SC620 Datasheet, PDF (1/16 Pages) Semtech Corporation – Octal LED Driver, General Purpose Current Sink with Serial Interface

POWER MANAGEMENT
Description
The SC620 is a multi-purpose LED driver with eight identi-
cal, independently controlled current sinks. Each current
sink can drive an LED by connecting the LED’s anode to
the system power supply and the cathode to the current
sink input pin. Any combination of outputs can be enabled
or disabled for optimal design flexibility.
In addition to the individual current settings, the SC620
employs an adjustable global current gain setting register
to allow the current setting step size to vary from 31.25μA
to 500μA, giving the designer a wide range of options for
LED variation and dimming functions. The maximum output
is also scaled by this step size, with a maximum of 25mA
at the highest step setting.
Multi-colored and white LEDs with different forward volt-
ages can be driven using the same SC620 due to its floating
cathode technology. This feature allows each output pin to
vary in voltage from 150mV to V_IN - 1.5V.
All current control is done via an I²C interface bus. Only a
single input bypass capacitor is required - no other exter-
nal resistors or capacitors are needed. The 3mm x 3mm
MLPQ package and minimal support components make
the SC620 an ideal solution for low-cost, area-conscious
backlighting designs.
Typical Application Circuit
SC620
Octal LED Driver, General Purpose
Current Sink with Serial Interface
Features
Eight identical current drivers with independent
control
Wide current setting range - 31.25μA to 25mA
3% current matching, 5% accuracy
I²C interface for microprocessor control
I²C slave address 1110 000x
Less than 1μA quiescent current in shutdown
Low dropout voltage: ≤ 150mV
Over-temperature protection
MLPQ-UT-16 package (3mm x 3mm)
Ultra-thin 0.6mm maximum package height
Fully WEEE and RoHS compliant
Applications
LCD backlighting LED driver
Multicolor and RGB LED driver
General purpose current sink array
General purpose digital output (open-drain) expander
Auto-focus voice-coil driver
LED Backlighting
Main Panel
Sub Panel Color/R/G/B LEDs
Battery
1μF
SCL
SDA
EN
2
SC620
5
VIN
ILED1
11
SCL
6
ILED2
10
SDA
7
ILED3
3
EN
8
ILED4
1
GND
13
ILED5
4
GND
14
ILED6
9
GND
15
ILED7
12
GND
16
ILED8
January 16, 2007
www.semtech.com
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