SC620_09 Datasheet, PDF (1/18 Pages) Semtech Corporation – Octal LED Driver,General Purpose Current Sink With Serial Interface

SC620
Octal LED Driver, General Purpose
Current Sink with Serial Interface
POWER MANAGEMENT
Features
„ Wide current setting range — 31.25μA to 25mA
„ Eight identical current drivers with independent
control
„ 5% current matching, 7% 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
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.
The SC620 also employs an adjustable global current gain
setting register to allow the current setting step size to
vary from 31.25μA to 500μA. This provides 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 float-
ing cathode technology. This feature allows each output
pin to vary in voltage from 150mV to V - 1.5V.
IN
All current control is programmed using an I²C interface
bus. Only a single input bypass capacitor is required — no
other external 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-con-
scious backlighting designs.
Typical Application Circuit
Battery
1μF
SCL
SDA
EN
SC620
IN
ILED1
SCL
ILED2
SDA
ILED3
EN
ILED4
GND
ILED5
GND
ILED6
GND
ILED7
GND
ILED8
LED Backlighting
Main Panel
Sub Panel Color/R/G/B LEDs
April 22, 2009
© 2009 Semtech Corporation
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