LTC3208 Datasheet, PDF (8/24 Pages) Linear Technology – High Current Software Confi gurable Multidisplay LED Controller

LTC3208
PI FU CTIO S
BLUE, GRN, RED (Pins 21, 22, 23): Current Source
Outputs for the RGB Illuminator LEDs. The RGB currents
can be independently set via the serial port. Currents
up to 27mA can be programmed over 16 steps via the
three internal 4-bit exponential DACs. These outputs can
also be used as open drain I²C controlled logic outputs.
When configured this way, these outputs cannot be ex-
ternally disabled by connecting to CPO. Setting data to
0 in REGA1 disables RED, REGA2 disables GREEN and
REGB1 disables BLUE.
GND (Pins 25, 33): System Ground. Connect Pin 25 and
exposed pad Pin 33 directly to a low impedance ground
plane.
C2M, C1M, C2P, C1P (Pins 26, 27, 29, 31): Charge
Pump Flying Capacitor Pins. 2.2µF X7R or X5R ceramic
capacitors should be connected from C1P to C1M and
C2P to C2M.
ENRGBS (Pin 28): Logic Input. This pin is normally high
and is used to enable or disable the RED, GREEN and
BLUE LEDs or the SUB LEDs. The selection between RGB
or SUB is made via an internal programmable bit. When
the pin is toggled from low (disable) to high (enable), the
LTC3208 illuminates either the RGB display with a color
combination that was previously programmed, or the SUB
display at its previously programmed current. The logic
level is referenced to DV_CC.
CPO (Pin 32): Output of the Charge Pump Used to Power
All LEDs. A 4.7µF X5R or X7R ceramic capacitor should
be connected to ground.
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