AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
1
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
General Description
The AAT2868 is a low-noise, constant-frequency charge
pump DC/DC converter that uses a dual-mode load switch
(1x) and fractional (1.5x) conversion to maximize effi-
ciency for white LED Content Adaptive Brightness Control
(CABC) applications. The AAT2868 is capable of driving 4
white LEDs at a total 124mA from a 2.7V to 5.5V input.
The current sinks may be operated individually or in par-
allel for driving higher-current LEDs. A low external parts
count (two 1µF flying capacitors and two small 1µF capac-
itors at IN and OUTCP) makes the AAT2868 ideally suited
for small battery-powered applications. The AAT2868 also
includes two 150mA low dropout (LDO) linear regulators
as additional power supplies for display and related cam-
era power. The LDO voltage is also programmable.
Skyworks’ Advanced Simple Serial Control™ (AS2Cwire™)
serial digital input is used to enable, disable and set the
maximum LED current to one of 32 levels for the LEDs.
The current ranges from 31mA to 0.4mA. An external
PWM input is adopted to dim the LED current from 100%
to 1% of the maximum LED current by varying the PWM
duty cycle with frequencies up to 100kHz. To eliminate
flicker or noise associated with PWM control, the input
PWM signal is filtered to provide a steady state output
current.
Each output of the AAT2868 is equipped with built-in
protection for short-circuit and auto-disable for load
short-circuit conditions. The soft-start circuitry prevents
excessive inrush current at charge pump start-up and
mode transitions.
The AAT2868 is available in the Pb-free, space-saving
TQFN3.0x2.2-18L package, and operates over the -40°C
to 85°C ambient temperature range.
Features
•2.7V to 5.5V Supply Voltage Range
•Charge Pump for LED Driver
▪ Dual Mode 1x/1.5x
▪ Drives Up to 4 LEDs with up to 31mA each
▪ Linear LED Output Control Options
•Maximum LED Current Set by AS2Cwire
Interface, 32 Steps
•PWM Interface Dimming from 100% to 1% Duty
Cycle with Frequency up to 100kHz
•0.9MHz Constant Frequency
•Automatic Soft-Start Limits Inrush Current
•Dual 150mA LDOs
▪ Enable and Output Voltage Set by AS2Cwire
Sixteen Combinations of 5 Output Voltages:
1.2V, 1.5V, 1.8V, 2.8V, and 3.0V
▪ Integrated Discharge Resistor when Disabled
•< 1.0µA in Shutdown
•Short-Circuit Protection
•Small Application Circuit
•-40°C to 85°C Temperature Range
•RoHS Compliant, Halogen-Free TQFN3.0x2.2-18
Package
Applications
• Camera Phones
• Digital Still Cameras (DSC)
• LED Photo Flash/Torch
• MP3 Players
•PDAs and Notebook PCs
• Smartphones
Typical Application
IN
C1+
C1-
C2+
C2-
OUTCP
D1
D2
D3
AGND
AAT2868
C1
1µF
C2
1µF
CIN
2.2µF
COUT
1µF
CF
56nF CLDOB
2.2µF
CLDOA
2.2µF
D4
D4
WLEDs
FCAP
GND
LDOA
LDOB
INLDO D3D2D1
LDOA
LDOB
VIN
2.7~5.5V
PWM PWM
EN/SET
AS2Cwire
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
2Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Pin Descriptions
Pin # Symbol Function Description
1 C1+ I Flying capacitor C1 positive terminal. Connect a 1µF capacitor between C1+ and C1-.
2 LDOB O LDOB output. Four output voltages can be programmed via the AS2Cwire interface: 1.2V, 1.5V,
1.8V and 2.5V. The default output voltage is 2.8V.
3 LDOA O LDOA output. Four output voltages can be programmed via the AS2Cwire interface: 1.5V, 1.8V,
2.5V, and 3.0V. The default output voltage is 1.8V.
4 PWM I Connect a PWM signal up to 100kHz or tie to GND if PWM is not used.
5 AGND AG Analog ground connection.
6 INLDO P Input power supply pin to LDOs. Connect this pin to IN. A 1µF capacitor is recommended for
bypass use from this pin to ground.
7 IN P Input power supply pin. Connect a 1µF bypass capacitor from this pin to ground.
8 GND PG Ground connection.
9 FCAP I PWM lter capacitor. Connect a 56nF capacitor to ground. If PWM is not used, leave open.
10 D1 I LED driver current sink D1. Connect LED cathode to this pin. If not used, tie to OUTCP.
11 D2 I LED driver current sink D2. Connect LED cathode to this pin. If not used, tie to OUTCP.
12 D3 I LED driver current sink D3. Connect LED cathode to this pin. If not used, tie to OUTCP.
13 D4 I LED driver current sink D4. Connect LED cathode to this pin. If not used, tie to OUTCP.
14 EN/SET I
Charge pump enable/set. When in the low state, AAT2868 is powered down, and consumes less
than 1µA. When EN/SET jumps from low to high, the charge pump is active and 20mA LED cur-
rent each are set. The two LDOs remain inactive until data 3 is written to address 4 through the
AS2Cwire interface. This pin should not be left oating.
15 C2- I Flying capacitor C2 negative terminal. Connect a 1µF capacitor between C1+ and C1-.
16 C2+ I Flying capacitor C2 positive terminal. Connect a 1µF capacitor between C2+ and C2-.
17 OUTCP O Charge pump output. Connect a 1µF bypass capacitor between this pin and ground.
18 C1- I Flying capacitor C1 negative terminal. Connect a 1µF capacitor between C2+ and C2-.
EP Exposed pad. Connect to ground directly beneath the package.
