is active high.

When pulled to a logic low level, the AAT3670 will be

shut down and forced into the sleep state. Charging will

be halted regardless of the battery voltage or charging

state. When the device is re-enabled, the charge control

circuit will automatically reset and resume charging

functions with the appropriate charging mode based on

the battery charge state and measured cell voltage.

Battery Enable

Since the AAT3670 provides battery power switching as

well as charging function, a battery enable pin (ENBAT)

is provided so the power from the battery via the BAT

pin to the OUT pin may be externally controlled. The

ENBAT function allows the user to control power to the

systems regardless of charging state, input power

source, or charge enable (EN) state.

It may be desirable for some system designs to discon-

nect the battery from the load during charging. This may

be accomplished by pulling the ENBAT pin low, while the

device is enabled for charging (EN high).

Programming Charge Current

The fast charge constant current charge level for both

adapter and USB input modes are programmed with set

resistors placed between the ADPSET or USBSET pins

and ground. The accuracy of the fast charge constant

current and the preconditioning trickle charge current

are dominated by the tolerance of the set resistor used.

For this reason, 1% tolerance metal film resistors are

recommended for this set resistor function.

Fast charge constant current levels from 50mA to 1.6A

may be set by selecting the appropriate resistor value

from Table 2. The RADPSET resistor should be connected

between the ADPSET pin and ground.

The USB input fast charge constant current charge con-

trol provides up to 900mA of charge current and is set

in the USBH mode. The USBSEL pin is used to select the

high or low charge current levels in the USB charge

mode. When the USBSEL pin is pulled to a voltage level

above the VUSBSEL(H) threshold, the USBH current level will

be selected. Conversely, this pin should be pulled below

the VUSBSEL(L) threshold to enable the USBL charge level;

the USBL charge current will be set to 20% of the set

USBH level. For typical USB charging applications, the

USBH and USBL functions are fixed for 500mA and

100mA USB fast charge levels. However, the charge

level of USBH may be set from 50mA to 900mA and

USBL will in turn be fixed at 20% of the USBH level

depending upon the system design requirements for a

given USB charge application. Refer to Table 2 and

Figure 5 for recommended RUSBSET values.

ICC

(mA) ADP

RSET (kW) USBH

RSET (kW) USBL

RSET (kW)

50 1300 750 150

90 681 453 80.6

100 590 383 71.5

150 412 249 47.5

200 309 187 34.8

250 249 150

300 205 124

400 154 90.9

500 121 71.5

650 93.1 54.9

800 73.2 43.2

900 64.9 38.3

1000 57.6

1200 48.7

1500 38.3

1600 34.8

Table 2: RSET Values.

IFASTCHARGE (mA)

RSET (kΩ

)

200

400

600

800

1000

1200

1400

1600

1800

10 100 1000 10000

ADP

USBL

USBH

Figure 5: Fast Charge Current vs. Set Resistor

(VIN = 5V; VBAT = 3.5V).

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

If the desired current charge current level is not listed in

Table 2, the ADPSET and USBSET resistor values may be

calculated by the following equations:

For the Adapter input mode:

⎛⎞

⎝⎠

RADPSET = K · VADPSET

ICC

Where:

K = KI_CCADP = 29300

VADPSET = 2V

ICC = Fast Charge Constant Current

For the USB input mode:

⎛⎞

⎝⎠

RUSBSET = K · VUSBSET

ICC

Where:

K = KI_CCUSBH = 17900 (USBH)

K = KI_CCUSBL = 3600 (USBL)

VUSBSET = 2V

ICC = Fast Charge Constant Current

All constants K and VADP/USBSET are specified in the Typical

Characteristics section of this datasheet.

Protection Circuitry

Thermal Loop Control

Due to the integrated nature of the linear charging con-

trol pass devices for both the adapter and USB modes, a

special thermal loop control system has been employed

to maximize charging current under all operating condi-

tions. The thermal management system measures the

internal circuit die temperature and reduces the charge

current when the device exceeds a preset internal tem-

perature control threshold. Once the thermal loop con-

trol becomes active, the constant charge current is ini-

tially reduced by a factor of 0.44.

