LTC3205EUF Linear Technology, LTC3205EUF Datasheet - Page 6

• Manufacturer Part Number: LTC3205EUF
• Description: IC LED DRVR WT/RGB BCKLGT 24-QFN
• Manufacturer: Linear Technology
• Type: Backlight, White LED, RGB (Serial Interface)r

Specifications of LTC3205EUF

• Topology: PWM, Step-Down (Buck), Step-Up (Boost), Switched Capacitor (Charge Pump)
• Number Of Outputs: 9
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: RGB, White LED
• Frequency: 600kHz ~ 1.1MHz
• Voltage - Supply: 2.8 V ~ 4.5 V
• Mounting Type: Surface Mount
• Package / Case: 24-QFN
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 250mA
• Internal Switch(s): Yes
• Efficiency: 92%
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Voltage - Output: -

LTC3205
PI FU CTIO S
V
pin should be connected directly to the battery and by-
passed with a 1 F X5R or X7R ceramic capacitor.
SGND (Pin 17): Ground for the Control Logic. This pin
should be connected directly to a low impedance ground
plane.
RED, GREEN, BLUE (Pins 18, 19, 20): Current Source
Outputs for the RGB Illuminator LEDs. The currents for
the RGB LEDs are controlled by the resistor on the I
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 a total of 4096
BLOCK DIAGRA
6
IN
U
(Pin 16): Supply Voltage for the Charge Pump. The V
U
U
W
STEPUP 11
ENRGB 10
SGND 17
DV
SCLK 8
I
RGB
I
V
D
MS
LD 9
CC
IN
IN
16
14
13
12
7
CONTROL
LOGIC
2
COMMAND LATCH
SHIFT REGISTER
+
+
+
–
–
–
2
OSCILLATOR
16
800kHz
RGB
IN
4
PWM
ENABLECP
4
colors for the illuminator. See Tables 1 and 3. The RGB
LEDs are modulated at 1/240 the speed of the charge
pump oscillator.
SUB1, SUB2 (Pins 22, 21): Current Source Outputs for
the Sub Display White LEDs. The current for the sub
display is controlled by the resistor on the I
LEDs on the sub display can be set to 100%, 50%, 25% or
0% of full scale under software control. See Tables 1
and 2.
PGND (Pin 25, Exposed Pad): Power Ground for the
Charge Pump. The exposed pad should be connected
directly to a low impedance ground plane.
4
C1
5
+
1:1 AND 2:3 CHARGE PUMP
2
C1
4
2
–
C2
6
+
C2
3
–
25
15
24 MAIN3
23 MAIN4
22 SUB1
21 SUB2
18 RED
19 GREEN
20 BLUE
2 MAIN1
1 MAIN2
3205 BD
PGND
CPO
MS
pin. The
3205f