General Description
The AAT3169 is a low noise, constant frequency
charge pump DC/DC converter that uses a tri-mode
load switch (1X), fractional (1.5X), and doubling
(2X) conversion to maximize efficiency for white
LED applications. The AAT3169 is capable of driv-
ing six LEDs for a total of 180mA from a 2.7V to
5.5V input. The current sinks may be operated indi-
vidually or in parallel for driving higher current LEDs.
A low external parts count (two 1F flying capacitors
and two small 1F capacitors at VIN and VOUT)
make this part ideally suited for small, battery-pow-
ered applications.
AnalogicTech's AS
2
CwireTM (Advanced Simple
Serial ControlTM) serial digital input is used to
enable, disable, and set current for each LED with
a 16-level logarithmic scale plus four low-current
settings down to 115A. For optimized efficiency,
low-current settings require only 65A of house-
keeping current.
Each output of the AAT3169 is equipped with built-
in protection for V
OUT
short-circuit and auto-disable
for load short-circuit conditions. Built-in soft-start
circuitry prevents excessive inrush current during
start-up. A low-current shutdown feature discon-
nects the load from V
IN
and reduces quiescent cur-
rent to less than 1A.
The AAT3169 is available in a Pb-free, space-sav-
ing, thermally-enhanced 16-pin 3x4mm TDFN or
4x4mm QFN package.
Features
V
IN
Range: 2.7V to 5.5V
Fully Programmable Current with Single Wire
-- 16-Step Logarithmic Scale
-- 20/30/15mA Max Current
-- Four Low-Current Settings Down to 115A
-- Low I
Q
(65A) for Single-Channel, Low-
Current Mode
Tri-Mode 1X, 1.5X, and 2X Charge Pump for
Maximum Efficiency and V
F
Coverage
Drives Up to Six LEDs
Individual Main-Sub (5-1) Group Control
No Inductors, Low Noise Operation
1MHz Constant Switching Frequency
Small Application Circuit
Built-In Thermal Protection
Built-In Auto-Disable for Open Circuit
Automatic Soft Start
I
Q
<1A in Shutdown
Thermally-Enhanced TDFN34-16 or
QFN44-16 Package
Applications
Color (RGB) Lighting
Programmable Current Sink
White LED Backlighting
White Photo Flash for Digital Still Cameras
AAT3169
High Efficiency 1X/1.5X/2X Charge
Pump for White LED Applications
Typical Application
C1
1
F
C2
1
F
D1
D2
D3
D4
D5
C
OUT
1
F
C
IN
1
F
2.7V to 5.5V
EN/SET
VIN
EN/SET
C1+
C1-
C2+
C2-
VOUT
D1
D2
D3
D4
D5
GND
AAT3169
D6
D6
3169.2006.04.1.0
1
ChargePump
TM
Pin Descriptions
Pin Configuration
TDFN34-16
QFN44-16
(Top View)
(Top View)
1
2
3
4
12
11
10
9
5
6
7
8
16
15
14
13
D6
EN/SET
N/C
VOUT
C2+
C1+
C1-
C2-
GND
VIN
GND
D1
D2
D3
D4
D5
N/C
VOUT
C2+
D6
EN/SET
3
C1+
C1-
C2-
D3
D2
D1
D5
D4
GND
VIN
GND
4
5
1
2
6
7
8
14
13
12
16
15
11
10
9
Pin #
Symbol
Function
1
D6
Current sink input #6.
2
EN/SET
AS
2
Cwire serial interface control pin.
3
N/C
No connection.
4
VOUT
Charge pump output to drive load circuit. Requires 1F capacitor connected between this
pin and ground.
5
C2+
Flying capacitor 2 positive terminal. Connect a 1F capacitor between C2+ and C2-.
6
C1+
Flying capacitor 1 positive terminal. Connect a 1F capacitor between C1+ and C1-.
7
C1-
Flying capacitor 1 negative terminal.
8
C2-
Flying capacitor 2 negative terminal.
9, 11
GND
Ground.
10
VIN
Input power supply. Requires 1F capacitor connected between this pin and ground.
12
D1
Current sink input #1.
13
D2
Current sink input #2.
14
D3
Current sink input #3.
15
D4
Current sink input #4.
16
D5
Current sink input #5.
EP
Exposed paddle (bottom); connect to ground as closely as possible to the package.
AAT3169
High Efficiency 1X/1.5X/2X Charge
Pump for White LED Applications
2
3169.2006.04.1.0
Absolute Maximum Ratings
1
Thermal Information
3
Symbol
Description
Value
Units
P
D
Maximum Power Dissipation
QFN44-16
2.0
W
TDFN34-16
JA
Maximum Thermal Resistance
QFN44-16
4
50
C/W
TDFN34-16
5
Symbol
Description
Value
Units
V
IN
Input Voltage
-0.3 to 6
V
V
EN/SET
EN/SET to GND Voltage
-0.3 to V
IN
+ 0.3
V
I
OUT
2
Maximum DC Output Current
180
mA
T
J
Operating Junction Temperature Range
-40 to 150
C
T
LEAD
Maximum Soldering Temperature (at leads, 10 sec)
300
C
AAT3169
High Efficiency 1X/1.5X/2X Charge
Pump for White LED Applications
3169.2006.04.1.0
3
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.
