AAT3123
器件资料摘要：
AAT3123/4
High Efficiency 1X/1.5X Fractional Charge
Pump for White LED Applications
3123.2003.09.1.1 1
ChargePump
™
General Description
The AAT3123/24 is a low noise, constant frequen-
cy charge pump DC/DC converter that uses a dual
mode Load Switch (1X) and fractional (1.5X) con-
version to maximize efficiency for White LED appli-
cations. The device can be used to produce current
levels up to 20mA to drive up to 6 LEDs from a
2.7V to 5.5V input. Outputs may be operated indi-
vidually or paralleled for driving higher-current
LEDs. Low external parts counts (two 1µF flying
capacitors and two small 1µF capacitors at V
IN
,
and OUT) make the AAT3123/24 ideally suited for
small battery-powered applications.
AnalogicTech™’s Simple Serial Control™
(S
2
Cwire™) interface is used to enable, disable
and set the LED drive current with a 32 level loga-
rithmic scale LED brightness control. The
AAT3123/24 has a thermal management system to
protect the device in the event of a short circuit
condition at the output pin. Built-in soft-start circuit-
ry prevents excessive inrush current during start-
up. A high charge pump switching frequency
enables the use of very small external capacitors.
A low current shutdown feature disconnects the
load from V
IN
and reduces quiescent current to less
than 1µA. The AAT3123 is available in very small
12 pin TSOPJW package. The six output AAT3124
is available in a 16 pin 4x4mm QFN package.
Features
• Dual Mode 1x and 1.5x Charge Pump for
Maximum Efficiency
• Drives Low-V
F
& High-V
F
Type LEDs
• Up to 6 20mA Outputs
• 32 Position Logarithmic Scale with Digital
Control
• Simple Serial Control™ (S
2
Cwire™) interface
• Low Noise Constant Frequency Operation
• 1MHz Switching Frequency
• Small Application Circuit
• Regulated Output Current
• Automatic Soft-Start
•V
IN
Range: 2.7V to 5.5V
• No Inductors
• Iq < 1µA in Shutdown
• Temperature Range -40 to 85°C.
• 16 pin 4x4 QFN package (AAT3124)
• 12 pin TSOPJW-12 package (AAT3123)
Applications
• White LED Backlighting
• White Photo-Flash for DSCs
• Color (RGB) Lighting
• Programmable Current Source
Typical Application
C
IN
1µF
V
BATTERY C
OUT
1µF
EN/SET
C1
1µF
C2
1µF
D6 D5 D4 D3
V
IN
V
OUT
C1+
C1-
C2+
C2-
D1
D2
D3
D4
EN/SET
GND
AAT3124
D5
D6
D2 D1
High Efficiency 1X/1.5X Fractional Charge
Pump for White LED Applications
3123.2003.09.1.1 1
ChargePump
™
General Description
The AAT3123/24 is a low noise, constant frequen-
cy charge pump DC/DC converter that uses a dual
mode Load Switch (1X) and fractional (1.5X) con-
version to maximize efficiency for White LED appli-
cations. The device can be used to produce current
levels up to 20mA to drive up to 6 LEDs from a
2.7V to 5.5V input. Outputs may be operated indi-
vidually or paralleled for driving higher-current
LEDs. Low external parts counts (two 1µF flying
capacitors and two small 1µF capacitors at V
IN
,
and OUT) make the AAT3123/24 ideally suited for
small battery-powered applications.
AnalogicTech™’s Simple Serial Control™
(S
2
Cwire™) interface is used to enable, disable
and set the LED drive current with a 32 level loga-
rithmic scale LED brightness control. The
AAT3123/24 has a thermal management system to
protect the device in the event of a short circuit
condition at the output pin. Built-in soft-start circuit-
ry prevents excessive inrush current during start-
up. A high charge pump switching frequency
enables the use of very small external capacitors.
A low current shutdown feature disconnects the
load from V
IN
and reduces quiescent current to less
than 1µA. The AAT3123 is available in very small
12 pin TSOPJW package. The six output AAT3124
is available in a 16 pin 4x4mm QFN package.
Features
• Dual Mode 1x and 1.5x Charge Pump for
Maximum Efficiency
• Drives Low-V
F
& High-V
F
Type LEDs
• Up to 6 20mA Outputs
• 32 Position Logarithmic Scale with Digital
Control
• Simple Serial Control™ (S
2
Cwire™) interface
• Low Noise Constant Frequency Operation
• 1MHz Switching Frequency
• Small Application Circuit
• Regulated Output Current
• Automatic Soft-Start
•V
IN
Range: 2.7V to 5.5V
• No Inductors
• Iq < 1µA in Shutdown
• Temperature Range -40 to 85°C.
• 16 pin 4x4 QFN package (AAT3124)
• 12 pin TSOPJW-12 package (AAT3123)
Applications
• White LED Backlighting
• White Photo-Flash for DSCs
• Color (RGB) Lighting
• Programmable Current Source
Typical Application
C
IN
1µF
V
BATTERY C
OUT
1µF
EN/SET
C1
1µF
C2
1µF
D6 D5 D4 D3
V
IN
V
OUT
C1+
C1-
C2+
C2-
D1
D2
D3
D4
EN/SET
GND
AAT3124
D5
D6
D2 D1