The initial thermal loop current can be estimated by the

following equations:

In ADP mode: ITLOOP = ICCADP · 0.44

In USB mode: ITLOOP = ICCUSBH · 0.44

The thermal loop control re-evaluates the internal die

temperature every three seconds and adjusts the fast

charge current back up in small steps up to the full fast

charge current level or until an equilibrium current is

discovered and maximized for the given ambient tem-

perature condition. In this manner, the thermal loop

controls the system charge level. The AAT3670 will

always provide the highest possible level of constant cur-

rent in the fast charge mode for any given ambient tem-

perature condition.

Programmable Watchdog Timer

The AAT3670 contains a watchdog timing circuit which

operates only in adapter charging mode. Typically a

0.1μF ceramic capacitor is connected between the CT pin

and ground. When a 0.1μF ceramic capacitor is used, the

device will time a shutdown condition if the trickle

charge mode exceeds 45 minutes. When the device tran-

sitions to the trickle charge to the fast charge constant

current mode and then to the constant voltage mode,

the timing counter is reset and will time out after 3 hours

for each mode.

Summary for a 0.1μF used for the timing capacitor:

Trickle Charge (TC) time out = 45 minutes

Fast Charge Constant Current (CC) time out = 3 hours

Constant Voltage (VC) mode time out = 3 hours

The CT pin is driven by a constant current source and will

provide a linear response to increases in the timing

capacitor value. Thus, if the timing capacitor were to be

doubled from the nominal 0.1μF value, the time out time

of the CC + CV modes would be doubled. The corre-

sponding trickle charge time out time would be the com-

bined CC + VC time divided by 8.

If the programmable watchdog timer function is not

needed it may be disabled the terminating the CT pin to

ground. The CT pin should not be left floating or un-

terminated; this will cause errors in the internal timing

control circuit.

The charge timer control will suspend the timing count in

any given mode in the event a fault condition occurs.

Such fault conditions include digital thermal loop charge

current reduction, ADP or USB charge reduction, battery

temperature fault, and battery current sharing with the

output during the charging cycle. When the fault condi-

tion recovers, the counter will resume the timing func-

tion. The charge timer will automatically reset when the

AAT3670 enable pin is reset or cycled off and on.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

The constant current provided to charge the timing

capacitor is very small and this pin is susceptible to

noise and changes in capacitance value. Therefore, the

timing capacitor should be physically located on the

printed circuit board layout as close as possible to the CT

pin. Since the accuracy of the internal timer is deter-

mined by the capacitance value, a 10% tolerance or

better ceramic capacitor is recommended. Ceramic

capacitor materials such as X7R and X5R type are a

good choice for this application.

Over-Current Protection

The AAT3670 provides over-current protection to both

the battery and system output modes for both the ADP

and USB input sources.

The over-current protection threshold is user program-

mable and independent from the constant charge current

setting. The set resistor RADPLIM is connected between the

ADPLIM pin and ground to program the ADP power path

current limit up to 1.6A. The set resistor RUSBLIM is con-

nected between the USBLIM pin and ground to program

the USB power path current limit up to 900mA. For both

the ADP and USB charge paths, the programmed constant

current fast charge level may not exceed the respective

ADPLIM and USBLIM set points. Refer to Table 3 for the

ADPLIM and USBLIM programming resistor values.

ICC (mA) RADPLIM (kW) RUSBLIM (kW)

50 1300 750

90 681 453

100 590 383

150 412 249

200 309 187

250 249 150

300 205 124

400 154 90.9

500 121 71.5

650 93.1 54.9

800 73.2 43.2

900 64.9 38.3

1000 57.6

1200 48.7

1500 38.3

1600 34.8

Table 3: Current Limit Programming

Resistor Values.

If the desired charge current limit level is not listed in

Table 3, the ADPLIM and USBLIM set resistor values may

be calculated by the following equations:

For the Adapter input mode:

⎛⎞

⎝⎠

RADPLIM = K · VADPLIM

ICC

Where:

K = KI_LIM_ADP = 27800

VADPLIM = 2V

ICC = Fast Charge Constant Current

For the USB input mode:

⎛⎞

⎝⎠

RUSBLIM = K · VUSBLIM

ICC

Where:

K = KI_LIM_USBH = 17600 (USBH)

K = KI_LIM_USBL = 3500 (USBL)

VUSBLIM = 2V

ICC = Fast Charge Constant Current

All constants K and VADP/USBLIM are specified in the Typical

Characteristics section of this datasheet.