Pin Configurations
TQFN3.0 x 2.2-18
(Top View)
5
7
6
9
8
18
16
17
14
15
12
13
10
11
2
1
4
3
AGND
INLDO
IN
GND
FCAP
D1
D2
D3
D4
C2-
C2+
EN/SET
OUTCP
C1-
C1+
LDOB
LDOA
PWM
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
3
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 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. Based on long-term current density limitation.
3. Mounted on an FR4 board.
Absolute Maximum Ratings1
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), VPWM (MAX) Maximum EN or PWM to Input Voltage or GND VIN + 0.3 V
IOUT Maximum DC Output Current (continuous)2470 mA
TJMaximum Junction Operating temperature -40 to 150 OC
TLEAD Maximum Soldering Temperature (at leads, 10 sec) 300
Thermal Information3
Symbol Description Value Units
θJA Thermal Resistance from Junction to Ambient 66 OC/W
θJC Thermal Resistance from Junction to Case 39 OC/W
PDMaximum Power Dissipation 1.5 W
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
4Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
1. The AAT2868 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. Determined by the average of all active channels.
3. Current matching is defined as the deviation of any sink current from the average of all active channels.
4. The EN/SET pin must remain logic low (less than VIL) for longer than 500μs to guarantee the off timeout.
5. The EN/SET pin must remain logic high (greater than VIH) for longer than 500μs to guarantee the latch timeout.
Electrical Characteristics1
VIN = 3.6V; CIN = 1µF; COUT = 1µF; CFLY = 1µF; CFLT = 56nF; TA = -40°C to 85°C, unless otherwise noted. Typical values
are TA = 25°C.
Symbol Description Conditions Min Typ Max Units
Input Power Supply
VIN Input Voltage Range 2.7 5.5 V
VOUT(MAX) Maximum Output Voltage 5.5 V
Icc Operating Current
1x Mode, No Load Current, CP enabled 0.5 1
mA
1.5x Mode, ID1 = FS, excluding ID1, VD2 = VD3 =
VD4 = IN 2 4
ISHDN(MAX) Shutdown Current EN = 0 1.0 µA
Charge Pump Section
IOUT(MAX) Maximum Output Current VF = 3.6V 124 mA
fosc Oscillator Frequency 0.9 MHz
tSS Charge Pump Setup Time 100 µs
VIN_(TH) Charge Pump Mode Hysteresis 1.5x to 1x Transition, ID1 = ID2 = ID3 = ID4 =
31mA 300 mV
LED Current Sink Outputs
IDX ISINK Current Accuracy2Data 32 and PWM = 100%, TA = 25°C -10 +10
%
Data 1-3, TA = 25°C ±15
IDX(MATCH)
Current Marching Between Any Two
Current Sinks3VF; D1:D4 = 3.6V -5 +5
VD_(TH) Charge Pump Mode Transition 1x to 1.5x Mode, ID1 = ID2 = ID3 = ID4 = 31mA 120 250 mV
AS2Cwire Control and EN/SET Control
VEN/SET (L) EN/SET 0.4 V
VEN/SET (H) EN/SET 1.4 V
ILEAK EN/SET Input Leakage -1 1mA
tEN/SET(LOW) EN/SET Input Low Time 0.3 75 µs
tEN/SET(HI_MIN) EN/SET Minimum High Time 50 ns
tEN/SET(HI_MAX) EN/SET Maximum High Time 75 µs
tEN/SET(OFF) EN/SET Input Off Timeout4 500 µs
tEN/SET(LAT) EN/SET Latch Timeout5 500 µs
PWM Control
VPWM(L) PWM Input Low Threshold Voltage 0.4 V
VPWM(H) PWM High Threshold Voltage 1.4 V
TPWM(ON) PWM Turn On Delay 500 µs
FPWM(MIN) PWM Minimum Input Control Frequency 100 Hz
FPWM(MAX) PWM Maximum Input Control Frequency 100 kHz
FPWM(MIN) PWM Minimum Duty Cycle FPWM = 50kHz full scale 1 %
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
5
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
1. The AAT2868 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. VDO[A/B] is defined as VIN – LDO[A/B] when LDO[A/B] is 98% of nominal.
Electrical Characteristics (continued)1
VIN = 3.6V; CIN = 1µF; COUT = 1µF; CFLY = 1µF; CFLT = 56nF; TA = -40°C to 85°C, unless otherwise noted. Typical values
are TA = 25°C.
