AL3159FSG-7 Diodes Inc, AL3159FSG-7 Datasheet - Page 6

• Manufacturer Part Number: AL3159FSG-7
• Description: Charge Pumps High EFF 2.7V - 5.5V 9-Ch LED 1.2 Mhz
• Manufacturer: Diodes Inc

Specifications of AL3159FSG-7

• Output Current: 270 mA
• Supply Current: 2 mA
• Maximum Operating Temperature: + 85 C
• Package / Case: QFN-20
• Input Voltage: 2.7 V to 5.5 V
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Switching Frequency: 1.2 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Functional Description
The AL3159 is a dual-mode high efficiency charge pump
(1x and 2x) device, driving nine LED channels with three
simple
LED backlight applications. An internal comparator circuit
compares the voltage at each constant current sink input
against a reference voltage. To ensure maximum power
efficiency, the most appropriate switching mode (1x and
2x) is automatically selected.
The AL3159 requires only three external components: one
1 µF ceramic flying capacitor (C
one 2.2µF ceramic input capacitor (C
2.2µF ceramic charge pump output capacitor (C
The each output channel of the AL3159 can drive nine
individual LEDs with a maximum current of fixed
manufacture setting (20mA or 30mA) per channel. These
can be paralleled to give a total maximum output current of
270mA.
AL3159
Document number: DS35048 Rev. 2 - 2
CTL<3:1>
000
001
010
011
100
101
110
111
logic
control
LED ON/OFF CONTROL
LED1~LED2 ON
LED3~LED5 ON
LED6~LED9 ON
LED6~LED8 ON
LED1~LED5 ON
inputs,
LED9 ON
ALL OFF
ALL ON
1
) for the charge pump,
intended
IN
), and one
OUT
for
).
white
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6 of 10
Disabled Current Sinks
Unused current channels must be disabled by connecting
the sinks to VOUT with only a small sense current flowing
through the disabled channel.
Soft-Start
Soft-start is incorporated to prevent excessive inrush
current
transitioning out of stand-by mode.
Short-Circuit Protection
Short-circuit protection function is incorporated to prevent
excessive load current when either flying cap terminals or
output pin electrically tied to a very lower voltage or
ground.
Over-Voltage Protection
Over-Voltage Protection function is incorporated to limit
the output voltage under a safe value to avoid on-chip
device breakdown.
Under-Voltage Lockout
Under-Voltage lockout feature disables the device when
the input voltage drops below UVLO threshold.
Thermal Auto Shutdown
When the die temperature exceeds the thermal limit, the
device will be disabled and enter stand-by mode. The
operation resumes whenever the die cools off sufficiently.
HIGH EFFICIENCY 1x/2x CHARGE PUMP
during
FOR WHITE LED APPLICATIONS
power-up,
mode
AL3159
switching,
© Diodes Incorporated
January 2011
and