Diodes AL3159 User Manual
AL3159
HIGH EFFICIENCY 1x/2x CHARGE PUMP
FOR WHITE LED APPLICATIONS
Description
The AL3159 is a low noise, constant frequency charge pump
DC/DC converter that uses a Dual mode load switch (1x), and (2x)
conversion for white LED applications. The AL3159 is capable of
driving nine LED channels at 20mA from a 2.7V to 5.5V input. The
current sinks may be operated using three simple logic control
inputs individually or in parallel for driving higher-current LEDs. Low
external part counts (one 1µF flying capacitor and two
2.2µF capacitors at V
small, battery-powered applications.
AL3159 digital inputs are used to enable or disable the
LED channels with a fixed default current settings at 20mA or other
factory programming options available.
Each output of the AL3159 is equipped with built-in protection for
V
short circuit and auto-disable for LED short conditions. Built-in
OUT
soft-start circuitry prevents excessive inrush current during start-up
and mode switching. A low-current shutdown feature disconnects
the load from V
The AL3159 is available in a lead-free, space-saving, thermally
enhanced 20-pin 3 x 3mm QFN package.
Features
NEW PRODUCT
• V
range: 2.7V to 5.5V
IN
• Up to 93% Max Power Efficiency
• 1% Current Matching Accuracy Between Channels
• Drives up to 9 configurable Channels of LEDs
• Three simple logic decoding LED On/Off control inputs
• Low transition threshold voltage typical 150 mV
• Dual-Mode 1x and 2x Charge Pump
• 1.2 MHz Constant Switching Frequency
• V
• Soft Start for reducing inrush current
• I
• Thermally-Enhanced QFN3030-20 Package: Available in
• Lead Free Finish/ RoHS Compliant (Note 1)
Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
short circuit and Thermal Protections
OUT
<1µA in Shutdown
Q
“Green” Molding Compound (No Br, Sb)
http://www.diodes.com/products/lead_free.html
and V
IN
to reduce quiescent current less than 1µA.
IN
) make this part ideally suited for
OUT
Pin Assignments
Applications
• Mobile Phone White LED Backlighting and Indicators
• PDA White LED backlighting
• Battery-operated Phone Main and Sub Screen White LED
Backlighting
Typical Application Circuit
AL3159
Document number: DS35048 Rev. 2 - 2
1 of 10
www.diodes.com
January 2011
© Diodes Incorporated
Pin Descriptions
Pin Name Pin Number Description
D8 1 Current sink input #8. Connected to V
D9 2 Current sink input #9. Connected to V
CTL1 3 Control Pin 1
CTL3 4 Control Pin 3
CTL2 5 Control Pin 2
PGND 6 Charge Pump Switch Ground
CN 7 Negative Terminal of Flying Capacitor
VIN 8 Input Power Supply. Requires 2.2µF capacitor between this pin and ground.
CP 9 Positive Terminal of Flying Capacitor
NC 10,19 No-Connect
V
OUT
D1 12 Current sink input #1. Connected to V
D2 13 Current sink input #2. Connected to V
D3 14 Current sink input #3. Connected to V
D4 15 Current sink input #4. Connected to V
NEW PRODUCT
D5 16 Current sink input #5. Connected to V
GND 17 Ground
D6 18 Current sink input #6. Connected to V
D7 20 Current sink input #7. Connected to V
GND EP PAD Exposed Pad (bottom). Connected to GND directly underneath the package.
11
Charge pump output to drive load circuit. Requires 2.2µF capacitor between this pin
and ground.
AL3159
HIGH EFFICIENCY 1x/2x CHARGE PUMP
FOR WHITE LED APPLICATIONS
when un-used.
OUT
when un-used.
OUT
when un-used.
OUT
when un-used.
OUT
when un-used.
OUT
when un-used.
OUT
when un-used.
OUT
when un-used.
OUT
when un-used.
OUT
Functional Block Diagram
AL3159
Document number: DS35048 Rev. 2 - 2
2 of 10
www.diodes.com
January 2011
© Diodes Incorporated
HIGH EFFICIENCY 1x/2x CHARGE PUMP
FOR WHITE LED APPLICATIONS
Absolute Maximum Ratings (Note 2)
Symbol Description Rating Unit
ESD HBM Human Body Model ESD Protection 2 KV
ESD MM Machine Model ESD Protection 200 V
VIN Input Voltage -0.3 to 6 V
V
Notes: 2. Exceeding Absolute Maximum Ratings will cause permanent damage to the device.
Recommended Operating Conditions
Symbol Parameter Min Max Unit
NEW PRODUCT
Electrical Characteristics (T
Symbol Parameter Test Conditions Min Typ. Max Unit
I
SHDN
I
D-Match
R
VTH
VHS Mode Transition Hysteresis 250 mV
TSS Soft-Start Time 100 µs
Fsw Switching Frequency 1.2 MHz
V
CTL1, 2,3 (L)
V
CTL1,2,3(H)
T
CTL1,2,3
UVLO VIN Under-Voltage Lockout 1.8 2 2.2 V
I
CTL1,2,3
T
T
Notes: 3. Determined by the average current levels of all active channels
4. Defined as the deviation of any sink current from the average of all active current channels.
5. Device mounted on FR-4 substrate, 2"*2", 2oz copper, double-sided PC board, with minimum recommended pad on top layer and
4 vias to bottom layer.
CTL1, CTL2, CTL3 to GND Voltage -0.3 to VIN +0.3 V
CTL1,2,3
I
Maximum DC Output Current 270 mA
OUT
TJ Operating Junction Temperature Range 150
T
Maximum Soldering Temperature (at leads, 10 sec) 300
LEAD
VIN Input Voltage 2.7 5.5 V
TA Operating Amb ient Temperature -40 85 °C
= 25°C, V
A
IQ Quiescent Current
= 3.6V, CIN = C
IN
= 2.2µF, C1 = 1µF Unless otherwise noted)
OUT
1x Mode, 3.0≤VIN≤5.5, Active,
No Load Current
2x Mode, 3.0≤VIN≤5.5, Active,
No Load Current
0.3 0.6
2 5
Shutdown Current CTL1, CTL2 and CTL3 = 0 1 µA
I
IDX
Open Loop V
out
Current Accuracy (Note 3)
SINK
Current Matching Between Any Two
Current Sink Inputs (Note 4)
Resistance
OUT
1x to 2x Transition Threshold at Any
Pin
I
SINK
19 20 21 mA
VF: D1:D9 = 3.6V 1 2 %
1x mode 0.5
2 x mode 4.5
= 20mA 150 mV
I
DX
CTL1,2,3 Threshold Low VIN = 2.7V 0.4 V
CTL1,2,3 Threshold High VIN = 5.5V 1.4 V
CTL1,2,3 Off Timeout 200 µs
CTL1,2,3 Input Leakage -1 1 µA
SHDN
HYS
θ
JA
Thermal shutdown Protection 160
Thermal shutdown hysteresis 10
Thermal Resistance Junction-to-
Ambient
QFN3030-20 (Note 5)
48
AL3159
°C
°C
mA
Ω
°C
°C
o
C/W
AL3159
Document number: DS35048 Rev. 2 - 2
3 of 10
www.diodes.com
January 2011
© Diodes Incorporated
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