Symbol Description Conditions Min Typ Max Units
Linear Regulators
ΔVOUT[A/B]/
VOUT[A/B]
LDOA, LDOB Output Voltage Tolerance IOUT = 1mA to 150mA; TA = 25°C -2 2 %
IOUT = 1mA to 150mA; TA = -40°C to +85°C -3.0 3.0 %
IOUT[A/B](MAX) LDOA, LDOB Maximum Load Current 200 mA
VOUT[A/B](DO) LDOA, LDOB2VOUT[A/B] ≥ 3.0V; IOUT = 150mA 100 150 mV
∆VOUT/
VOUT*∆VIN
Line Regulation VIN = (VOUT[A/B] + 1V) to 5V 0.09 %/V
PSRR[A/B] LDOA, LDOB Power Supply Rejection Ratio IOUT[A/B] = 10mA, 1kHz 50 dB
ROUT_(DCHG) LDOA, LDOB Auto-Discharge Resistance 720 Ω
Thermal
TSD TJ Thermal Shutdown Threshold 140 °C
THYS TJ Thermal Shutdown Hysteresis 20 °C
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
6Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Typical Characteristics
CP Operating Current vs. Input Voltage
(1x Mode)
Input Voltage (V)
I
Q
(mA)
2.73.1 3.53.9 4.34.7 5.15.5
0.0
0.1
0.2
0.3
0.4
0.5
0.6
85°C
25°C
-40°C
CP Operating Current vs. Input Voltage
(1.5x Mode)
Input Voltage (V)
I
Q
(mA)
2.73.1 3.53.9 4.34.7 5.15.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
85°C
25°C
-40°C
CP Input Current vs. Input Voltage
Input Voltage (V)
Input Current (A)
2.73.1 3.53.9 4.34.7 5.15.5
0
40
80
120
160
200
VF = 3.3V, ILED = 31mA
VF = 3.2V, ILED = 20mA
VF = 3.1V, ILED = 10mA
VF = 2.9V, ILED = 5mA
Shutdown Current vs. Temperature
Temperature (°C)
I
SD
(µA)
-40-15 10 35 60 85
0.00
0.02
0.04
0.06
0.08
0.10 VIN = 3.6V
VIN = 5.5V
LDO Operating Current vs. Input Voltage
(LDOA + LDOB)
Input Voltage (V)
I
OP
(mA)
2.73.1 3.53.9 4.34.7 5.15.5
0.00
0.05
0.10
0.15
0.20
0.25
85°C
25°C
-40°C
LDO Operating Current vs. Input Voltage
(LDOA Only)
Input Voltage (V)
I
OP
(mA)
2.73.1 3.53.9 4.34.7 5.15.5
0.00
0.05
0.10
0.15
0.20
0.25
85°C
25°C
-40°C
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
7
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Typical Characteristics
CP Efficiency vs. Input Voltage
Input Voltage (V)
Efficiency (%)
2.73.1 3.53.9 4.34.7 5.15.5
40
50
60
70
80
90
100
VF = 3.3V, ILED = 31mA
VF = 3.2V, ILED = 20mA
VF = 3.1V, ILED = 10mA
VF = 2.9V, ILED = 5mA
Frequency vs. Temperature
Temperature (°C)
Frequency (KHz)
-40-15 10 35 60 85
850
870
890
910
930
950
CP Current Matching vs. Temperature
(VIN = 3.6V; VF = 3.3V; 31mA/ch)
Temperature (°C)
Current (mA)
-40-15 10 35 60 85
28.5
29.3
30.1
30.9
31.7
32.5
D1
D2
D3
D4
CP Current Matching vs. Temperature
(VIN = 3.6V; VF = 3.3V; 0.5mA/ch)
Temperature (°C)
Current (mA)
-40-15 10 35 60 85
0.30
0.34
0.38
0.42
0.46
0.50
D1
D2
D3
D4
LDO Line Regulation vs. Input Voltage
(VOUT = 1.2V)
Input Voltage (V)
Output Error (%)
2.73.1 3.53.9 4.34.7 5.
15
.5
-1.0
-0.6
-0.2
0.2
0.6
1.0
85°C
25°C
-40°C
LDO Load Regulation vs. Output Current
(VOUT = 1.2V)
Load Current (mA)
Output Error (%)
0.11 10 100 1000
-1.8
-1.2
-0.6
0.0
0.6
1.2
1.8
85°C
25°C
-40°C
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
8Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Typical Characteristics
EN Input High Threshold Voltage
vs. Input Voltage
Input Voltage (V)
V
EN(H)
(V)
2.73.1 3.53.9 4.34.7 5.
15
.5
0.2
0.4
0.6
0.8
1.0
1.2
-40°C
25°C
85°C
EN Input Low Threshold Voltage
vs. Input Voltage
Input Voltage (V)
V
EN(L)
(V)
2.73.1 3.53.9 4.34.7 5.
15
.5
0.2
0.4
0.6
0.8
1.0
1.2
-40°C
25°C
85°C
PWM Input High Threshold Voltage
vs. Input Voltage
Input Voltage (V)
V
PWM(H)
(V)
2.73.1 3.53.9 4.34.7 5.
15
.5
0.2
0.4
0.6
0.8
1.0
1.2
-40°C
25°C
85°C
PWM Input Low Threshold Voltage
vs. Input Voltage
Input Voltage (V)
V
PWM(L)
(V)
2.73.1 3.53.9 4.34.7 5.
