LTC3206 Datasheet, PDF (5/16 Pages) Linear Technology – I2C Multidisplay LED Controller

LTC3206
PI FU CTIO S
SUB1, SUB2 (Pins 1, 2): Current Source Outputs for the
SUB Display White LEDs. The current for the SUB display
is controlled by the resistor on the I_MS pin.The LEDs on the
SUB display can be set to exponentially increasing bright-
ness levels from 0.78% to 100% of full-scale. See Table 1.
C1⁺, C1^–, C2⁺, C2^– (Pins 5, 4, 6, 3): Charge Pump Flying
Capacitor Pins. A 2.2µF X7R or X5R ceramic capacitor
should be connected from C1⁺ to C1^– and another from
C2⁺ to C2^–.
DV_CC (Pin 7): This pin sets the logic reference level of the
SDA, SCL and ENRGB/S pins.
SDA (Pin 8): Input Data for the I²C Serial Port. Serial data
is shifted in one bit per clock to control the LTC3206 (see
Figures 3 and 4). The logic level for SDA is referenced to
DV_CC.
SCL (Pin 9): Clock Input for the I²C Serial Port (see Figures
3 and 4). The logic level for SCL is referenced to DV_CC.
ENRGB/S (Pin 10): This pin is used to enable and disable
either the RED, GREEN and BLUE current sources or the
SUB display depending on which is programmed to re-
spond via the I²C port. Once ENRGB/S is brought high, the
LTC3206 illuminates the RGB or SUB display with the
color combination or intensity that was previously pro-
grammed via the I²C port. The logic level for ENRGB/S is
referenced to DV_CC.
I_MS (Pin 11): This pin controls the maximum amount of
LED current in both the MAIN and SUB LED displays. The
I_MS pin servos to 0.6V when there is a resistor to ground.
The full scale (100%) currents in the MAIN and SUB
display LEDs will be 400 times the current at the I_MS pin.
I_RGB (Pin 12): This pin controls the amount of LED current
at the RED, GREEN and BLUE LED pins. The I_RGB pin
servos to 0.6V when there is a resistor to ground. The
current in the RED, GREEN and BLUE LEDs will be 400
times the current at the I_RGB pin when programmed to full
scale.
SGND (Pin 13): Ground for the control logic. This pin
should be connected directly to a low impedance ground
plane.
CPO (Pin 14): Output of the Charge Pump. This output
should be used to power white, blue and “true” green
LEDs. Red LEDs can be powered from V_IN or CPO. An X5R
or X7R low impedance (ceramic) 2.2µF charge storage
capacitor is required on CPO.
V_IN (Pin 15): Supply Voltage for the Charge Pump. The V_IN
pin should be connected directly to the battery and by-
passed with a 2.2µF X5R or X7R ceramic capacitor.
RED, GREEN, BLUE (Pins 16, 17, 18): Current Source
Outputs for the RGB Illuminator LEDs. The currents for the
RGB LEDs are controlled by the resistor on the I_RGB pin.
The RGB LEDs can independently be set to any duty cycle
from 0/15 through 15/15 under software control giving a
total of 16 shades per LED and 4096 colors for the
illuminator. See Table 1. The RGB LEDs are modulated at
1/240 the speed of the charge pump oscillator (approxi-
mately 4kHz).
MAIN1-MAIN4 (Pins 22, 21, 20, 19): Current Source
Outputs for the Main Display White LEDs. The current for
the main display is controlled by the resistor on the I_MS
pin. The LEDs on the MAIN display can be set to 16
exponentially increasing brightness steps from 0.78% to
100% of full scale. See Table 1.
AUX1, AUX2 (Pins 23, 24): Current source outputs for the
auxiliary white LEDs. The auxiliary current sources can be
individually assigned to be either MAIN display or SUB
display LEDs via the I²C serial port. When either AUX1 and/
or AUX2 are assigned to the MAIN display they will have
the same power setting as the other MAIN LEDs. Likewise,
when either AUX1 and/or AUX2 are assigned to the SUB
display they will have the same power setting as the other
SUB LEDs. The currents for the AUX1 and AUX2 pins are
controlled by the resistor on the I_MS pin.
PGND (Pin 25, Exposed Pad): Power Ground for the
Charge Pump. This pin should be connected directly to a
low impedance ground plane.
3206f
5