Over-Voltage Protection

An over-voltage event is defined as a condition where

the voltage on the BATS pin exceeds the maximum bat-

tery charge voltage and is set by the over-voltage pro-

tection threshold (VOVP). If an over-voltage condition

occurs, the AAT3670 charge control will shutdown the

device until voltage on the BATS pin drops below the

over-voltage protection threshold (VOVP). The AAT3670

will resume normal charging operation once the battery

over-voltage condition is removed. During an over-volt-

age event, the STAT2 LED will report a system fault.

Over-Temperature Shutdown

The AAT3670 has a thermal protection control circuit

which will shut down charging functions should the inter-

nal die temperature exceed the preset thermal limit

threshold.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Battery Temperature Fault Monitoring

In the event of a battery over-temperature condition, the

charge control will turn off the internal charge path regu-

lation device and report the fault condition via the STAT2

display LED. After the system recovers from a tempera-

ture fault, the device will resume charging operation. The

AAT3670 checks battery temperature before starting the

charge cycle, as well as during all stages of charging.

Typically, batteries employ the use of a negative tem-

perature coefficient (NTC) thermistor that is integrated

into the battery package. Most commonly used NTC

thermistors used in battery packs are approximately

10k at room temperature (25°C). However, the

AAT3670 TS pin, in conjunction with the VTS pin, permits

the use of almost any value of NTC thermistor.

There are two pins associated with the battery tempera-

ture sensing function, TS and VTS. The battery pack

thermistor should be connected between the TS pin and

ground. The VTS pin is provided to allow the user to

program battery temperature sense thresholds depend-

ing upon the value of the NTC thermistor used in a given

battery pack. A resistor (RT) connected between the VTS

pin and the TS pin will set a bias for the NTC thermistor

function. The TS function has been designed such that a

default NTC thermistor value of 10k will then require a

10k resistor for RT

. To determine the actual operating

temperature window for the the NTC thermistor and the

TS pin, one must first specify the NTC thermistor to be

used, then refer to the thermistor datasheet to deter-

mine its characteristics.

The internal battery temperature sensing system is com-

prised of two comparators which establish a voltage

window for safe operation. The thresholds for the TS

operating window are bounded by the TS1 and TS2

specifications. Referring to the electrical characteristics

table in this datasheet, the TS1 threshold = 0.30 · VVTS

and the TS2 threshold = 0.72 · VVTS. The VTS pin is

capable of sourcing up to 2mA.

If the use of the battery temperature sense function is

not required, it may be disabled by disconnecting the

VTS pin from the TS pin and terminating the TS pin to

ground. The VTS pin can be left floating.

Battery Charge Status Indication

The AAT3670 indicates the status of the battery under

charge using two status LED driver outputs. These two

LEDs can indicate simple functions such as no battery

charge activity, battery charging, charge complete and

charge fault.

Status Indicator Display

System charging status may be displayed using one or

two LEDs in conjunction with the STAT1 and STAT2 pins

on the AAT3670. These two pins are simple switches to

connect the status LED cathodes to ground. It is not nec-

essary to use both display LEDs if a user simply wants to

have a single lamp to show “charging” or “not charging”.

This can be accomplished by using the STAT1 pin and a

single LED. Using two LEDs and both STAT pins simply

gives the user more information for the various charging

states. Refer to Table 4 for LED display definitions.

NTC T

Battery Cold Faul

Battery Hot Fault

VTS

0.72 · VVTS

0.30

· VVTS

Figure 6: Battery Temperature Sense Circuit.

NTC T

Battery Cold Faul

Battery Hot Fault

VTS

ADJ

0.72V

0.30V +

Figure 7: Battery Temperature Sense Circuit with

Externally Adjusted Window Threshold.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

The LED anodes should be connected to USB, ADP, BAT,

or OUT depending upon the system design require-

ments. The LEDs should be biased with as little current

as necessary to create reasonable illumination. A ballast

resistor should be placed between the status LED cath-

odes and the STAT1/2 pins. LED current consumption

will add to the over thermal power budget for the device

package, hence it is good reason to keep the LED drive

current to a minimum. 2mA should be sufficient to drive

most common low cost green or red LEDs. It is not rec-

ommended to exceed 8mA for driving an individual sta-

tus LED. The required ballast resistor value can be esti-

mated using the following formulas:

For connection to the adapter supply:

Eq. 3:

RB(STAT1/2) = (VADP - VF(LED))

ILED(STAT1/2)

Example: RB(STAT1) = (5.5V - 2.0V) 2mA = 1.75k

Note: Red LED forward voltage (VF) is typically 2.0V @

2mA.