15
.5
0.2
0.4
0.6
0.8
1.0
1.2
-40°C
25°C
85°C
EN/SET Input Latch Time vs. Input Voltage
Input Voltage (V)
t
EN/SET(LAT)
(µs)
2.73.1 3.53.9 4.34.7 5.15.5
120
160
200
240
280
320
85°C
25°C
-40°C
EN/SET Input Off Time vs. Input Voltage
Input Voltage (V)
t
EN/SET(OFF)
(µs)
2.73.1 3.53.9 4.34.7 5.15.5
120
180
240
300
360
85°C
25°C
-40°C
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
9
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Typical Characteristics
CP Turn On
(VIN = 3.6V; CIN = COUT = 1µF; CF = 56nF; 20mA/ch)
Time (100µs/div)
EN
(2V/div)
VOUT
(2V/div)
ILED
(20mA/div)
IIN
(200mA/div)
0
0
0
0
CP Turn Off
(VIN = 3.6V; CIN = COUT = 1µF; CF = 56nF; 31mA/ch)
Time (100µs/div)
EN
(2V/div)
VOUT
(2V/div)
ILED
(20mA/div)
IIN
(100mA/div) 0
0
0
0
CP Current Transient
(VIN = 3.6V; 0.5mA to 31mA)
Time (100µs/div)
VEN
(2V/div)
VOUT
(5V/div)
IIN
(200mA/div)
ILED
(20mA/div)
0
0
0
0
CP Current Transient
(VIN = 3.6V; 31mA to 0.5mA)
Time (40µs/div)
VEN
(2V/div)
VOUT
(5V/div)
IIN
(200mA/div)
ILED
(20mA/div)
0
0
0
0
LDO Turn On
(VIN = 3.6V; CIN = 2.2µF; CLDOA = CLDOB = 2.2µF;
VLDOA = 2.8V; VLDOB = 1.2V)
Time (40µs/div)
EN
(2V/div)
VLDOA
(2V/div)
VLDOB
(2V/div)
IIN
(1A/div) 0
0
0
0
LDO Turn On
(VIN = 3.6V; CIN = 2.2µF; CLDOA = CLDOB = 2.2µF;
VLDOA = 3.0V; VLDOB = 1.8V)
Time (40µs/div)
EN
(2V/div)
VLDOA
(2V/div)
VLDOB
(2V/div)
IIN
(1A/div) 0
0
0
0
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
10 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Typical Characteristics
LDO Turn Off
(VIN = 3.6V; CIN = 2.2µF; CLDOA = CLDOB = 2.2µF;
VLDOA = 2.8V; VLDOB = 1.2V)
Time (1ms/div)
EN
(2V/div)
VLDOA
(2V/div)
VLDOB
(2V/div)
0
0
0
1.5x Mode Operating Characteristics
(VIN = 3.2V; CIN = COUT = 1µF; 31mA/ch)
Time (1µs/div)
VIN
(AC coupled)
(50mV/div)
VOUT
(AC coupled)
(50mV/div)
IIN
(200mA/div)
ILED
(20mA/div)
0
0
0
0
1.5x Mode Operating Characteristics
(VIN = 3.2V; CIN = COUT = 1µF; PWM;
100kHz; Duty = 50%; 31mA/ch)
Time (1µs/div)
VIN
(AC coupled)
(50mV/div)
VOUT
(AC coupled)
(50mV/div)
IIN
(100mA/div)
ILED
(20mA/div)
0
0
0
0
CP Mode Transient
(VIN = 3.6V to 4.2V; CIN = COUT = 1µF; 31mA/ch)
Time (100µs/div)
VIN
(2V/div)
VOUT
(2V/div)
ILED
(20mA/div)
3.6V
0
0
4.2V
0
LDO Load Transient
(VIN = 3.6V; VOUTB = 1.2V; CIN = COUTB = 2.2µF;
10mA to 150mA)
Time (40µs/div)
VOUT
(2V/div)
IOUTB
(50mA/div)
0
0
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
11
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Typical Characteristics
Dropout Characteristics
(VOUTA = 2.8V)
Input Voltage (V)
Output Voltage (V)
2.72.8 2.93.0 3.
13
.2
2.4
2.6
2.8
3.0
3.2
3.4
IOUT = 0mA
IOUT = 10mA
IOUT = 50mA
IOUT = 100mA
IOUT = 150mA
IOUT = 200mA
Dropout Characteristics
(VOUTA = 3.0V)
Input Voltage (V)
Output Voltage (V)
2.72.8 2.93.0 3.
13
.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
IOUT = 0mA
IOUT = 10mA
IOUT = 50mA
IOUT = 100mA
IOUT = 150mA
IOUT = 200mA
PSRR vs. Frequency
(VIN = 3.6V, VRIPPLE = 500mVPP, CIN = COUT = 2.2μF, IL = 10mA)
Frequency (KHz)
PSRR (dB)
0.11 10 100
0
20
40
60
80
100
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
12 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Functional Block Diagram
Dual-mode
Charge Pump
1X/1.5X
C1+
OUTCP
D1
D2
D3
D4
AGND
EN/SET
C1-
C2+
C2-
IN
32-step AS2Cwire
Backlight Control
and LDO Setting
4
Control
Logic
PWM Filter
PWM
FCAP
LDOA
LDOB
INLDO
GND
Functional Description
The AAT2868 is a high efficiency charge pump white LED
driver for portable applications. It can drive up to 4 white
LEDs. And the integrated two LDOs can provide 1.2V,
1.5V, 1.8V, 2.8V and 3.0V output voltages with 16 com-
binations with up to 150mA load capability.
The charge pump of AAT2868 is a fractional charge pump
and can multiply the input voltage by 1 or 1.5 times. The
charge pump switches at a fixed frequency of 0.9MHz.
The internal mode-selection circuit automatically switches
the mode between 1x and 1.5x based on the input volt-
age, white LED forward voltage VF
, and the programmed
LED current. This mode switching maximizes the effi-
ciency throughout the entire LED load range. When the
input voltage is high enough, the charge pump operates
in 1x mode (no charge pump) to provide maximum effi-
ciency. If the input voltage is too low to supply the pro-
grammed LED current, typically when the battery dis-
charges and the voltage decays, the 1.5x charge pump
mode is automatically enabled. When the battery is con-
nected to a charger and the input voltage become high
enough again, the device will switch back to 1x mode.