4. Derate 20mW/C above 25C.
5. Derate 6.25mW/C above 25C.
Electrical Characteristics
1
C
IN
= C
OUT
= C
1
= C
2
= 1.0F; T
A
= -40C to +85C, unless otherwise noted. Typical values are at T
A
= 25C,
V
IN
= 3.6V.
Symbol
Description
Conditions
Min
Typ Max Units
Input Power Supply
V
IN
Operation Range
2.7
5.5
V
1X Mode, 3.0
V
IN
5.5, Active,
0.3
No Load Current, High Current Mode
1.5X Mode, 3.0
V
IN
5.5, Active,
1
mA
I
CC
Operating Current
No Load Current, High Current Mode
2X Mode, 3.0
V
IN
5.5, Active,
1
No Load Current, High Current Mode
1X Mode, 3.0
V
IN
5.5, D6 Active,
65
90
A
No Load Current, Low Current Mode
I
SHDN
Shutdown Current
EN/SET = 0
1
A
Current Accuracy
I
SET
= 20mA, T
A
= 25C
-10
10
I
DX
I
SET
= 2.4mA, T
A
= 25C
-20
20
%
Low Current Accuracy
I
SET
= 400A, T
A
= 25C
-20
20
I
(D-Match)
Current Matching
2
V
F
:D1:D6 = 3.6V
0.5
1
%
V
TH
1X to 1.5X or 1.5X to 2X Transition
I
SET
= 20mA
150
mV
Threshold at Any I
SINK
Pin
Charge Pump Section
T
SS
Soft-Start Time
100
s
F
CLK
Clock Frequency
1000
kHz
EN/SET
V
EN(L)
Enable Threshold Low
V
IN
= 2.7V
0.4
V
V
EN(H)
Enable Threshold High
V
IN
= 5.5V
1.4
V
T
EN/SET LO
EN/SET Low Time
0.3
75
s
T
EN/SET_HI_MIN
Minimum EN/SET High Time
50
ns
T
EN/SET_HI_MAX
Maximum EN/SET High Time
75
s
T
OFF
EN/SET Off Timeout
500
s
T
LAT
EN/SET Latch Timeout
500
s
I
EN/SET
EN/SET Input Leakage
-1
1
A
AAT3169
High Efficiency 1X/1.5X/2X Charge
Pump for White LED Applications
4
3169.2006.04.1.0
1. The AAT3169 is guaranteed to meet performance specifications over the -40C to +85C operating temperature range and is assured
by design, characterization, and correlation with statistical process controls.
2. Current matching is defined as the deviation of any sink current from the average of all active channels.
Typical Characteristics
C
IN
= C
OUT
= C
1
= C
2
= 1.0F, V
IN
= 3.6V, T
A
= 25C, unless otherwise noted.
Current Matching vs. Temperature
Temperature (
C)
Current (mA)
19.2
19.4
19.6
19.8
20.0
20.2
-40
-20
0
20
40
60
80
Channel 2
Channel 1
Channel 5
Channel 3
Channel 4
Channel 6
Turn-Off from 1.5X Mode
(V
IN
= 3.5V; 20mA/Channel)
Time (100s/div)
EN
(2V/div)
I
IN
(100mA/div)
V
F
(1V/div)
Turn-On to 2X Mode
(V
IN
= 2.8V; 20mA/Channel)
Time (100s/div)
EN
(2V/div)
CP
(2V/div)
I
IN
(200mA/div)
V
SINK
(500mV/div)
Turn-On to 1.5X Mode
(V
IN
= 3.8V; 20mA/Channel)
Time (100s/div)
EN
(2V/div)
CP
(2V/div)
I
IN
(200mA/div)
V
SINK
(500mV/div)
Turn-On to 1X Mode
(V
IN
= 4.2V; 20mA/Channel)
Time (100s/div)
EN
(2V/div)
CP
(2V/div)
I
IN
(200mA/div)
V
SINK
(500mV/div)
Efficiency vs. Supply Voltage
Supply Voltage (V)
Efficiency (%)
50
60
70
80
90
100
2.8
3.0
3.2
3.4
3.6
3.8
4.0
4.2
4.9mA/ch
V
F
= 2.9V
20mA/ch
V
F
= 3.4V
10.9mA/ch
V
F
= 3.1V
AAT3169
High Efficiency 1X/1.5X/2X Charge
Pump for White LED Applications
3169.2006.04.1.0
5
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