For connection to the USB supply:

Eq. 4:

RB(STAT1/2) = (VUSB - VF(LED))

ILED(STAT1/2)

Example: RB(STAT2) = (5.0V - 3.2V) 2mA = 900

Note: Green LED forward voltage (VF) is typically 3.2V @

2mA.

For connection to the BAT supply:

Eq. 5:

RB(STAT1/2) = (VBAT - VF(LED))

ILED(STAT1/2)

Example: RB(STAT2) = (3.6V - 3.2V) 2mA = 200

Note: Green LED forward voltage (VF) is typically 3.2V @

2mA.

No Battery Present Indication

If the AAT3670 charger IC is powered and enabled from

either the ADP or USB input, yet no battery is connected

to the BAT and BATS pins, the STAT1 LED will flash at a

1Hz rate with an approximate 40% duty cycle when a

10μF capacitor is connected between the BAT pin and

ground. The flash rate of the STAT1 LED can be adjusted

by changing the value of the battery output (BAT pin)

capacitor. If the capacitor value is increased above 20μF,

the no battery detect flashing function will be defeated.

The flash rate of the no battery detect function may be

approximated by the following equation:

Eq. 6:

C = I · T

Where:

C = Capacitor value

I = Start up source current from the BAT pin = 5μA

V = Difference voltage between the end of charge volt-

age and the battery recharge threshold = 0.2V

T = Rate of LED flashing in seconds

Thermal Considerations

The AAT3670 is available in a 4x4mm 24-pin QFN pack-

age which can provide up to 2.0W of power dissipation

when it is properly bonded to a printed circuit board, but

can achieve a maximum thermal resistance of 37°C/W

with printed circuit board enhancement. Many consider-

ations should be taken into account when designing the

printed circuit board layout as well as the placement of

the charger IC package in proximity to other heat gen-

erating devices in a given application design. The ambi-

Event Description STAT1

End of Charge (TERM Current Reached in CVM), Battery OV, Timeout, or Charge Disabled OFF

No Battery (With Charge Enabled) Flash (1Hz, 40% duty)

Battery Charging (Including Suspended Charging Due to Battery OT/UT, or Device OT ) ON

Event Description STAT2

Charge Disabled, No Battery, End of Charge, or Charging Without Faults OFF

Faults (Battery OV/OT/UT, or Device OT) or Timeout ON

Table 4: LED Status Indicator (STATx Pulled Up to a Voltage Source with Resistors and LED).

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

ent temperature around the charger IC will also have an

effect on the thermal limits of a battery charging applica-

tion. The maximum limits that can be expected for a

given ambient condition can be estimated by the follow-

ing discussion:

First, the maximum power dissipation for a given situa-

tion should the calculated:

Eq. 7:

PD = [(VIN - VBAT) · ICC + (VIN · IOP) + (IOUT2 · RDS(ON))

Where:

PD = Total power dissipation by the device

VIN = either VADP or VUSB, depending on which mode is

selected

VBAT = Battery voltage as seen at the BAT pin

ICC = Maximum constant fast charge current pro-

grammed for the application

IOP = Quiescent current consumed by the charger IC

for normal operation

IOUT = Load current to system from the OUT pin

RDS(ON) = On-resistance of load switch between ADP or

USB and OUT

Next, the maximum operating ambient temperature for

a given application can be estimated based on the ther-

mal resistance of the 4x4 QFN package when sufficiently

mounted to a PCB layout and the internal thermal loop

temperature threshold.

Eq. 8: TA = TJ - (θJA · PD)

Where:

TA = Ambient temperature in °C

TJ = Maximum device junction temperature below the

thermal loop threshold

PD = Total power dissipation by the device

JA = Package thermal resistance in °C/W

Example:

For an application where the fast charge current for the

adapter mode is set to 1A, VADP = 5.0V, and the worst-

case battery voltage at 3.0V with the system load dis-

abled, what is the maximum ambient temperature where

the thermal limiting will become active?