Five registers are designed for charge pump enable/dis-
able control, LED current programming, LDO enable/
disable control of the two LDOs, and combined LDO out-
put voltage settings via the AS2Cwire interface. The LED
current value is controlled by either the AS2Cwire inter-
face, a PWM interface, or both. The AS2Cwire interface
records rising edges of the EN/SET pin and decodes
them into 32 individual current level settings from 0.4mA
to 31mA, while the PWM interface receives an input
switching frequency where the duty cycle is varied to
modulate the output current. To avoid switching noise
and flicker in the output LED, the input PWM frequency
is filtered via an internal resistor and small external
capacitor to provide a constant LED current. Once the
AAT2868 charge pump is enabled, the PWM input will
modulate the current up to the maximum current pro-
grammed by the AS2Cwire interface.
AS2C Registers
The AAT2628 has five registers with up to four bits each
to control the LED backlighting enable/disable, LED cur-
rent and two LDOs enable/disable, output voltages, etc.
as shown in Table 1. Each register data can be written
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
13
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1. The LED current accuracy is compromised at low code settings.
with 1 to 16 EN/SET rising edges. Some bits are inter-
nally reserved and customer should only write it by bit
zero, such as Address 0, bit D0, D1 and D3, etc.
Otherwise it may lead to unexpected result. Address 0 is
the default address; if EN/SET is pulled high after a low
level of at least 500µs tOFF duration, address 0 is written
by 0 and LED backlighting is enabled with the default
20mA LED current each.
Address 0 – Backlight Enable
The BL_ENB bit of address register 0 is adopted to enable
or disable white LED backlighting. 0 enables backlighting;
1 disables backlighting. The other bits of the register
should be written by zero.
Description BL_ENB
Backlight On [default] 0
Backlight Off 1
Table 2: AS2C Register Address 0 Settings.
Address 2 and 3 –
LED Current Level Settings
LED current level is set via the AS2Cwire interface in a
linear scale by 32 codes where LED current of each
higher code is higher than the lower one, as shown in
Table 2. In this manner, the LED current decreases lin-
early with each decreasing code.
LED
Current
Codes
Addr2 Addr3 LED
Current
(mA)BL4 BL3 BL2 BL1 BL0
1 0 0 0 0 0 0.4
2 0 0 0 0 1 0.9
3 0 0 0 1 0 1.9
4 0 0 0 1 1 2.9
5 0 0 1 0 0 3.9
6 0 0 1 0 1 4.9
7 0 0 1 1 0 6.0
8 0 0 1 1 1 7.0
9 0 1 0 0 0 8.0
10 0 1 0 0 1 9.0
11 0 1 0 1 0 10.0
12 0 1 0 1 1 11.0
13 0 1 1 0 0 12.0
14 0 1 1 0 1 13.0
15 0 1 1 1 0 14.0
16 0 1 1 1 1 15.0
17 1 0 0 0 0 16.0
18 1 0 0 0 1 17.0
19 1 0 0 1 0 18.0
20 1 0 0 1 1 19.0
21 1 0 1 0 0 20.0
[Default]
22 1 0 1 0 1 21.0
23 1 0 1 1 0 22.0
24 1 0 1 1 1 23.0
25 1 1 0 0 0 24.0
26 1 1 0 0 1 25.0
27 1 1 0 1 0 26.0
28 1 1 0 1 1 27.0
29 1 1 1 0 0 28.0
30 1 1 1 0 1 29.0
31 1 1 1 1 0 30.0
32 1 1 1 1 1 31.0
Table 3: AS2C Register Address 2 and Address 3
LED Current Settings1.
Address
Function
Data
Number
EN/SET
Rising Edges D3 D2 D1 D0
EN/SET
Rising Edges
0 [Default] 17 Backlight Enable 0 BL_ENB 0 0 1 or 5
1 - Reserved - - - - -
2 19 Backlight MSB 0 0 0 BL[4] 1 or 2
3 20 Backlight LSBs BL[3] BL[2] BL[1] BL[0] 1 ~ 16
4 21 LDO Enable Control 0 0 LDOA_EN LDOB_EN 1 ~ 4
5 22 LDO Output Voltage LDO[3] LDO[2] LDO[1] LDO[0] 1 ~ 16
Table 1: AAT2868 AS2C Registers.
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
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Address 4 – LDO Enable Control
The AAT2868 includes two low dropout (LDO) linear
regulators. These regulators are powered from the bat-
tery and produce a fixed output voltage set through the
AS2Cwire serial interface. AS2C address 4 register is
used to turn the two LDOs on/off via the AS2Cwire serial
interface. An internal resistor is used to discharge the
LDO output voltage when the LDO is disabled.
Description
Data
LDOA_EN LDOB_EN
EN/SET
Rising
Edges
LDOA Off, LDOB Off
[Default] 0 0 1
LDOA Off, LDOB On 0 1 2
LDOA On, LDOB Off 1 0 3
LDOA On, LDOB On 1 1 4
Table 4: AS2C Register Address 4 Settings.
Address 5 - LDO Voltage Output Settings
Register address 5 is used to set LDOA and LDOB output
voltage levels. Sixteen combinations of the two LDOs can
be programmed by the 4 bits of the register. LDOA can
be set to one of four levels: 1.5V, 1.8V, 2.8V or 3.0V.
LDOB can be set one of four levels: 1.2V, 1.5V, 1.8V or
2.8V. The LDO regulators require only a small 2.2μF
ceramic output capacitor for stable operation. If improved
load transient response is required, larger-valued capac-
itors can be used without stability degradation.
AS2Cwire EN/SET Interface
The AAT2868 is dynamically programmable using the
AS2Cwire single-wire interface. AS2Cwire records rising
edges detected at the EN/SET pin to address and load
the data registers. The timing diagram in Figure 1 shows
the typical transmission protocol.
Description
Data
LDO[3] LDO[2] LDO[1] LDO[0] EN/SET Rising Edges
LDOA = 3.0V, LDOB = 2.8V 0 0 0 0 1
LDOA = 3.0V, LDOB = 1.8V 0 0 0 1 2
LDOA = 3.0V, LDOB = 1.5V 0 0 1 0 3
LDOA = 3.0V, LDOB = 1.2V 0 0 1 1 4
LDOA = 2.8V, LDOB = 2.8V 0 1 0 0 5
LDOA = 2.8V, LDOB = 1.8V 0 1 0 1 6
LDOA = 2.8V, LDOB = 1.5V 0 1 1 0 7
LDOA = 2.8V, LDOB = 1.2V 0 1 1 1 8
LDOA = 1.8V, LDOB = 2.8V [default] 1 0 0 0 9
LDOA = 1.8V, LDOB = 1.8V 1 0 0 1 10
LDOA = 1.8V, LDOB = 1.5V 1 0 1 0 11
LDOA = 1.8V, LDOB = 1.2V 1 0 1 1 12
LDOA = 1.5V, LDOB = 2.8V 1 1 0 0 13
LDOA = 1.5V, LDOB = 1.8V 1 1 0 1 14
LDOA = 1.5V, LDOB = 1.5V 1 1 1 0 15
LDOA = 1.5V, LDOB = 1.2V 1 1 1 1 16
Table 5: AS2Cwire Register Address 5 LDOA and LDOB Output Voltage Settings.
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
15
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The AAT2868 latches address or data after the EN/SET
input has been held high for time tLAT (500µs) through
AS2Cwire interface. Address or data is differentiated by
the number of EN/SET rising edges. Address has EN/SET
rising edges from 17 to 22 and data has EN/SET rising
edges from 1 to 16. A typical write protocol of the
AS2Cwire interface is a burst of EN/SET rising edges
identifying a particular address, followed by a pause with
EN/SET held high for the tLAT timeout period, then a burst
of rising edges signifying data, and another tLAT timeout
after the data has been sent. Once an address is set,
multiple writes to that address are allowed since the
address is not reset after each write. Address edges are
needed when changing the address, or writing to an
address other than the default after shutdown. Address
0 is the default address after shutdown. If the part is
enabled with only one rising edge after shutdown, then
Address 0 will be programmed and LED backlight chan-
nels BL1-BL4 will be enabled to the default 20mA each.
When EN/SET is held low for a time longer than tOFF
(500µs), the AAT2868 enters shutdown mode with
charge pump and two LDOs all turning off and draws less
than 1µA of current from IN. At shutdown, the data and
address registers are reset to 0.
PWM Control
The AAT2868 also includes an independent 20mA LED
current PWM dimming control with EN/SET low or an
additional means of providing dimming control after
maximum LED current set by EN/SET. When EN/SET is
low, up to 100kHz PWM signal with varied duty cycle
through PWM pin may change the LED current between
0mA and 20mA each.
When PWM is used as an additional dimming control,
before the PWM signal is activated, the EN/SET pin must
be held for the tLAT period after setting the maximum cur-
rent available to the LEDs. For example, if the maximum
current of 20mA is required then a simple enable of the
EN/SET followed by tLAT will allow 20mA to flow through
each LED. By applying a variable duty cycle between 1%
and 100% on the PWM pin, this current can now be
adjusted. Frequencies of up to 100kHz can be applied. To
avoid output flicker and noise, the input control PWM
frequency is filtered by an internal resistor in conjunction
with an external filter capacitor. It is recommended that
a 56nF ceramic capacitor be used.
Short Circuit and
Over-Temperature Protection
The AAT2868 integrates short circuit protection to limit
the input current in the case of the charge pump output
or the two LDO outputs shorted to ground by fault. The
backlight and the two LDOs will recover to normal oper-
ating state once the fault is removed.
The AAT2868 also includes over-temperature protection
circuitry. When the junction temperature is too high, the
over-temperature protection circuitry is active and the IC
enters standby mode with no LED current or LDO output.
When the fault is removed, the LED backlighting and
LDO outputs all recover.
12 19 20
TLAT TLAT
TLO
THI
Address Data
Address
EN/SET
Data Reg
03
0n
12 n≤16
Figure 1: AS2Cwire Timing Diagram.
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
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Application Information
LED Selection
The AAT2868 is designed to drive high intensity white
flash LEDs with forward voltages up to 4.4V. Though
AAT2868 switches the charge pump mode 1x and 1.5x
mode automatically to maintain the continuous LED cur-
rent accuracy, to obtain higher efficiency lower VF of the
white LEDs should be selected.
Maximum LED Current Setting
32 maximum LED current codes from 0.4mA to 31mA can
be set by address registers 2 and 3 through the EN/SET
AS2Cwire interface as shown in Figure 3. To obtain linear
LED current change, the AAT2868 is designed not to
change the LED current when data is written only to
address 2. The control circuit writes data to both address
2 and address 3 registers only after address 3 is written
to determine which LED current code is programmed.
Address 2 BL4's default value is 0 after one EN/SET rising
edge.