Given:

VADP = 5.0V

VBAT = 3.0V

ICC = 1A

IOP = 0.75mA

TJ = 110°C

JA = 37°C/W

IOUT = 0

RDS(ON) = 0.4

Using Equation 7, calculate the device power dissipation

for the stated condition:

Eq. 9:

PD = (5.0V - 3.0V)(1A) + (5.0V · 0.75mA) + (02 · 0.4Ω)

= 2.00375W

The maximum ambient temperature before the AAT3670

thermal loop becomes active can now be calculated

using Equation 8:

Eq. 10:

TA = 110°C - (37°C/W · 2.00375W)

= 35.86°C

Therefore, under the stated conditions for this worst-

case power dissipation example, the AAT3670 will enter

the thermal loop and lower the fast charge constant cur-

rent when the ambient operating temperature rises

above 35.86°C.

Capacitor Selection

Input Capacitor

In general, it is good design practice to place a decoupling

capacitor between the ADP and USB pins and ground. An

input capacitor in the range of 1μF to 22μF is recom-

mended. If the source supply is unregulated, it may be

necessary to increase the capacitance to keep the input

voltage above the under-voltage lockout threshold during

device enable and when battery charging is initiated.

If the AAT3670 adapter input is to be used in a system

with an external power supply source, such as a typical

AC-to-DC wall adapter, then a CIN capacitor in the range of

10μF should be used. A larger input capacitor in this appli-

cation will minimize switching or power bounce effects

when the power supply is “hot plugged” in. Likewise, a

10μF or greater input capacitor is recommended for the

USB input to help buffer the effects of USB source power

switching, noise and input cable impedance.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Output Capacitor

The AAT3670 only requires a 1μF ceramic capacitor on

the BAT pin to maintain circuit stability. This value

should be increased to 10μF or more if the battery con-

nection is made any distance from the charger output. If

the AAT3670 is to be used in applications where the bat-

tery can be removed from the charger, such as with the

case with desktop charging cradles, an output capacitor

greater than 10μF, but less than 20μF, may be required

to retard the device from cycling on and off when no

battery is present.

Printed Circuit Board

Layout Considerations

For the best results, it is recommended to physically place

the battery pack as close as possible to the AAT3670 BAT

pin as possible. To minimize voltage drops on the PCB,

keep the high current carrying traces adequately wide.

For maximum power dissipation of the AAT3670 QFN

package, the metal substrate should be solder bonded to

the board. It is also recommended to maximize the sub-

strate contact to the PCB ground plane layer to further

increase local heat dissipation. Refer to the AAT3670

evaluation board for a good layout example.

USBSEL

OUT

BAT

ADP

VTS

ADPSET

USBSET

GND

TERM

STA T 2

ST AT 1

BATS

CHRADP

ADPLIM

USBLIM

N/C

USB

CHRUSB

ENBAT

AAT3670

100k

R2 R31R41

34.8k

39.2k

57.6k

71.5k

R10

R11

R121

R131

D1 D2

1 2 3

USBSEL

ENBAT

ENABLE

BAT

OUT

ADP

USB

1 2 3 4 5

USB

10μF

0.01μF

10μF

SOT-23

D3A

D3B

Figure 8: AAT3670 Evaluation Board Schematic.

1. Not populated (Open) on the Evaluation Board

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

Figure 9: AAT3670 Evaluation Board Top Side Layout.

Figure 10: AAT3670 Evaluation Board Bottom Side Layout.

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AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

AAT3670

DATA SHEET

1.6A Dynamic Battery Charger and Power Manager

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Customers are responsible for their products and applications using Skyworks products, which may deviate from published speciﬁ cations as a result of design defects, errors, or operation of products outside of pub-

lished parameters or design speciﬁ cations. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product

design, or damage to any equipment resulting from the use of Skyworks products outside of stated published speciﬁ cations or parameters.

Skyworks, the Skyworks symbol, and “Breakthrough Simplicity” are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for

identiﬁ cation purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference.

Ordering Information

Package Marking1Part Number (Tape and Reel)2

QFN44-24 TFXYY AAT3670ISK-4.2-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 Information3

QFN44-24

4.000 ±

0.050

2.7 ±

0.05

0.300 ´ 45°

Pin 1 Dot By Marking

4.000 ±

0.050 2.7 ±

0.05

0.5 BSC 0.4 ±

0.05

0.305 ±

0.075

0.900 ±

0.050

0.025 ±

0.025

0.214 ±

0.036

Pin 1 Identification

R0.030Max

712

19 24

Top View Bottom View

Side View

All dimensions in millimeters.

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.

Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Skyworks:

AAT3670ISK-4.2-T1