Code 1 to 16 with LED current from 0.4mA to 15mA can
be set after sending address 3 with 20 rising edges and
sending data with 1 to 16 rising edges after tLAT. Code 17
to 32 with LED current from 16mA to 31mA can be
obtained after writing both address 2 and address 3. The
operation is performed via the following steps:
1. Select address 2 by sending 19 rising edges on EN/
SET and holding high for tLAT;
2. Send data 1 to set DL4 by sending 2 rising edges
and holding high for tLAT;
3. Select address 3 by sending 20 rising edges on EN/
SET and holding high for tLAT;
4. Send data 15 to obtain LED current code 32 setting
by sending 16 rising edges on EN/SET and holding
high for tLAT.
PWM
(Up to 100kHz)
12 19 20
TLAT TLAT
TLO
THI
Address Data
EN/SET
12 n≤16
Figure 2: PWM Control Timing
LED Current Code
I
LED
(V)
1357 911132468 10 12 14 15 1716 18 19 2120 22 23 2524 26 27 28 29 3130 32
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
Figure 3: AAT2868 Total 32 LED Current Codes vs. LED Current.
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
17
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LED Dimming by PWM
The external PWM input signal dims the LEDs linearly by
varying the duty cycle from 100% to 1%. Figure 4 shows
the varied PWM duty cycle vs. maximum 20mA LED cur-
rent.
CFLT is used as a RC filter capacitor to filter the PWM con-
trol signal to a constant voltage for internal LED current
control. With internal resistance of 200kΩ and the RC fil-
ter rejection frequency set to 1/20 of the PWM frequency,
the CFLT minimum value can be calculated by the following
formula:
CFLT =
20
2πR · fPWM
Table 7 shows some minimum CFLT values for different
PWM frequencies. For most applications, 56nF is a suit-
able value except for 100Hz PWM frequency where a
value greater than 160nF should be used. If PWM con-
trol is not used, CFLT is unnecessary.
fPWM (kHz) Minimum CFLT (nF)
0.1 159
1 15.9
10 1.6
30 0.5
50 0.3
80 0.2
100 0.2
Table 7: Minimum CFLT Value Examples.
Charge Pump Efficiency
1x Mode Efficiency
The AAT2868's 1x mode is operational at all times and
functions alone to enhance device power conversion effi-
ciency when VIN is higher than the voltage across the
load. When in 1x mode, voltage conversion efficiency is
defined as output power divided by input power.
η =
P
OUT
P
IN
An expression for the ideal efficiency (η) in 1X charge
pump mode can be expressed as:
η =
P
OUT
=
V
F
· I
OUT
≈
V
F
PIN VIN · IIN VIN
-or-
η(%) = 100
OUT
VIN
1.5x Charge Pump Mode Efficiency
The AAT2868 contains a fractional charge pump which
will boost the input supply voltage in the event where VIN
is less than the voltage required to supply the output.
The efficiency (η) can be simply defined as a linear volt-
age regulator with an effective output voltage that is
equal to one and one half times the input voltage.
Efficiency (η) for an ideal 1.5x charge pump can be cal-
culated by the following equation:
==
≈
V
F
· I
OUT
VIN · IIN
V
F
1.5 · VIN
V
F
· I
OUT
VIN · 1.5 · IOUT
η =
P
OUT
PIN
-or-
η(%) = 100
V
OUT
1.5 · VIN
PWM Duty Cycle (%)
I
LED
(V)
100 90 8095 85 75 70 6065 55 50 4045 35 30 2025 15 10
50
0
2
4
6
8
10
12
14
16
18
20
22
Figure 4: Linear Dimming by PWM Duty Cycle
(20mA Maximum LED Current).
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
18 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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Capacitor Selection
The AAT2868 needs seven capacitors for a typical appli-
cation: CIN, COUT
, C1, C2, CFLT and CLOA, CLOB. Among them,
CIN, C1, C2 and COUT are required for the 1.5x mode
charge pump. 1µF surface-mount multi-layer ceramic
capacitors with less than 100mΩ low equivalent series
resistance (ESR) are recommended. Though capacitor
ESR will not affect the ability of the capacitor to store
energy, it has a large effect on performance such as
equivalent output resistance, efficiency, and output volt-
age ripple of the charge pump. Tantalum and aluminum
electrolytic capacitors are not recommended for use with
the AAT2868 due to their high ESR. A output capacitance
value of 2.2µF or above is required for LDOA and LDOB
for proper load voltage regulation and stable operation.
Table 6 shows some recommended capacitors.
For most applications, ceramic capacitors with X5R tem-
perature characteristics are preferred for AAT2868 appli-
cation. These capacitors have good capacitance tolerance
over a wide temperature range (X5R: ±15% over -55°C
to +85°C). Capacitors with Y5V or Z5U temperature char-
acteristics are generally not recommended for AAT2869.
They have wide capacitance tolerance over special tem-
perature (Y5V: +22%, -82% over -30°C to +85°C, Z5U:
+22%, -56% over +10°C to +85°C).
Careful selection of the four external capacitors CIN, C1,
COUT is important because they will affect turn-on time,
output ripple and transient performance. Optimum per-
formance will be obtained when low ESR (<100mΩ)
ceramic capacitors are used. In general, low ESR may be
defined as less than 100mΩ. A capacitor value of 1uF for
all four 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.
Additional Applications
The current sinks of the AAT2868 can be combined to
drive higher current levels through a single LED. As an
example, Figure 5 shows the AAT2868 driving a single
white LED with up to 124mA by connecting D1-D4
together to the LED cathode.
Printed Circuit Board
Layout Recommendations
When designing a PCB for the AAT2868, the key require-
ments are:
1. Place the flying capacitors C1 and C2 as close to the
chip as possible; otherwise 1.5x mode performance
will be compromised.
2. Place input and output decoupling capacitors as close
to the chip as possible to reduce switching noise and
output ripple.
3. Connect the exposed pad to GND plane to get best
power dissipation.
Manufacturer Part Number Value (µF) Voltage Temp. Co.
ESR (mΩ)
at 1MHz Case
Murata
GRM188R61C105KA93 1 16 X5R 18 0603
GRM185R60J105KE21 1 6.3 X5R 16 0603
GRM188R61A225KE34 2.2 10 X5R 12 0603
TDK C1608X5R1C105K 1 16 X5R 5.5 0603
C1608X5R0J225K 2.2 6.3 X5R 3.3 0603
Table 6: AAT2868 Recommended Capacitors.
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
19
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IN
C1+
C1-
C2+
C2-
OUTCP
D1
D2
D3
AGND
AAT2868
C1
1µF
C2
1µF
CIN
2.2µF
COUT
1µF
CF
56nF CLDOB
2.2µF
CLDOA
2.2µF
D4
FCAP
GND
LDOA
LDOB
INLDO D1
Up to
124mA
LDOA
LDOB
VIN
2.7~5.5V
PWM PWM
EN/SET
AS2Cwire
Figure 5: Higher Current, Single LED Application.
Schematic and Layout
AS2Cwire
Microcontroller
AAT2868
White LED
Driver
1µF
C1
2.2µF
CIN
0.1µF
C3
1k
R10
1k
R9
50k
R7
V_MCU
SELECT
DETAIL
SEND
J1
1k
R11
1k
R1 2
VDD
1
GP5
2
GP4
3
GP3
4GP2 5
GP1 6
GP0 7
VSS 8
PIC12F675U2
Red
LED2
D1
1µF
C2
DC+
DC-
1µF
COUT
D2 D3 D4
56nF
CF
EN/SET
0
R1
0
R2
0
R3
0
R4
50k
R8
AAT2868
C1+
1
PWM
4EN/SET
14
FCAP
9
LDOB 2
LDOA 3
D4 13
D3 12
D2 11
EP
C1-
18
IN
7
D1 10
OUTCP 17
C2- 15
C2+ 16
GND
8
INLDO
6
AGND
5
U1
CLDOA
CLDOB
LDOA
LDOB
V_LDO
PWM
1k
R6
LED1
VOUT
2.2µF
2.2µF
Figure 6: AAT2868 Evaluation Board Schematic.
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
20 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Figure 7: AAT2868 Evaluation Board Figure 8: AAT2868 Evaluation Board
Top Side Layout. Bottom Side Layout.
Component Part Number Description Manufacturer
U1 AAT2868IDT-T1 High Efciency, 4 Channel, 1X/1.5X Charge Pump for White LED Skyworks
U2 PIC12F675 8-Pin Flash-Based 8-Bit CMOS Microcontroller Microchip
R1, R2, R3, R4 RC0603FR-070RL Res 0Ω 1/10W 1% 0603 SMD
YageoR7, R8 RC0603FR-0749K9L Res 49.9KΩ 1/10W 1% 0603 SMD
R6, R9, R10, R11, R12 RC0603FR-071KL Res 1KΩ 1/10W 1% 0603 SMD
C1, C2, COUT GRM188R71C105K Cap Ceramic 1μF 0603 X7R 16V 10%
Murata
CIN, CLA, CLB GRM188R61A225K Cap Ceramic 2.2μF 0603 X5R 10V 10%
C3 GRM188R71C104K Cap Ceramic 0.1μF 0603 X7R 16V 10%
CFGRM188R71C563K Cap Ceramic 0.056μF 0603 X7R 16V 10%
D1, D2, D3, D4 RS-0805UW 20mA White LED 0805 Realstar
LED1 0805KGCT Green LED 0805 HB
LED2 0805KRCT Red LED 0805 HB
CYCLE, UP, DOWN 6*6*5 12V 50mA Pushbutton E-LT
Table 8: AAT2868IDT-DB1 Evaluation Board Bill of Materials.
AAT2868
DATA SHEET
CABC Compatible Four-Channel Backlight Driver with Dual LDO Regulators
21
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202072B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 23, 2012
Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved.
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CLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM
THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Skyworks products are not intended for use in medical, lifesaving or life-sustaining applications, or other equipment in which the failure of the Skyworks products could lead to personal injury, death, physical or en-
vironmental damage. Skyworks customers using or selling Skyworks products for use in such applications do so at their own risk and agree to fully indemnify Skyworks for any damages resulting from such improper
use or sale.
Customers are responsible for their products and applications using Skyworks products, which may deviate from published specications as a result of design defects, errors, or operation of products outside of pub-
lished parameters or design speci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 speci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
identi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.
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
TQFN 3.0 x 2.2-18L 5CXXY AAT2868IDT-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
TQFN3.0 x 2.2-183
2.20 ± 0.05
3.00 ± 0.05
Index Area
1.10 ± 0.05
0.40 BSC 0.20 ± 0.05
1.90 ± 0.05
0.30 ± 0.05
Top View Bottom View
Side View
0.05 ± 0.05
0.203 REF
0.75 ± 0.05
Pin 1 Indicator
(optional)
All dimensions in millimeters.